Dimethyl sulfone (DMSO₂) is an

organosulfur compound Organosulfur chemistry is the study of the properties and synthesis of organosulfur compounds, which are organic compounds that contain sulfur. They are often associated with foul odors, but many of the sweetest compounds known are organosulfur der ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

. It is also known by several other names including methyl sulfone and (especially in alternative medicine) methylsulfonylmethane (MSM). This colorless solid features the

sulfonyl In organosulfur chemistry, a sulfonyl group is either a functional group found primarily in sulfones, or a substituent obtained from a sulfonic acid by the removal of the hydroxyl group, similarly to acyl groups. Group Sulfonyl groups can be w ...

functional group In organic chemistry, a functional group is any substituent or moiety (chemistry), moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions r ...

and is the simplest of the sulfones. It is relatively inert chemically and is able to resist decomposition at elevated temperatures. It occurs naturally in some primitive plants, is present in small amounts in many foods and beverages, and is marketed (under the MSM name) as a

dietary supplement A dietary supplement is a manufactured product intended to supplement a person's diet by taking a pill (pharmacy), pill, capsule (pharmacy), capsule, tablet (pharmacy), tablet, powder, or liquid. A supplement can provide nutrients eithe ...

. It is sometimes used as a

cutting agent Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for cutting are the knife and saw, or in medicine and science the scalpel and m ...

for illicitly manufactured

methamphetamine Methamphetamine (contracted from ) is a potent central nervous system (CNS) stimulant that is mainly used as a recreational drug use, recreational or Performance-enhancing substance, performance-enhancing drug and less commonly as a secon ...

. It is also commonly found in the atmosphere above marine areas, where it is used as a carbon source by the airborne bacteria '' Afipia''. Oxidation of

dimethyl sulfoxide Dimethyl sulfoxide (DMSO) is an organosulfur compound with the formula . This colorless liquid is the sulfoxide most widely used commercially. It is an important polar aprotic solvent that dissolves both polar and nonpolar compounds and is ...

produces the sulfone, both under laboratory conditions and metabolically.

Use as a solvent

Because of its polarity and thermal stability, molten DMSO₂ has been used industrially as a high-temperature

solvent A solvent (from the Latin language, Latin ''wikt:solvo#Latin, solvō'', "loosen, untie, solve") is a substance that dissolves a solute, resulting in a Solution (chemistry), solution. A solvent is usually a liquid but can also be a solid, a gas ...

. For example, displacement of aryl chlorides by

potassium fluoride Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide salt and occurs naturally as the ...

has been conducted in the liquid. With a p''K''_a of 31, the sulfone can be deprotonated with

sodium amide Sodium amide, commonly called sodamide (systematic name sodium azanide), is the inorganic compound with the formula . It is a salt composed of the sodium cation and the azanide anion. This solid, which is dangerously reactive toward water, is whit ...

. The conjugate base has been used as a

nucleophile In chemistry, a nucleophile is a chemical species that forms bonds by donating an electron pair. All molecules and ions with a free pair of electrons or at least one pi bond can act as nucleophiles. Because nucleophiles donate electrons, they are ...

Medical and dietary use

Methylsulfonylmethane is marketed as a dietary supplement with medical claims ranging from anti-inflammatory effects for pain management, skin condition and aging treatments, and immune system modulation. No medical uses for MSM have been approved and there is limited evidence to support most of the claims. Small studies of MSM have suggested some benefit for treatment of oxidative stress and osteoarthritis, but evidence for other uses is lacking.

Osteoarthritis

Methylsulfonylmethane may or may not be useful for

osteoarthritis Osteoarthritis is a type of degenerative joint disease that results from breakdown of articular cartilage, joint cartilage and underlying bone. A form of arthritis, it is believed to be the fourth leading cause of disability in the world, affect ...

(OA) knee pain relief. Methodological issues with the clinical trials prevent firm conclusions, and the review authors stated: "No definitive conclusion can currently be drawn" and there is "no definitive evidence that MSM is superior to placebo in the treatment of mild to moderate osteoarthritis of the knee."

Oxidative stress and inflammation

Multiple human and animal trials indicate MSM may reduce oxidative stress and inflammation.

Contraindications and safety

In July 2007 a manufacturer of MSM submitted a notification to the U.S. FDA claiming

generally recognized as safe Generally recognized as safe (GRAS) is a United States Food and Drug Administration (FDA) designation that a chemical or substance added to food is considered safe by experts under the conditions of its intended use. An ingredient with a GRAS d ...

(GRAS) status. GRAS status is for safety, and has no evaluation of efficacy. The FDA responded in February 2008 with a letter of non-objection, functionally designating OptiMSM, the branded form of MSM, as GRAS. The designation allows MSM to be added to

processed foods Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing takes many forms, from grinding grain into raw flour, home cooking, and complex industrial methods used in the mak ...

. The of MSM is greater than 17.5 grams per kilogram of body weight. Extensive research in animal models indicates MSM has a very low toxicity when administered both orally and topically. MSM is considered 'Possibly Safe' at therapeutic doses.

Pharmacology

Pharmacology and toxicity

Nuclear magnetic resonance Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a ...

(NMR) studies have demonstrated that oral doses of MSM are absorbed into the blood and cross the blood/brain barrier. An NMR study has also found detectable levels of MSM normally present in the blood and

cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ...

, suggesting that it derives from dietary sources, intestinal bacterial metabolism, and the body's endogenous

methanethiol Methanethiol (also known as methyl mercaptan) is an organosulfur compound with the chemical formula . It is a colorless gas with a distinctive putrid smell. In small amounts, it is pervasive in nature and found in certain foods, such as some n ...

metabolism.

Mechanism of action

The mechanism of action underlying MSM's medical claims is not clear. Some promoters suggest that most people do not consume enough sulfur. There is no

Dietary Reference Intake The Dietary Reference Intake (DRI) is a system of nutrition recommendations from the National Academy of Medicine (NAM) of the National Academies (United States). It was introduced in 1997 in order to broaden the existing guidelines known as Rec ...

(DRI) or Daily Value established for sulfur, but it is present in significant amounts in foods such as

cruciferous vegetables Cruciferous vegetables are vegetables of the family Brassicaceae (also called Cruciferae) with many genera, species, and cultivars being raised for food production such as cauliflower, cabbage, kale, garden cress, bok choy, broccoli, Brusse ...

garlic Garlic (''Allium sativum'') is a species of bulbous flowering plants in the genus '' Allium''. Its close relatives include the onion, shallot, leek, chives, Welsh onion, and Chinese onion. Garlic is native to central and south Asia, str ...

onions An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus ''Allium''. The shallot is a botanical variety of the onion which was classified ...

asafoetida Asafoetida (; also spelled asafetida) is the dried latex (Natural gum, gum oleoresin) exuded from the rhizome or tap root of several species of ''Ferula'', perennial herbs of the carrot family. It is produced in Iran, Afghanistan, Central As ...

legumes Legumes are plants in the pea family Fabaceae (or Leguminosae), or the fruit or seeds of such plants. When used as a dry grain for human consumption, the seeds are also called pulses. Legumes are grown agriculturally, primarily for human consu ...

, nuts,

seeds In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be sown, which may include seed and husk or tuber. Seeds are the ...

plant milk Plant milk is a category of non-dairy beverages made from a water-based plant extract for flavoring and aroma. Nut milk is a subcategory made from nuts, while other plant milks may be created from grains, pseudocereals, legumes, seeds or endosp ...

, animal milk and

eggs An egg is an organic vessel in which an embryo begins to develop. Egg, EGG or eggs may also refer to: Biology * Egg cell, the female reproductive cell (gamete) in oogamous organisms Food * Eggs as food Places * Egg, Austria * Egg, Switzerland ...

(both whites and yolks). The claims for the need for sulfur supplementation originate with Robert Herschler, a

biochemist Biochemists are scientists who are trained in biochemistry. They study chemical processes and chemical transformations in living organisms. Biochemists study DNA, proteins and Cell (biology), cell parts. The word "biochemist" is a portmanteau of ...

who filed a patent for using MSM as a

in 1982. Moreover, in cases involving topical therapeutics, the role of MSM as an active agent, per se, versus its having a role in promoting skin permeation (in manner, akin to its solvent relative DMSO) must be characterized/controlled. The biochemical effects of supplemental methylsulfonylmethane are poorly understood. Some researchers have suggested that MSM has

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. The spectrum of biological effects of dimethyl sulfoxide (DMSO) and MSM differ, but those of DMSO may be mediated, at least in part, by MSM.

Research

Skin, hair, nails

The first scientific investigation of MSM for skin health was published in 2015. The RCT used a 3g per day dose and included only 20 women. Results showed significant improvements in the number and severity of facial wrinkles, firmness, tone and texture. Another study evaluated doses of 1g and 3g and showed improvements in wrinkles, firmness, and hydration at both dose levels in 20 persons. The same author published a study on MSM for hair and nails from the same clinical trial. The results showed improvements in hair shine, volume, and appearance, and nail shine and appearance. An Italian study evaluated the effects of a nutraceutical composed of MSM,

hyaluronic acid Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminog ...

, and L-carnosine. The results from RCT showed broad improvements in facial skin hydration and elasticity, as well as decreased sebaceous secretions.

Oxidative stress and inflammatory response

In one small human trial, MSM has been shown to protect muscles from damage by reducing the amount of oxidative stress damage incurred through exercise. In a second small trial the total antioxidant capacity was significantly increased after taking MSM. Studies in animals indicate a hepatoprotective effect of MSM against several toxins including

acetaminophen Paracetamol, or acetaminophen, is a non-opioid analgesic and antipyretic agent used to treat fever and mild to moderate pain. It is a widely available over-the-counter drug sold under various brand names, including Tylenol and Panadol. Parac ...

paraquat Paraquat ( trivial name; ), or ''N'',''N''′-dimethyl-4,4′-bipyridinium dichloride (systematic name), also known as methyl viologen, is a toxic organic compound with the chemical formula C6H7N)2l2. It is classified as a viologen, a family o ...

, and

carbon tetrachloride Carbon tetrachloride, also known by many other names (such as carbon tet for short and tetrachloromethane, also IUPAC nomenclature of inorganic chemistry, recognised by the IUPAC), is a chemical compound with the chemical formula CCl4. It is a n ...

. Animal models of experimental colitis and pulmonary hypertension indicate a protective effect as well.

Allergies and immunity

Two studies have evaluated the effects of MSM on allergic rhinitis. A 2004 multi-centered, open-label clinical trial found that MSM reduced both upper and lower respiratory symptoms associated with seasonal

allergic rhinitis Allergic rhinitis, of which the seasonal type is called hay fever, is a type of inflammation in the nose that occurs when the immune system overreacts to allergens in the air. It is classified as a type I hypersensitivity reaction. Signs a ...

(SAR), and increased energy levels. It found no significant changes in

IgE Immunoglobulin E (IgE) is a type of antibody (or immunoglobulin (Ig) " isoform") that has been found only in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains (ε chain) and two light chains, with the ε ...

levels, although the duration of the study was not likely long enough to see changes. An RCT evaluated three doses of MSM and found that a 3g daily dose was most effective compared to 1g or 6g per day. Daily use at 3g decreased allergy-associated symptoms, including itchy eyes, itchy nose, watery eyes,

rhinorrhea Rhinorrhea (American English), also spelled rhinorrhoea or rhinorrhœa (British English), or informally runny nose is the free discharge of a thin mucus fluid from the nose; it is an extremely common condition. It is a common symptom of allergie ...

, sneezing, and nasal obstruction. The 3g dose also improved peak nasal inspiratory flow (PNIF) indicating improved breathing. The study also evaluated an acute 12g dose and found significant improvements in all symptoms except itching eyes and sneezing, but not for PNIF. MSM has been shown to improve immune function markers. RCT found that in blood samples taken after bouts of exhaustive exercise, there was a reduced response to an infectious stimulus in the placebo group, but the MSM group maintained a robust response, indicating that MSM protected against stress-induced

immunosuppression Immunosuppression is a reduction of the activation or efficacy of the immune system. Some portions of the immune system itself have immunosuppressive effects on other parts of the immune system, and immunosuppression may occur as an adverse react ...

. The authors postulate that MSM’s anti-inflammatory properties reduce the overstimulation of inflammatory cells during exercise, thus conserving their ability to respond to infections threats. This is supported by ''in vitro'' research showing MSM inhibits over-activation of white blood cells and has an anti-

apoptotic Apoptosis (from ) is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemical events lead to characteristic cell changes ( morphology) and death. These ...

effect.

Notes

{{Authority control Dietary supplements Experimental medical treatments Solvents Sulfones Food additives Methyl compounds