Medicinal Cannabis
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Medical cannabis, medicinal cannabis or medical marijuana (MMJ) refers to cannabis products and cannabinoid molecules that are
prescribed A prescription, often abbreviated or Rx, is a formal communication from physicians or other registered healthcare professionals to a pharmacist, authorizing them to dispense a specific prescription drug for a specific patient. Historically, ...
by
physician A physician, medical practitioner (British English), medical doctor, or simply doctor is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through the Medical education, study, Med ...
s for their patients. The use of cannabis as medicine has a long history, but has not been as rigorously tested as other medicinal plants due to legal and governmental restrictions, resulting in limited
clinical research Clinical research is a branch of medical research that involves people and aims to determine the effectiveness (efficacy) and safety of medications, devices, diagnostic products, and treatment regimens intended for improving human health. The ...
to define the safety and efficacy of using cannabis to treat diseases. Preliminary evidence has indicated that cannabis might reduce
nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...
and
vomit Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pregna ...
ing during
chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...
and reduce
chronic pain Chronic pain is pain that persists or recurs for longer than 3 months.https://icd.who.int/browse/2025-01/mms/en#1581976053 It is also known as gradual burning pain, electrical pain, throbbing pain, and nauseating pain. This type of pain is in cont ...
and
muscle spasm A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a musc ...
s. Regarding non-inhaled cannabis or cannabinoids, a 2021 review found that it provided little relief against chronic pain and sleep disturbance, and caused several transient
adverse effect An adverse effect is an undesired harmful effect resulting from a medication or other intervention, such as surgery. An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. The term compli ...
s, such as cognitive impairment,
nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...
, and
drowsiness Somnolence (alternatively sleepiness or drowsiness) is a state of strong desire for sleep, or sleeping for unusually long periods (compare hypersomnia). It has distinct meanings and causes. It can refer to the usual state preceding falling asleep ...
. Short-term use increases the risk of minor and major adverse effects. Common side effects include
dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to Balance disorder, disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a ...
, feeling tired, vomiting, and
hallucination A hallucination is a perception in the absence of an external stimulus that has the compelling sense of reality. They are distinguishable from several related phenomena, such as dreaming ( REM sleep), which does not involve wakefulness; pse ...
s. Long-term effects of cannabis are not clear. Concerns include memory and cognition problems, risk of addiction,
schizophrenia Schizophrenia () is a mental disorder characterized variously by hallucinations (typically, Auditory hallucination#Schizophrenia, hearing voices), delusions, thought disorder, disorganized thinking and behavior, and Reduced affect display, f ...
in young people, and the risk of children taking it by accident. Many cultures have used cannabis for therapeutic purposes for thousands of years. Some American medical organizations have requested removal of cannabis from the list of
Schedule I controlled substance The Controlled Substances Act (CSA) is the statute establishing federal U.S. drug policy under which the manufacture, importation, possession, use, and distribution of certain substances is regulated. It was passed by the 91st United State ...
s, emphasizing that rescheduling would enable more extensive research and regulatory oversight to ensure safe access. Others oppose its legalization, such as the
American Academy of Pediatrics The American Academy of Pediatrics (AAP) is the largest professional association of pediatricians in the United States. It is headquartered in Itasca, Illinois, and maintains an office in Washington, D.C. The AAP has published hundreds of poli ...
. Medical cannabis can be administered through various methods, including capsules,
lozenge Lozenge or losange may refer to: * Lozenge (shape), a type of rhombus *Throat lozenge A throat lozenge (also known as a cough drop, sore throat sweet, troche, cachou, pastille or cough sweet) is a small, typically medicated tablet intended to ...
s,
tincture A tincture is typically an extract of plant or animal material dissolved in ethanol (ethyl alcohol). Solvent concentrations of 25–60% are common, but may run as high as 90%.Groot Handboek Geneeskrachtige Planten by Geert Verhelst In chemistr ...
s,
dermal patch A dermal patch or skin patch is a medicated adhesive patch placed on human skin to deliver a medication into the skin. This is in contrast to a transdermal patch, which delivers the medication through the skin and into the bloodstream. Popu ...
es, oral or dermal sprays,
cannabis edible A cannabis edible, also known as a cannabis-infused food or simply an edible, is a food item (either homemade or produced commercially) that contains decarboxylated cannabinoids (cannabinoid acids converted to their orally bioactive form) fro ...
s, and
vaporizing Vaporization (or vapo(u)risation) of an element or compound is a phase transition from the liquid phase to vapor. There are two types of vaporization: evaporation and boiling. Evaporation is a surface phenomenon, whereas boiling is a bulk phenomen ...
or smoking dried buds. Synthetic cannabinoids are available for prescription use in some countries, such as synthetic delta-9-THC and
nabilone Nabilone, sold under the brand name Cesamet among others, is a synthetic cannabinoid with therapeutic use as an antiemetic and as an adjunct analgesic for neuropathic pain. It mimics tetrahydrocannabinol (THC), the primary psychoactive compound ...
. Countries that allow the medical use of whole-plant cannabis include Argentina, Australia, Canada, Chile, Colombia, Germany, Greece, Israel, Italy, the Netherlands, Peru, Poland, Portugal, Spain, and Uruguay. In the United States, 38 states and the District of Columbia have legalized cannabis for medical purposes, beginning with the passage of California's
Proposition 215 Proposition 215, or the Compassionate Use Act of 1996, is a California law permitting the use of medical cannabis despite marijuana's lack of the normal Food and Drug Administration testing for safety and efficacy. It was enacted, on November ...
in 1996. Although cannabis remains prohibited for any use at the federal level, the
Rohrabacher–Farr amendment The Rohrabacher–Farr amendment (also known as the Rohrabacher–Blumenauer amendment) is legislation introduced by U.S. Representative Maurice Hinchey in 2001, prohibiting the Justice Department from spending funds to interfere with the impleme ...
was enacted in December 2014, limiting the ability of federal law to be enforced in states where medical cannabis has been legalized. This amendment reflects an increasing
bipartisan Bipartisanship, sometimes referred to as nonpartisanship, is a political situation, usually in the context of a two-party system (especially those of the United States and some other western countries), in which opposing Political party, politica ...
acknowledgment of the potential therapeutic uses of cannabis and the significance of state-level policymaking in this area.


Classification

In the U.S., the
National Institute on Drug Abuse The National Institute on Drug Abuse (NIDA) is a United States federal government research institute whose mission is to "advance science on the causes and consequences of drug use and addiction and to apply that knowledge to improve individual ...
defines medical cannabis as "using the whole, unprocessed marijuana plant or its basic extracts to treat symptoms of illness and other conditions". A cannabis plant includes more than 400 different chemicals, of which about 70 are
cannabinoid Cannabinoids () are several structural classes of compounds found primarily in the ''Cannabis'' plant or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoact ...
s. In comparison, typical government-approved medications contain only one or two chemicals. The number of active chemicals in cannabis is one reason why treatment with cannabis is difficult to classify and study. A 2014 review stated that the variations in ratio of CBD-to-THC in botanical and pharmaceutical preparations determines the therapeutic vs psychoactive effects (CBD attenuates THC's psychoactive effects) of cannabis products.


Medical uses

Overall, research into the health effects of medical cannabis has been of low quality and it is not clear whether it is a useful treatment for any condition, or whether harms outweigh any benefit. There is no consistent evidence that it helps with
chronic pain Chronic pain is pain that persists or recurs for longer than 3 months.https://icd.who.int/browse/2025-01/mms/en#1581976053 It is also known as gradual burning pain, electrical pain, throbbing pain, and nauseating pain. This type of pain is in cont ...
and
muscle spasms A spasm is a sudden involuntary contraction of a muscle, a group of muscles, or a hollow organ, such as the bladder. A spasmodic muscle contraction may be caused by many medical conditions, including dystonia. Most commonly, it is a musc ...
. Low quality evidence suggests its use for reducing
nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...
during
chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...
, improving appetite in
HIV/AIDS The HIV, human immunodeficiency virus (HIV) is a retrovirus that attacks the immune system. Without treatment, it can lead to a spectrum of conditions including acquired immunodeficiency syndrome (AIDS). It is a Preventive healthcare, pr ...
, improving sleep, and improving
tic A tic is a sudden and repetitive motor movement or vocalization that is not rhythmic and involves discrete muscle groups. Tics are typically brief and may resemble a normal behavioral characteristic or gesture. Tics can be invisible to the obs ...
s in
Tourette syndrome Tourette syndrome (TS), or simply Tourette's, is a common neurodevelopmental disorder that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) tic. Common tics are blinkin ...
. When usual treatments are ineffective,
cannabinoid Cannabinoids () are several structural classes of compounds found primarily in the ''Cannabis'' plant or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoact ...
s have also been recommended for
anorexia Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by Calorie restriction, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. Individuals wit ...
,
arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...
,
glaucoma Glaucoma is a group of eye diseases that can lead to damage of the optic nerve. The optic nerve transmits visual information from the eye to the brain. Glaucoma may cause vision loss if left untreated. It has been called the "silent thief of ...
, and
migraine Migraine (, ) is a complex neurological disorder characterized by episodes of moderate-to-severe headache, most often unilateral and generally associated with nausea, and light and sound sensitivity. Other characterizing symptoms may includ ...
. It is unclear whether American states might be able to mitigate the adverse effects of the
opioid epidemic The opioid epidemic, also referred to as the opioid crisis, is the rapid increase in the overuse, misuse or abuse, and overdose deaths attributed either in part or in whole to the class of drugs called opiates or opioids since the 1990s. It inc ...
by prescribing medical cannabis as an alternative pain management drug. Cannabis should not be used in
pregnancy Pregnancy is the time during which one or more offspring gestation, gestates inside a woman's uterus. A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Conception (biology), Conception usually occurs ...
.


Insomnia

Research analyzing data from the National Health and Nutrition Examination Survey (NHANES) did not find significant differences in sleep duration between cannabis users and non-users. This suggests that while some individuals may perceive benefits from cannabis use in terms of sleep, it may not significantly change overall sleep patterns across the general population. A review of literature up to 2018 indicates that cannabidiol (CBD) may have therapeutic potential for the treatment of insomnia. CBD, a non-psychoactive component of cannabis, is of particular interest due to its potential to influence sleep without the psychoactive effects associated with tetrahydrocannabinol (THC).


Nausea and vomiting

Medical cannabis is somewhat effective in
chemotherapy-induced nausea and vomiting Chemotherapy-induced nausea and vomiting (CINV) is a common side-effect of many cancer treatments. Nausea and vomiting are two of the most feared cancer treatment-related side effects for cancer patients and their families. In 1983, Coates et al. f ...
(CINV) and may be a reasonable option in those who do not improve following preferential treatment. Comparative studies have found cannabinoids to be more effective than some conventional antiemetics such as
prochlorperazine Prochlorperazine, formerly sold under the brand name Compazine among others, is a medication used to treat nausea, migraines, schizophrenia, psychosis and anxiety. It is a less preferred medication for anxiety. It may be taken by mouth, rectal ...
,
promethazine Promethazine, sold under the brand name Phenergan among others, is a first-generation antihistamine, sedative, and antiemetic used to treat allergies, insomnia, and nausea. It may also help with some symptoms associated with the common cold a ...
, and
metoclopramide Metoclopramide is a medication used to treat nausea, vomiting, gastroparesis, and gastroesophageal reflux disease. It is also used to treat migraine headaches. Common side effects include feeling tired, diarrhea, akathisia, and tardive dyski ...
in controlling CINV, but these are used less frequently because of side effects including dizziness, dysphoria, and hallucinations. Long-term cannabis use may cause nausea and vomiting, a condition known as
cannabinoid hyperemesis syndrome Cannabinoid hyperemesis syndrome (CHS) is recurrent nausea, vomiting, and cramping abdominal pain that can occur due to cannabis use. CHS is associated with frequent (weekly or more often), long-term (several months or longer) cannabis us ...
(CHS). A 2016
Cochrane review Cochrane is a British international charitable organisation formed to synthesize medical research findings to facilitate evidence-based choices about health interventions involving health professionals, patients and policy makers. It includes ...
said that cannabinoids were "probably effective" in treating chemotherapy-induced nausea in children, but with a high side-effect profile (mainly drowsiness, dizziness, altered moods, and increased appetite). Less common side effects were "ocular problems, orthostatic hypotension, muscle twitching, pruritus, vagueness, hallucinations, lightheadedness and dry mouth".


HIV/AIDS

Evidence is lacking for both efficacy and safety of cannabis and cannabinoids in treating patients with
HIV/AIDS The HIV, human immunodeficiency virus (HIV) is a retrovirus that attacks the immune system. Without treatment, it can lead to a spectrum of conditions including acquired immunodeficiency syndrome (AIDS). It is a Preventive healthcare, pr ...
or for
anorexia Anorexia nervosa (AN), often referred to simply as anorexia, is an eating disorder characterized by Calorie restriction, food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin. Individuals wit ...
associated with AIDS. As of 2013, current studies suffer from the effects of bias, small sample size, and lack of long-term data.


Pain

A 2021 review found little effect of using non-inhaled cannabis to relieve chronic pain. According to a 2019 systematic review, there have been inconsistent results of using cannabis for neuropathic pain, spasms associated with
multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...
and pain from
rheumatic Rheumatology () is a branch of medicine devoted to the diagnosis and management of disorders whose common feature is inflammation in the bones, muscles, joints, and internal organs. Rheumatology covers more than 100 different complex diseases, c ...
disorders, but was not effective treating chronic cancer pain. The authors state that additional
randomized controlled trials A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical ...
of different cannabis products are necessary to make conclusive recommendations. When cannabis is inhaled to relieve pain, blood levels of cannabinoids rise faster than when oral products are used, peaking within three minutes and attaining an analgesic effect in seven minutes. A 2011 review considered cannabis to be generally safe, and it appears safer than
opioid Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...
s in palliative care. A 2022 review concluded the pain relief experienced after using medical cannabis is due to the
placebo effect A placebo ( ) can be roughly defined as a sham medical treatment. Common placebos include inert tablets (like sugar pills), inert injections (like saline), sham surgery, and other procedures. Placebos are used in randomized clinical trials ...
, especially given widespread media attention that sets the expectation for pain relief.


Neurological conditions

Cannabis' efficacy is not clear in treating neurological problems, including
multiple sclerosis Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit ...
(MS) and movement problems. Evidence also suggests that oral cannabis extract is effective for reducing patient-centered measures of spasticity. A trial of cannabis is deemed to be a reasonable option if other treatments have not been effective. Its use for MS is approved in ten countries. A 2012 review found no problems with tolerance, abuse, or addiction. In the United States,
cannabidiol Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in ''Cannabis'', along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an anticonvulsant used to treat multiple f ...
, one of the cannabinoids found in the marijuana plant, has been approved for treating two severe forms of epilepsy, Lennox-Gastaut syndrome and
Dravet syndrome Dravet syndrome (DS), previously known as severe myoclonic epilepsy of infancy (SMEI), is an autosomal dominant genetic disorder which causes a catastrophic form of epilepsy, with prolonged seizures that are often triggered by hot temperatures o ...
.


Mental health

A 2019 systematic review found that there is a lack of evidence that cannabinoids are effective in treating depressive or
anxiety disorder Anxiety disorders are a group of mental disorders characterized by significant and uncontrollable feelings of anxiety and fear such that a person's social, occupational, and personal functions are significantly impaired. Anxiety may cause phys ...
s,
attention-deficit hyperactivity disorder Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterised by symptoms of inattention, hyperactivity, impulsivity, and emotional dysregulation that are excessive and pervasive, impairing in multiple con ...
(ADHD),
Tourette syndrome Tourette syndrome (TS), or simply Tourette's, is a common neurodevelopmental disorder that begins in childhood or adolescence. It is characterized by multiple movement (motor) tics and at least one vocal (phonic) tic. Common tics are blinkin ...
,
post-traumatic stress disorder Post-traumatic stress disorder (PTSD) is a mental disorder that develops from experiencing a Psychological trauma, traumatic event, such as sexual assault, domestic violence, child abuse, warfare and its associated traumas, natural disaster ...
, or
psychosis In psychopathology, psychosis is a condition in which a person is unable to distinguish, in their experience of life, between what is and is not real. Examples of psychotic symptoms are delusions, hallucinations, and disorganized or inco ...
. The relationship between cannabis use and
anxiety Anxiety is an emotion characterised by an unpleasant state of inner wikt:turmoil, turmoil and includes feelings of dread over Anticipation, anticipated events. Anxiety is different from fear in that fear is defined as the emotional response ...
symptoms is complex, and while some users report relief, the overall evidence from observational studies and clinical trials remains inconclusive. Cannabis use, especially at high doses, is associated with a higher risk of psychosis, particularly in individuals with a genetic predisposition to psychotic disorders like schizophrenia. Some studies have shown that cannabis can trigger a temporary psychotic episode, which may increase the risk of developing a psychotic disorder later. The impact of cannabis on depression is less clear. Some studies suggest a potential increase in depression risk among adolescents who use cannabis, though findings are inconsistent across studies.


Adverse effects


Medical use

There is insufficient data to draw strong conclusions about the safety of medical cannabis. Typically, adverse effects of medical cannabis use are not serious; they include tiredness, dizziness, increased appetite, and cardiovascular and psychoactive effects. Other effects can include impaired short-term memory; impaired motor coordination; altered judgment; and paranoia or psychosis at high doses. Tolerance to these effects develops over a period of days or weeks. The amount of cannabis normally used for medicinal purposes is not believed to cause any permanent cognitive impairment in adults, though long-term treatment in adolescents should be weighed carefully as they are more susceptible to these impairments. Withdrawal symptoms are rarely a problem with controlled medical administration of cannabinoids. The ability to drive vehicles or to operate machinery may be impaired until a tolerance is developed. Although supporters of medical cannabis say that it is safe, further research is required to assess the long-term safety of its use.


Cognitive effects

Recreational use of cannabis is associated with cognitive deficits, especially for those who begin to use cannabis in adolescence. there is a lack of research into long-term cognitive effects of medical use of cannabis, but one 12-month observational study reported that "MC patients demonstrated significant improvements on measures of
executive function In cognitive science and neuropsychology, executive functions (collectively referred to as executive function and cognitive control) are a set of cognitive processes that support goal-directed behavior, by regulating thoughts and actions thro ...
and clinical state over the course of 12 months".


Impact on psychosis

Exposure to THC can cause acute transient psychotic symptoms in healthy individuals and people with schizophrenia. A 2007 meta analysis concluded that cannabis use reduced the average age of onset of psychosis by 2.7 years relative to non-cannabis use. A 2005 meta analysis concluded that adolescent use of cannabis increases the risk of psychosis, and that the risk is dose-related. A 2004 literature review on the subject concluded that cannabis use is associated with a two-fold increase in the risk of psychosis, but that cannabis use is "neither necessary nor sufficient" to cause psychosis. A French review from 2009 came to a conclusion that cannabis use, particularly that before age 15, was a factor in the development of schizophrenic disorders.


Pharmacology

The
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''
Cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae that is widely accepted as being indigenous to and originating from the continent of Asia. However, the number of species is disputed, with as many as three species be ...
'' contains two species which produce useful amounts of psychoactive cannabinoids: ''
Cannabis indica ''Cannabis indica'' is an annual plant species in the family Cannabaceae indigenous to the Hindu Kush mountains of Southern Asia. The plant produces large amounts of tetrahydrocannabinol (THC) and tetrahydrocannabivarin (THCV), with total cann ...
'' and ''
Cannabis sativa ''Cannabis sativa'' is an annual Herbaceous plant, herbaceous flowering plant. The species was first classified by Carl Linnaeus in 1753. The specific epithet ''Sativum, sativa'' means 'cultivated'. Indigenous to East Asia, Eastern Asia, the pla ...
'', which are listed as Schedule I medicinal plants in the US; a third species, ''
Cannabis ruderalis ''Cannabis ruderalis'' is a Variety (botany), variety, subspecies, or species of ''Cannabis'' native to Central Europe, Central and Eastern Europe and Russia. It contains a relatively low quantity of psychoactive compound tetrahydrocannabinol ( ...
'', has few psychogenic properties. Cannabis contains more than 460 compounds; at least 80 of these are
cannabinoid Cannabinoids () are several structural classes of compounds found primarily in the ''Cannabis'' plant or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoact ...
s –
chemical compound A chemical compound is a chemical substance composed of many identical molecules (or molecular entities) containing atoms from more than one chemical element held together by chemical bonds. A molecule consisting of atoms of only one element ...
s that interact with
cannabinoid receptor Cannabinoid receptors, located throughout the body, are part of the endocannabinoid system of vertebrates a class of cell membrane receptors in the G protein-coupled receptor superfamily. As is typical of G protein-coupled receptors, the cann ...
s in the brain. As of 2012, more than 20 cannabinoids were being studied by the U.S. FDA. The most psychoactive cannabinoid found in the cannabis plant is
tetrahydrocannabinol Tetrahydrocannabinol (THC) is a cannabinoid found in cannabis. It is the principal psychoactive constituent of ''Cannabis'' and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) de ...
(or delta-9-tetrahydrocannabinol, commonly known as THC). Other cannabinoids include delta-8-tetrahydrocannabinol,
cannabidiol Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in ''Cannabis'', along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an anticonvulsant used to treat multiple f ...
(CBD),
cannabinol Cannabinol (CBN) is a mildly psychoactive phytocannabinoid that acts as a low affinity partial agonist at both CB1 and CB2 receptors. This activity at CB1 and CB2 receptors constitutes interaction of CBN with the endocannabinoid system (ECS) ...
(CBN),
cannabicyclol Cannabicyclol (CBL) is a non-psychoactive cannabinoid found in ''Cannabis''. CBL is a degradative product like cannabinol, with cannabichromene degrading into CBL through natural irradiation or under acid conditions. CBL is not scheduled under ...
(CBL),
cannabichromene Cannabichromene (CBC), also called cannabichrome, cannanbichromene, pentylcannabichromene or cannabinochromene, exhibits anti-inflammatory properties ''in vitro'', which may, theoretically, contribute to cannabis analgesic effects. It is a phytoca ...
(CBC) and
cannabigerol Cannabigerol (CBG) is a non-psychoactive cannabinoid and minor constituent of cannabis. It is one of more than 120identified cannabinoids found in the plant genus ''Cannabis''. The compound is the decarboxylated form of cannabigerolic acid (CBG ...
(CBG); they have less psychotropic effects than THC, but may play a role in the overall effect of cannabis. The most studied are THC, CBD and CBN. CB1 and CB2 are the primary cannabinoid receptors responsible for several of the effects of cannabinoids, although other receptors may play a role as well. Both belong to a group of receptors called G protein-coupled receptors (GPCRs). CB1 receptors are found in very high levels in the brain and are thought to be responsible for psychoactive effects. CB2 receptors are found peripherally throughout the body and are thought to modulate pain and inflammation.


Absorption

Cannabinoid absorption is dependent on its route of administration. Inhaled and vaporized THC have similar absorption profiles to smoked THC, with a
bioavailability In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. H ...
ranging from 10 to 35%. Oral administration has the lowest bioavailability of approximately 6%, variable absorption depending on the vehicle used, and the longest time to peak plasma levels (2 to 6 hours) compared to smoked or vaporized THC. Similar to THC, CBD has poor oral bioavailability, approximately 6%. The low bioavailability is largely attributed to significant first-pass metabolism in the liver and erratic absorption from the gastrointestinal tract. However, oral administration of CBD has a faster time to peak concentrations (2 hours) than THC. Due to the poor bioavailability of oral preparations, alternative routes of administration have been studied, including sublingual and rectal. These alternative formulations maximize bioavailability and reduce first-pass metabolism. Sublingual administration in rabbits yielded bioavailability of 16% and time to peak concentration of 4 hours. Rectal administration in monkeys doubled bioavailability to 13.5% and achieved peak blood concentrations within 1 to 8 hours after administration.


Distribution

Like cannabinoid absorption, distribution is also dependent on route of administration. Smoking and inhalation of vaporized cannabis have better absorption than do other routes of administration, and therefore also have more predictable distribution. THC is highly protein bound once absorbed, with only 3% found unbound in the plasma. It distributes rapidly to highly vascularized organs such as the heart, lungs, liver, spleen, and kidneys, as well as to various glands. Low levels can be detected in the brain, testes, and unborn fetuses, all of which are protected from systemic circulation via barriers. THC further distributes into fatty tissues a few days after administration due to its high lipophilicity, and is found deposited in the spleen and fat after redistribution.


Metabolism

Delta-9-THC is the primary molecule responsible for the effects of cannabis. Delta-9-THC is metabolized in the liver and turns into 11-OH-THC. 11-OH-THC is the first metabolic product in this pathway. Both Delta-9-THC and 11-OH-THC are psychoactive. The metabolism of THC into 11-OH-THC plays a part in the heightened psychoactive effects of edible cannabis. Next, 11-OH-THC is metabolized in the liver into 11-COOH-THC, which is the second metabolic product of THC. 11-COOH-THC is not psychoactive. Ingestion of edible cannabis products lead to a slower onset of effect than the inhalation of it because the THC travels to the liver first through the blood before it travels to the rest of the body. Inhaled cannabis can result in THC going directly to the brain, where it then travels from the brain back to the liver in recirculation for metabolism. Eventually, both routes of metabolism result in the metabolism of psychoactive THC to inactive 11-COOH-THC.


Excretion

Due to substantial metabolism of THC and CBD, their metabolites are excreted mostly via
feces Feces (also known as faeces American and British English spelling differences#ae and oe, or fæces; : faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the ...
, rather than by urine. After delta-9-THC is hydroxylated into 11-OH-THC via CYP2C9, CYP2C19, and CYP3A4, it undergoes phase II metabolism into more than 30 metabolites, a majority of which are products of
glucuronidation Glucuronidation is often involved in drug metabolism of substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids. These linkages involve gly ...
. Approximately 65% of THC is excreted in feces and 25% in the urine, while the remaining 10% is excreted by other means. The terminal half-life of THC is 25 to 36 hours, whereas for CBD it is 18 to 32 hours. CBD is hydroxylated by P450 liver enzymes into 7-OH-CBD. Its metabolites are products of primarily CYP2C19 and CYP3A4 activity, with potential activity of CYP1A1, CYP1A2, CYP2C9, and CYP2D6. Similar to delta-9-THC, a majority of CBD is excreted in feces and some in the urine. The terminal half-life is approximately 18–32 hours.


Administration

Smoking Smoking is a practice in which a substance is combusted, and the resulting smoke is typically inhaled to be tasted and absorbed into the bloodstream of a person. Most commonly, the substance used is the dried leaves of the tobacco plant, whi ...
has been the means of administration of cannabis for many users, but it is not suitable for the use of cannabis as a medicine. It was the most common method of medical cannabis consumption in the US . It is difficult to predict the pharmacological response to cannabis because concentration of cannabinoids varies widely, as there are different ways of preparing it for consumption (smoked, applied as oils, eaten, infused into other foods, or drunk) and a lack of production controls. The potential for adverse effects from smoke inhalation makes smoking a less viable option than oral preparations. Cannabis vaporizers have gained popularity because of a perception among users that fewer harmful chemicals are ingested when components are inhaled via aerosol rather than smoke. Cannabinoid medicines are available in pill form (
dronabinol Dronabinol (), sold under the brand names Marinol and Syndros, is the generic name for the molecule of (−)-trans-Δ9-tetrahydrocannabinol (THC) in the pharmaceutical context. It has indications as an appetite stimulant, antiemetic, and sleep ...
and
nabilone Nabilone, sold under the brand name Cesamet among others, is a synthetic cannabinoid with therapeutic use as an antiemetic and as an adjunct analgesic for neuropathic pain. It mimics tetrahydrocannabinol (THC), the primary psychoactive compound ...
) and liquid extracts formulated into an oromucosal spray (
nabiximols Nabiximols ( USAN), sold under the brand name Sativex, is a specific ''Cannabis'' extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticit ...
). Oral preparations are "problematic due to the uptake of cannabinoids into fatty tissue, from which they are released slowly, and the significant first-pass liver metabolism, which breaks down Δ9THC and contributes further to the variability of plasma concentrations". The US Food and Drug Administration (FDA) has not approved smoked cannabis for any condition or disease, as it deems that evidence is lacking concerning safety and efficacy. The FDA issued a 2006 advisory against ''smoked'' medical cannabis stating: "marijuana has a high potential for abuse, has no currently accepted medical use in treatment in the United States, and has a lack of accepted safety for use under medical supervision."


History


Ancient

Cannabis, called ''má''
Radical 200 or radical hemp () meaning "hemp" or "flax" is one of the 6 Kangxi radicals (214 radicals in total) composed of 11 strokes. Historically, it is the Chinese word for cannabis. In the ''Kangxi Dictionary'', there are 34 characters (out ...
(meaning "hemp; cannabis; numbness") or ''dàmá'' 大麻 (with "big; great") in Chinese, was used in
Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
for fiber starting about 10,000 years ago. The botanist
Hui-lin Li Hui-lin Li (李惠林, 1911–2002) was a Chinese botanist, academic, and researcher who worked at the University of Pennsylvania, National Taiwan University, and Chinese Academy of Sciences. Biography Hui-lin Li was born in Soochow, a city clos ...
wrote that in China, "The use of Cannabis in medicine was probably a very early development. Since ancient humans used hemp seed as food, it was quite natural for them to also discover the medicinal properties of the plant." Emperor
Shen-Nung Shennong ( zh, c=神農, p=Shénnóng), variously translated as "Divine Farmer" or "Divine Husbandman", born , was a mythological Chinese ruler known as the first Yan Emperor who has become a deity in Chinese and Vietnamese folk religion. He ...
, who was also a pharmacologist, wrote a book on treatment methods in 2737 BCE that included the medical benefits of cannabis. He recommended the substance for many ailments, including constipation, gout, rheumatism, and absent-mindedness. Cannabis is one of the 50 "fundamental" herbs in
traditional Chinese medicine Traditional Chinese medicine (TCM) is an alternative medicine, alternative medical practice drawn from traditional medicine in China. A large share of its claims are pseudoscientific, with the majority of treatments having no robust evidence ...
. The
Ebers Papyrus The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus of herbal knowledge dating to (the late Second Intermediate Period or early New Kingdom). Among the oldest and most important medical papyri of Ancient Egypt, it ...
() from
Ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...
describes medical cannabis. The ancient Egyptians used hemp (cannabis) in
suppositories A suppository is a dosage form used to deliver pharmaceutical drug, medications by insertion into a body orifice (any opening in the body), where it dissolves or melts to exert local or systemic effects. There are three types of suppositories, eac ...
for relieving the pain of
hemorrhoid Hemorrhoids (or haemorrhoids), also known as piles, are vascular structures in the anal canal. In their normal state, they are cushions that help with stool control. They become a disease when swollen or inflamed; the unqualified term ''h ...
s. Surviving texts from
ancient India Anatomically modern humans first arrived on the Indian subcontinent between 73,000 and 55,000 years ago. The earliest known human remains in South Asia date to 30,000 years ago. Sedentism, Sedentariness began in South Asia around 7000 BCE; ...
confirm that cannabis' psychoactive properties were recognized, and doctors used it for treating a variety of illnesses and ailments, including insomnia, headaches, gastrointestinal disorders, and pain, including during childbirth. The
Ancient Greeks Ancient Greece () was a northeastern Mediterranean civilization, existing from the Greek Dark Ages of the 12th–9th centuries BC to the end of classical antiquity (), that comprised a loose collection of culturally and linguistically re ...
used cannabis to dress wounds and sores on their horses, and in humans, dried leaves of cannabis were used to treat nose bleeds, and cannabis seeds were used to expel tapeworms. In the
medieval Islamic world In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and t ...
, Arabic physicians made use of the
diuretic A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics ...
,
antiemetic An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They may ...
,
antiepileptic Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatmen ...
,
anti-inflammatory Anti-inflammatory is the property of a substance or treatment that reduces inflammation, fever or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs reduce pain by inhibiting mechan ...
,
analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...
and
antipyretic An antipyretic (, from ''anti-'' 'against' and ' 'feverish') is a substance that reduces fever. Antipyretics cause the hypothalamus to override a prostaglandin-induced increase in temperature. The body then works to lower the temperature, which r ...
properties of ''
Cannabis sativa ''Cannabis sativa'' is an annual Herbaceous plant, herbaceous flowering plant. The species was first classified by Carl Linnaeus in 1753. The specific epithet ''Sativum, sativa'' means 'cultivated'. Indigenous to East Asia, Eastern Asia, the pla ...
'', and used it extensively as medication from the 8th to 18th centuries.


Landrace strains

Cannabis seeds may have been used for food, rituals or religious practices in ancient Europe and China. Harvesting the plant led to the spread of cannabis throughout
Eurasia Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...
about 10,000 to 5,000 years ago, with further distribution to the
Middle East The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq. The term came into widespread usage by the United Kingdom and western Eur ...
and Africa about 2,000 to 500 years ago. A
landrace A landrace is a Domestication, domesticated, locally adapted, often traditional variety of a species of animal or plant that has developed over time, through adaptation to its natural and cultural Environment (biophysical), environment of agric ...
strain of cannabis developed over centuries. They are cultivars of the plant that originated in one specific region. Widely cultivated strains of cannabis, such as "Afghani" or "Hindu Kush", are indigenous to the
Pakistan Pakistan, officially the Islamic Republic of Pakistan, is a country in South Asia. It is the List of countries and dependencies by population, fifth-most populous country, with a population of over 241.5 million, having the Islam by country# ...
and
Afghanistan Afghanistan, officially the Islamic Emirate of Afghanistan, is a landlocked country located at the crossroads of Central Asia and South Asia. It is bordered by Pakistan to the Durand Line, east and south, Iran to the Afghanistan–Iran borde ...
regions, while "Durban Poison" is native to Africa. There are approximately 16 landrace strains of cannabis identified from Pakistan, Jamaica, Africa, Mexico, Central America and Asia.


Modern

An Irish physician,
William Brooke O'Shaughnessy Sir William Brooke O'Shaughnessy (from 1861 as William O'Shaughnessy Brooke) (October 1809 – 8 January 1889) was an Irish physician famous for his wide-ranging scientific work in pharmacology, chemistry, and inventions related to telegraphy an ...
, is credited with introducing cannabis to Western medicine. O'Shaughnessy discovered cannabis in the 1830s while living abroad in
India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
, where he conducted numerous experiments investigating the drug's medical utility (noting in particular its
analgesic An analgesic drug, also called simply an analgesic, antalgic, pain reliever, or painkiller, is any member of the group of drugs used for pain management. Analgesics are conceptually distinct from anesthetics, which temporarily reduce, and in s ...
and
anticonvulsant Anticonvulsants (also known as antiepileptic drugs, antiseizure drugs, or anti-seizure medications (ASM)) are a diverse group of pharmacological agents used in the treatment of epileptic seizures. Anticonvulsants are also used in the treatme ...
effects). He returned to
England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...
with a supply of cannabis in 1842, after which its use spread through Europe and the United States. In 1845 French physician
Jacques-Joseph Moreau Jacques-Joseph Moreau (3 June 1804 – 26 June 1884), nicknamed "Moreau de Tours", was a French psychiatrist and member of the Club des Hashischins. Moreau was the first physician to do systematic work on drugs' effects on the central nervous ...
published a book about the use of cannabis in psychiatry. In 1850 cannabis was entered into the
United States Pharmacopeia The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the over 200-year old United States Pharmacopeial Convention (usually also called the USP), a nonprofi ...
. An anecdotal report of ''
Cannabis indica ''Cannabis indica'' is an annual plant species in the family Cannabaceae indigenous to the Hindu Kush mountains of Southern Asia. The plant produces large amounts of tetrahydrocannabinol (THC) and tetrahydrocannabivarin (THCV), with total cann ...
'' as a treatment for
tetanus Tetanus (), also known as lockjaw, is a bacterial infection caused by ''Clostridium tetani'' and characterized by muscle spasms. In the most common type, the spasms begin in the jaw and then progress to the rest of the body. Each spasm usually l ...
appeared in
Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...
in 1880. The use of cannabis in medicine began to decline by the end of the 19th century, due to difficulty in controlling dosages and the rise in popularity of synthetic and
opium Opium (also known as poppy tears, or Lachryma papaveris) is the dried latex obtained from the seed Capsule (fruit), capsules of the opium poppy ''Papaver somniferum''. Approximately 12 percent of opium is made up of the analgesic alkaloid mor ...
-derived drugs. Also, the advent of the hypodermic
syringe A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside ...
allowed these drugs to be injected for immediate effect, in contrast to cannabis which is not water-soluble and therefore cannot be injected. In the United States, the medical use of cannabis further declined with the passage of the
Marihuana Tax Act of 1937 The Marihuana Tax Act of 1937, , was a United States Act that placed a tax on the sale of Cannabis (drug), cannabis. The H.R. 6385 act was drafted by Harry Anslinger and introduced by Rep. Robert L. Doughton of North Carolina, on April 14, 1937. ...
, which imposed new regulations and fees on physicians prescribing cannabis. Cannabis was removed from the U.S. Pharmacopeia in 1941, and officially banned for any use with the passage of the
Controlled Substances Act The Controlled Substances Act (CSA) is the statute establishing federal government of the United States, federal drug policy of the United States, U.S. drug policy under which the manufacture, importation, possession, use, and distribution of ...
of 1970. Cannabis began to attract renewed interest as medicine in the 1970s and 1980s, in particular due to its use by cancer and AIDS patients who reported relief from the effects of
chemotherapy Chemotherapy (often abbreviated chemo, sometimes CTX and CTx) is the type of cancer treatment that uses one or more anti-cancer drugs (list of chemotherapeutic agents, chemotherapeutic agents or alkylating agents) in a standard chemotherapy re ...
and
wasting syndrome Cachexia () is a syndrome that happens when people have certain illnesses, causing muscle loss that cannot be fully reversed with improved nutrition. It is most common in diseases like cancer, congestive heart failure, chronic obstructive pulm ...
. In 1996,
California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
became the first U.S. state to legalize medical cannabis in defiance of federal law. In 2001,
Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
became the first country to adopt a system regulating the medical use of cannabis. File:Da-ma.png, The use of cannabis, at least as fiber, has been shown to go back at least 10,000 years in
Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...
. "Dà má" (
Pinyin Hanyu Pinyin, or simply pinyin, officially the Chinese Phonetic Alphabet, is the most common romanization system for Standard Chinese. ''Hanyu'' () literally means 'Han Chinese, Han language'—that is, the Chinese language—while ''pinyin' ...
pronunciation) is the Chinese expression for cannabis, the first character meaning "big" and the second character meaning "hemp". File:Drug bottle containing cannabis.jpg, ''Cannabis indica'' fluid extract, American Druggists Syndicate, pre-1937 File:CannabisAmericana JLHopkins B.jpg, An advertisement for ''cannabis americana'' distributed by a pharmacist in New York in 1917 File:PEbers c41-bc.jpg, The
Ebers Papyrus The Ebers Papyrus, also known as Papyrus Ebers, is an Egyptian medical papyrus of herbal knowledge dating to (the late Second Intermediate Period or early New Kingdom). Among the oldest and most important medical papyri of Ancient Egypt, it ...
() from Ancient Egypt has a prescription for medical marijuana applied directly for inflammation.


Society and culture


Legal status

Countries that have legalized the medical use of cannabis include
Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...
,
Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
,
Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...
,
Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...
,
Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...
,
Colombia Colombia, officially the Republic of Colombia, is a country primarily located in South America with Insular region of Colombia, insular regions in North America. The Colombian mainland is bordered by the Caribbean Sea to the north, Venezuel ...
,
Costa Rica Costa Rica, officially the Republic of Costa Rica, is a country in Central America. It borders Nicaragua to the north, the Caribbean Sea to the northeast, Panama to the southeast, and the Pacific Ocean to the southwest, as well as Maritime bo ...
,
Croatia Croatia, officially the Republic of Croatia, is a country in Central Europe, Central and Southeast Europe, on the coast of the Adriatic Sea. It borders Slovenia to the northwest, Hungary to the northeast, Serbia to the east, Bosnia and Herze ...
,
Cyprus Cyprus (), officially the Republic of Cyprus, is an island country in the eastern Mediterranean Sea. Situated in West Asia, its cultural identity and geopolitical orientation are overwhelmingly Southeast European. Cyprus is the List of isl ...
,
Czech Republic The Czech Republic, also known as Czechia, and historically known as Bohemia, is a landlocked country in Central Europe. The country is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the south ...
,
Finland Finland, officially the Republic of Finland, is a Nordic country in Northern Europe. It borders Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland to the south, ...
,
Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...
,
Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...
,
Israel Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...
,
Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
,
Jamaica Jamaica is an island country in the Caribbean Sea and the West Indies. At , it is the third-largest island—after Cuba and Hispaniola—of the Greater Antilles and the Caribbean. Jamaica lies about south of Cuba, west of Hispaniola (the is ...
,
Lebanon Lebanon, officially the Republic of Lebanon, is a country in the Levant region of West Asia. Situated at the crossroads of the Mediterranean Basin and the Arabian Peninsula, it is bordered by Syria to the north and east, Israel to the south ...
,
Luxembourg Luxembourg, officially the Grand Duchy of Luxembourg, is a landlocked country in Western Europe. It is bordered by Belgium to the west and north, Germany to the east, and France on the south. Its capital and most populous city, Luxembour ...
,
Malta Malta, officially the Republic of Malta, is an island country in Southern Europe located in the Mediterranean Sea, between Sicily and North Africa. It consists of an archipelago south of Italy, east of Tunisia, and north of Libya. The two ...
,
Morocco Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...
, the
Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...
,
New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...
,
North Macedonia North Macedonia, officially the Republic of North Macedonia, is a landlocked country in Southeast Europe. It shares land borders with Greece to the south, Albania to the west, Bulgaria to the east, Kosovo to the northwest and Serbia to the n ...
,
Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...
,
Peru Peru, officially the Republic of Peru, is a country in western South America. It is bordered in the north by Ecuador and Colombia, in the east by Brazil, in the southeast by Bolivia, in the south by Chile, and in the south and west by the Pac ...
,
Poland Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...
,
Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...
,
Rwanda Rwanda, officially the Republic of Rwanda, is a landlocked country in the Great Rift Valley of East Africa, where the African Great Lakes region and Southeast Africa converge. Located a few degrees south of the Equator, Rwanda is bordered by ...
,
Sri Lanka Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, also known historically as Ceylon, is an island country in South Asia. It lies in the Indian Ocean, southwest of the Bay of Bengal, separated from the Indian subcontinent, ...
,
Switzerland Switzerland, officially the Swiss Confederation, is a landlocked country located in west-central Europe. It is bordered by Italy to the south, France to the west, Germany to the north, and Austria and Liechtenstein to the east. Switzerland ...
,
Thailand Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...
, the
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
, and
Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...
. Other countries have more restrictive laws that allow only the use of isolated cannabinoid drugs such as
Sativex Nabiximols ( USAN), sold under the brand name Sativex, is a specific ''Cannabis'' extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticit ...
or
Epidiolex Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in ''Cannabis'', along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an anticonvulsant used to treat multiple f ...
. Countries with the most relaxed policies include Canada, the Netherlands, Thailand, and Uruguay, where cannabis can be purchased without need for a prescription. In
Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
, THC content of medical cannabis is limited to one percent. In the
United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...
, the legality of medical cannabis varies by state. However, in many of these countries, access may not always be possible under the same conditions.


International law

Cannabis and its derivatives are subject to regulation under three
United Nations The United Nations (UN) is the Earth, global intergovernmental organization established by the signing of the Charter of the United Nations, UN Charter on 26 June 1945 with the stated purpose of maintaining international peace and internationa ...
drug control treaties: the 1961
Single Convention on Narcotic Drugs The Single Convention on Narcotic Drugs, 1961 (Single Convention, 1961 Convention, or C61) is an international treaty that controls activities (cultivation, production, supply, trade, transport) involving specific narcotic drugs and lays down a ...
, the 1971
Convention on Psychotropic Substances The Convention on Psychotropic Substances of 1971 is a United Nations treaty designed to control psychoactive drugs such as amphetamine-type stimulants, barbiturates, benzodiazepines, and psychedelics signed in Vienna, Austria on 21 February ...
, and the 1988 Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances. Cannabis and cannabis resin are classified as a Schedule I drug under the Single Convention treaty, meaning that medical use is considered "indispensible for the relief of pain and suffering" but that it is considered to be an addictive medication with risks of abuse. Countries have an obligation to provide access and sufficient availability of drugs listed in Schedule I for the purposes of medical uses. Prior to December 2020 cannabis and cannabis resin were also included in Schedule IV, a more restrictive level of control, which is for only the most dangerous drugs such as heroin and fentanyl. They were removed after an independent scientific assessment by the
World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...
in 2018-1029. Member nations of the UN Commission on Narcotic Drugs voted 27–25 to remove it from Schedule IV on 2 December 2020, following a
World Health Organization The World Health Organization (WHO) is a list of specialized agencies of the United Nations, specialized agency of the United Nations which coordinates responses to international public health issues and emergencies. It is headquartered in Gen ...
recommendation for removal in January 2019.


United States

In the United States, the use of cannabis for medical purposes is legal in 38 states, four out of five permanently inhabited
U.S. territories Territories of the United States are sub-national administrative divisions and dependent territories overseen by the federal government of the United States. The American territories differ from the U.S. states and Indian reservations in th ...
, and the
District of Columbia Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and Federal district of the United States, federal district of the United States. The city is on the Potomac River, across from ...
. An additional 10 states have more restrictive laws allowing the use of low-THC products. Cannabis remains illegal at the federal level under the
Controlled Substances Act The Controlled Substances Act (CSA) is the statute establishing federal government of the United States, federal drug policy of the United States, U.S. drug policy under which the manufacture, importation, possession, use, and distribution of ...
, which classifies it as a Schedule I drug with a high potential for abuse and no accepted medical use. In December 2014, however, the
Rohrabacher–Farr amendment The Rohrabacher–Farr amendment (also known as the Rohrabacher–Blumenauer amendment) is legislation introduced by U.S. Representative Maurice Hinchey in 2001, prohibiting the Justice Department from spending funds to interfere with the impleme ...
was signed into law, prohibiting the
Justice Department A justice ministry, ministry of justice, or department of justice, is a ministry or other government agency in charge of the administration of justice. The ministry or department is often headed by a minister of justice (minister for justice in a ...
from prosecuting individuals acting in accordance with state medical cannabis laws. In the US, the FDA has approved two oral cannabinoids for use as medicine in 1985:
dronabinol Dronabinol (), sold under the brand names Marinol and Syndros, is the generic name for the molecule of (−)-trans-Δ9-tetrahydrocannabinol (THC) in the pharmaceutical context. It has indications as an appetite stimulant, antiemetic, and sleep ...
(pure delta-9-THC; brand name Marinol) and
nabilone Nabilone, sold under the brand name Cesamet among others, is a synthetic cannabinoid with therapeutic use as an antiemetic and as an adjunct analgesic for neuropathic pain. It mimics tetrahydrocannabinol (THC), the primary psychoactive compound ...
(a synthetic neocannabinoid; brand name Cesamet). In the US, they are both listed as Schedule II, indicating high potential for side effects and addiction.


Economics


Distribution

The method of obtaining medical cannabis varies by region and by legislation. In the US, most consumers grow their own or buy it from
cannabis dispensaries Cannabis dispensaries in the United States or marijuana dispensaries are a type of cannabis retail outlet, local government-regulated physical location, typically inside a retail storefront or office building, in which a person can purchase can ...
in states where it is legal. Marijuana vending machines for selling or dispensing cannabis are in use in the United States and are planned to be used in Canada. In 2014, the startup Meadow began offering on-demand delivery of medical marijuana in the San Francisco Bay Area, through their mobile app. Almost 70% of medical cannabis is exported from the United Kingdom, according to a 2017 United Nations report, with much of the remaining amount coming from Canada and the Netherlands.


Insurance

In the United States, health insurance companies may not pay for a medical marijuana prescription as the
Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respo ...
must approve any substance for medicinal purposes. Before this can happen, the FDA must first permit the study of the medical benefits and drawbacks of the substance, which it has not done since it was placed on Schedule I of the Controlled Substances Act in 1970. Therefore, all expenses incurred fulfilling a medical marijuana prescription will possibly be incurred as out-of-pocket. However, the
New Mexico Court of Appeals The New Mexico Court of Appeals (in case citation, N.M. Ct. App.) is the intermediate-level appellate court for the state of New Mexico. History The court of appeals was created by a constitutional amendment submitted to the electorate in a ...
has ruled that
workers' compensation Workers' compensation or workers' comp is a form of insurance providing wage replacement and medical benefits to employees injured in the course of employment in exchange for mandatory relinquishment of the employee's right to sue his or her emp ...
insurance must pay for prescribed marijuana as part of the state's Medical Cannabis Program.


Positions of medical organizations

Medical organizations that have issued statements in support of allowing access to medical cannabis include the
American Nurses Association The American Nurses Association (ANA) is a 501(c)(6) professional organization to advance and protect the profession of nursing. It started in 1896 as the Nurses Associated Alumnae and was renamed the American Nurses Association in 1911. It is b ...
,
American Public Health Association The American Public Health Association (APHA) is a Washington, D.C.–based professional membership and advocacy organization for public health professionals in the United States. APHA is the largest professional organization of public health pr ...
,
American Medical Student Association The American Medical Student Association (AMSA), founded in 1950 and based in Washington, D.C., is an independent association of physicians-in-training in the United States. AMSA is a student-governed national organization. They have a membershi ...
,
National Multiple Sclerosis Society The National Multiple Sclerosis Society (NMSS) is an American nonprofit organization founded in 1946. It is an organization dedicated to supporting individuals affected by multiple sclerosis (MS) and funding research to find a cure for the diseas ...
,
Epilepsy Foundation The Epilepsy Foundation, also Epilepsy Foundation of America (EFA), is a non-profit national foundation, headquartered in Bowie, Maryland, dedicated to the welfare of people with epilepsy and seizure disorders. The foundation was established in 196 ...
, and
Leukemia & Lymphoma Society The Leukemia & Lymphoma Society (LLS), a 501(c)(3) charitable organization founded in 1949, is a voluntary health organization dedicated to fighting blood cancer world-wide. LLS funds blood cancer research on cures for leukemia, lymphoma, Hodgkin ...
. Organizations that oppose the legalization of medical cannabis include the
American Academy of Pediatrics The American Academy of Pediatrics (AAP) is the largest professional association of pediatricians in the United States. It is headquartered in Itasca, Illinois, and maintains an office in Washington, D.C. The AAP has published hundreds of poli ...
(AAP) and
American Psychiatric Association The American Psychiatric Association (APA) is the main professional organization of psychiatrists and trainee psychiatrists in the United States, and the largest psychiatric organization in the world. It has more than 39,200 members who are in ...
. However, the AAP also supports rescheduling for the purpose of facilitating research. The
American Medical Association The American Medical Association (AMA) is an American professional association and lobbying group of physicians and medical students. This medical association was founded in 1847 and is headquartered in Chicago, Illinois. Membership was 271,660 ...
and
American College of Physicians The American College of Physicians (ACP) is a Philadelphia-based national organization of internal medicine physicians, who specialize in the diagnosis, treatment, and care of adults. With 161,000 members, ACP is the largest medical-specialty or ...
do not take a position on the legalization of medical cannabis, but have called for the Schedule I classification to be reviewed. The
American Academy of Family Physicians The American Academy of Family Physicians (AAFP) was founded in 1947 to promote and maintain high-quality standards for family medicine, an offshoot of the classical general practitioner. It is headquartered in Leawood, Kansas. AAFP is one of ...
and
American Society of Addiction Medicine The American Society of Addiction Medicine (ASAM), founded in 1954, is a professional medical society representing over 7,000 physicians, clinicians, and associated professionals in the field of addiction medicine. ASAM is dedicated to increasin ...
also do not take a position, but do support rescheduling to better facilitate research. The
American Heart Association The American Heart Association (AHA) is a nonprofit organization in the United States that funds cardiovascular medical research, educates consumers on healthy living and fosters appropriate Heart, cardiac care in an effort to reduce disability ...
says that "many of the concerning health implications of cannabis include cardiovascular diseases" but that it supports rescheduling to allow "more nuanced ... marijuana legislation and regulation" and to "reflect the existing science behind cannabis". The
American Cancer Society The American Cancer Society (ACS) is a nationwide non-profit organization dedicated to eliminating cancer. The ACS publishes the journals ''Cancer'', '' CA: A Cancer Journal for Clinicians'' and '' Cancer Cytopathology''. History The society w ...
and
American Psychological Association The American Psychological Association (APA) is the main professional organization of psychologists in the United States, and the largest psychological association in the world. It has over 170,000 members, including scientists, educators, clin ...
have noted the obstacles that exist for conducting research on cannabis, and have called on the federal government to better enable scientific study of the drug.
Cancer Research UK Cancer Research UK (CRUK) is the world's largest independent cancer research organisation. It is registered as a charity in the United Kingdom and Isle of Man, and was formed on 4 February 2002 by the merger of The Cancer Research Campaign and t ...
say that while cannabis is being studied for therapeutic potential, "claims that there is solid "proof" that cannabis or cannabinoids can cure cancer is highly misleading to patients and their families, and builds a false picture of the state of progress in this area".


Nonproprietary names

There are three International Nonproprietary Name (INN) granted for cannabinoids: two plant-derived
phytocannabinoids Cannabinoids () are several structural classes of compounds found primarily in the ''Cannabis'' plant or as synthetic compounds. The most notable cannabinoid is the phytocannabinoid tetrahydrocannabinol (THC) (delta-9-THC), the primary psychoact ...
and one
neocannabinoid Synthetic cannabinoids, or neocannabinoids, are a class of designer drug molecules that bind to the same receptors to which cannabinoids ( THC, CBD and many others) in cannabis plants attach. These novel psychoactive substances should not be co ...
: *
Dronabinol Dronabinol (), sold under the brand names Marinol and Syndros, is the generic name for the molecule of (−)-trans-Δ9-tetrahydrocannabinol (THC) in the pharmaceutical context. It has indications as an appetite stimulant, antiemetic, and sleep ...
is the INN for delta-9-THC (there is a common confusion according to which the word "dronabinol" would only refer to synthetic delta-9-THC, which is incorrect). *
Cannabidiol Cannabidiol (CBD) is a phytocannabinoid, one of 113 identified cannabinoids in ''Cannabis'', along with tetrahydrocannabinol (THC), and accounts for up to 40% of the plant's extract. Medically, it is an anticonvulsant used to treat multiple f ...
is also the official INN for the molecule, granted in 2017. *
Nabilone Nabilone, sold under the brand name Cesamet among others, is a synthetic cannabinoid with therapeutic use as an antiemetic and as an adjunct analgesic for neuropathic pain. It mimics tetrahydrocannabinol (THC), the primary psychoactive compound ...
is the INN for a synthetic cannabinoid analog (not present in ''
Cannabis ''Cannabis'' () is a genus of flowering plants in the family Cannabaceae that is widely accepted as being indigenous to and originating from the continent of Asia. However, the number of species is disputed, with as many as three species be ...
'' plants).
Nabiximols Nabiximols ( USAN), sold under the brand name Sativex, is a specific ''Cannabis'' extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticit ...
is the generic name (but not recognized as an INN) of a mixture of Cannabidiol and Dronabinol. Its most common form is the oromucosal spray derived from two strains of ''Cannabis sativa'' and containing THC and CBD traded under the brand name Sativex®. It is not approved in the United States, but is approved in several European countries, Canada, and New Zealand as of 2013. As an
antiemetic An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer. They may ...
, these medications are usually used when conventional treatment for nausea and vomiting associated with cancer chemotherapy fail to work.
Nabiximols Nabiximols ( USAN), sold under the brand name Sativex, is a specific ''Cannabis'' extract that was approved in 2010 as a botanical drug in the United Kingdom. Nabiximols is sold as a mouth spray intended to alleviate neuropathic pain, spasticit ...
is used for treatment of spasticity associated with MS when other therapies have not worked, and when an initial trial demonstrates "meaningful improvement". Trials for FDA approval in the US are underway. It is also approved in several European countries for overactive bladder and
vomiting Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...
. When sold under the trade name Sativex as a mouth spray, the prescribed daily dose in Sweden delivers a maximum of 32.4 mg of
THC Tetrahydrocannabinol (THC) is a cannabinoid found in cannabis. It is the principal psychoactive constituent of ''Cannabis'' and one of at least 113 total cannabinoids identified on the plant. Although the chemical formula for THC (C21H30O2) de ...
and 30 mg of CBD; mild to moderate dizziness is common during the first few weeks. Relative to inhaled consumption, peak concentration of oral THC is delayed, and it may be difficult to determine optimal dosage because of variability in patient absorption. In 1964, Albert Lockhart and
Manley West Manley Elisha West OM (17 March 1929 – 24 April 2012) was a Jamaican pharmacologist who studied the marijuana plant. He investigated medicines for glaucoma. Education West was born in Fairy Hill, Portland Parish, Jamaica. He studied at Titc ...
began studying the health effects of traditional cannabis use in Jamaican communities. They developed, and in 1987 gained permission to market, the pharmaceutical "Canasol", one of the first cannabis extracts.


Research

A 2022 review concluded that "oral, synthetic cannabis products with high THC-to-CBD ratios and sublingual, extracted cannabis products with comparable THC-to-CBD ratios may be associated with short-term improvements in chronic pain and increased risk for dizziness and sedation."


See also

*
Charlotte's Web (cannabis) Charlotte's Web is a brand of high-cannabidiol (CBD), low-tetrahydrocannabinol (THC) products derived from industrial hemp and marketed as dietary supplements and cosmetics under federal law of the United States. It is produced by Charlotte's W ...
*
Chinese herbology Chinese herbology () is the theory of traditional Chinese herbal therapy, which accounts for the majority of treatments in traditional Chinese medicine (TCM). A ''Nature'' editorial described TCM as "fraught with pseudoscience", and said that t ...
*
Tilden's Extract Tilden's Extract was a 19th-century medicinal cannabis extract, first formulated by James Edward Smith of Edinburgh. In the United States, the Tilden Company of New Lebanon, New York, manufactured and sold the extract under its own name, adve ...


References


Further reading

*


External links

, links to websites about medical cannabis
Information on Cannabis and Cannabinoids
from the U.S.
National Cancer Institute The National Cancer Institute (NCI) coordinates the United States National Cancer Program and is part of the National Institutes of Health (NIH), which is one of eleven agencies that are part of the U.S. Department of Health and Human Services. ...

Information on cannabis (marihuana, marijuana) and the cannabinoids
from
Health Canada Health Canada (HC; )Health Canada is the applied title under the Federal Identity Program; the legal title is Department of Health (). is the Structure of the Canadian federal government#Departments, with subsidiary units, department of the Gove ...

The Center for Medicinal Cannabis Research of the University of California

''Medical Marijuana''
– a 2014–2015 three-part
CNN Cable News Network (CNN) is a multinational news organization operating, most notably, a website and a TV channel headquartered in Atlanta. Founded in 1980 by American media proprietor Ted Turner and Reese Schonfeld as a 24-hour cable ne ...
documentary produced by
Sanjay Gupta Sanjay Gupta (born October 23, 1969) is an American neurosurgeon, medical reporter, and writer. He serves as associate chief of the neurosurgery service at Grady Memorial Hospital in Atlanta, Georgia, associate professor of neurosurgery at ...
* {{Navboxes , title=Articles related to medical cannabis , list= {{Ancient anaesthesia-footer {{Cannabinoidergics {{Drug use {{Herbal Sedatives {{Medicinal herbs & spices {{Psychoactive substance use Antiemetics Antioxidants Biologically based therapies Herbalism Medical ethics Medicinal plants Pharmaceuticals policy Pharmacognosy