11-Nor-9-carboxy-Δ⁹-tetrahydrocannabinol (11-COOH-THC or THC-COOH), often referred to as 11-nor-9-carboxy-THC or THC-11-oic acid, is the main secondary

metabolite In biochemistry, a metabolite is an intermediate or end product of metabolism. The term is usually used for small molecules. Metabolites have various functions, including fuel, structure, signaling, stimulatory and inhibitory effects on enzymes, c ...

of tetrahydrocannabinol (THC) which is formed in the body after

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 ...

is consumed.

Metabolism and detection

11-COOH-THC is formed in the body by

oxidation Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is ...

of the active metabolite 11-hydroxy-THC (11-OH-THC) by liver enzymes. It is then metabolized further by conjugation with glucuronide, forming a water-soluble congener which can be more easily excreted by the body. 11-COOH-THC has a long half-life in the body of up to several days (or even weeks in very heavy users), making it the main metabolite tested for blood or urine testing for cannabis use. More selective tests are able to distinguish between 11-OH-THC and 11-COOH-THC, which can help determine how recently cannabis was consumed; if only 11-COOH-THC is present then cannabis was used some time ago and any impairment in cognitive ability or motor function will have dissipated, whereas if both 11-OH-THC and 11-COOH-THC are present then cannabis was consumed more recently and motor impairment may still be present. Recent studies highlight that individual factors such as metabolism, body fat percentage, and frequency of use significantly impact the detection window of 11-COOH-THC in drug testing. Some jurisdictions where cannabis use is decriminalized or permitted under some circumstances use such tests when determining whether drivers were legally intoxicated and therefore unfit to drive, with the comparative levels of THC, 11-OH-THC and 11-COOH-THC being used to derive a "blood cannabis level" analogous to the blood alcohol level used in prosecuting impaired drivers. On the other hand, in jurisdictions where cannabis is completely illegal, any detectable levels of 11-COOH-THC may be deemed to constitute driving while intoxicated, even though this approach has been criticized as tantamount to prohibition of "driving whilst being a recent user of cannabis" regardless of the presence or absence of any actual impairment that might impact driving performance.

Effects

While 11-COOH-THC does not have any psychoactive effects in its own right, it may still have a role in the

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

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 ...

effects of cannabis, and has also been shown to moderate the effects of THC itself which may help explain the difference in subjective effects seen between occasional and regular users of cannabis.

Legal status

The legal status of 11-nor-9-carboxy-THC varies among jurisdictions.

Australia

11-COOH-THC is a Schedule 8 prohibited substance in

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

under the Poisons Standard (July 2016).Poisons Standard July 201
Comlaw.gov.au
/ref> A schedule 8 substance is a controlled Drug – Substances which should be available for use but require restriction of manufacture, supply, distribution, possession and use to reduce abuse, misuse and physical or psychological dependence.

United States

Because 11-COOH-THC is substantially similar to the Schedule I controlled substance THC, possession or sale of 11-COOH-THC could be subject to prosecution under the Federal Analog Act.

References