MSM (Methylsulfonylmethane)

What is MSM and what does it do in the body?

MSM is a sulfur-containing compound. According to the review by Butawan and colleagues, MSM’s most common purpose of use is an anti-inflammatory effect; the review reports that various outcomes such as inflammation, joint and muscle pain, oxidative stress, and antioxidant capacity improved with MSM, and states that MSM is considered a “generally recognized as safe” (GRAS) substance in the US. According to the review’s conflict-of-interest statement, one of the authors works at an MSM manufacturing company and another received research funding and consulting fees from supplement companies, including companies that sell MSM; for this reason, the review’s favorable framing is not read as independent evidence. ^[8]

The biological role of a compound or supplement in the body and the benefit of an amount taken by mouth are separate questions. On the dose–time relationship of MSM, Butawan’s review states that additional studies to determine the optimal dose and treatment duration are ongoing; that is, there is no established value for this. ^[8]

In what forms is MSM found?

In Türkiye, the Ministry of Agriculture and Forestry’s Restricted Substances List names only the “chemical synthesis” source for MSM. ^[13] In supplements, MSM appears alone as well as in formulas together with glucosamine and chondroitin; the study examining the triple mixture is addressed below. ^[6] In mixtures, which component the results depend on cannot be distinguished in these designs; for this reason, the benefit in mixture studies is not read as MSM’s own effect.

Does MSM help pain in knee osteoarthritis?

Short answer: the evidence is small, mixed, and of uncertain clinical importance.

Systematic reviews (Brien 2008, 2011)

The 2008 systematic review by Brien and colleagues examined DMSO and MSM studies together: 6 studies in patients with knee osteoarthritis; 2 studies for MSM (168 patients in total). Two of the DMSO studies and both MSM studies reported significant improvement in pain compared with comparator treatments; however, methodological problems and concerns about the optimum dose and treatment duration were emphasized. The authors concluded that the more rigorous MSM studies provided favorable but inconclusive evidence of superiority over placebo and stated that the optimum dose and long-term safety need to be determined. ^[1]

The same group’s 2011 meta-analysis analyzed 3 randomized studies out of 7 potential studies (2 DMSO, 1 MSM; 326 patients in total); all three were judged to be of high methodological quality, and there was significant heterogeneity among them. Two studies showed a statistically significant (but not clinically important) reduction in pain, and one showed no difference. In the pooled analysis, the pain VAS difference was 6.34 mm (95% CI −0.49 to 13.17); the overall effect size (1.82) was neither statistically nor clinically significant. The authors stated that the available evidence suggests DMSO and MSM are not effective in clinically reducing pain, but that a firm conclusion cannot be drawn because of mixed findings and inadequate dosing durations. The majority of the analysis consists of DMSO studies, not MSM. ^[2]

Individual studies

• Debbi 2011 (Israel): ages 45–90, 49 patients with knee osteoarthritis; 1.125 g of MSM three times daily or placebo, 12 weeks. The difference in WOMAC physical function was 14.6 mm (95% CI 4.3–25.0; p=0.04), in WOMAC total 15.0 mm (5.1–24.9; p=0.03); there was no significant difference in WOMAC pain (12.4 mm; 0.0–24.8; p=0.08) and stiffness; VAS pain p=0.05. The authors stated that the improvements were small and the clinical importance remained uncertain. ^[3]
• Tennent 2017 (US Army): 180 military recruits aged 18–40; 3 g/day of MSM or placebo for 8 weeks. No significant improvement was seen on the 5 subscales of KOOS and the 6 subscales of POMS at days 30 and 60; the authors stated that 3 g/day can be used safely. This study examined the question of preventing knee pain, not treating osteoarthritis. ^[4]
• Toguchi 2023 (Japan): 88 participants with mild knee pain; 10 tablets/day (each 200 mg of MSM) or lactose, 12 weeks. The JKOM total score differed between groups at week 12 (p=0.046). One of the authors works in the R&D department of a food company. ^[5]
• Lubis 2017 (Indonesia): 147 patients with Kellgren-Lawrence grade I–II knee osteoarthritis; glucosamine–chondroitin, glucosamine–chondroitin–MSM, or placebo, 3 months. At week 12, there was a difference between groups in WOMAC (p=0.03) and VAS (p=0.004); the authors stated that glucosamine–chondroitin alone did not produce clinical improvement. Because there was no MSM-alone arm, MSM’s contribution cannot be separated. ^[6]

MSM in the supplement meta-analysis

In the 2018 meta-analysis by Liu and colleagues (69 studies, 20 supplements; placebo-controlled RCTs), collagen hydrolysate, Curcuma longa extract, curcumin, and others reported large effects, while six supplements, including MSM, undenatured type II collagen, avocado–soybean unsaponifiables, diacerein, glucosamine, and chondroitin, showed statistically significant but clinically uncertain improvement in pain. No supplement was found to have a clinically important effect on pain in the long term; evidence quality ranged from very low to high. ^[7]

Is MSM effective for post-exercise muscle pain and seasonal allergy?

There are only very small studies in these two areas.

• Half-marathon (Withee 2017): 22 healthy adults (33.7±6.9 years; 17 women) received 3 g/day of MSM or placebo for 21 days before and 2 days after the race. The primary outcome was the oxidative stress marker 8-OHdG; the time-treatment interaction was not significant on any outcome measure. In the MSM group, the reduction in muscle and joint pain exceeded the clinically significant threshold (>10 mm) but was not statistically significant. According to the article’s conflict-of-interest statement, the first author worked at the product’s manufacturer during the study period (it is stated that he did not receive payment for the study). ^[10]
• 14 km run (Barmaki 2012, Iran): 18 healthy young men received 50 mg/kg of MSM or placebo for 10 days. At 24 hours after exercise, creatine kinase and bilirubin were higher in the placebo group than in the MSM group (P=0.041 and P=0.002); total antioxidant capacity increased in the MSM group. ^[11] Both studies are small and their results are discordant with each other.
• Seasonal allergic rhinitis (Barrager 2002): 55 people were enrolled and 50 completed; in an open-label study with no placebo arm, 2,600 mg/day of MSM was used for 30 days. Upper and total respiratory symptoms decreased from baseline at day 7 and lower respiratory symptoms at week 3; there was no significant change in plasma IgE and histamine levels. The authors stated that a larger, double-blind, placebo-controlled study would be valuable. Because there was no control group, the symptom change cannot be attributed to MSM. ^[12]

How is the quality of MSM studies assessed?

The common features of MSM studies are small samples and short duration: 49 (Debbi), 147 (Lubis), and 88 (Toguchi) participants in the osteoarthritis studies; 18 and 22 participants in the exercise studies; and 50 completers in the allergic rhinitis study. ^{[3] [6] [5] [11] [10] [12]} The Brien 2011 meta-analysis contains only one study for MSM and therefore does not offer an MSM-specific pooled estimate. ^[2] In the abstracts, the product used in the Tennent, Withee, and Crawford studies is described as a commercial MSM product belonging to the same manufacturer; one of the authors of the Butawan review is also an employee of the same company. ^{[4] [10] [9] [8]} In the Toguchi study, one of the authors is in the R&D department of a different food company. ^[5] These links do not show that the results are wrong; they do show that a significant share of the MSM studies addressed here are manufacturer-linked and that none of them is a large, independent, placebo-controlled study. The Liu 2018 meta-analysis also reports that MSM falls, together with commonly used supplements, in the category of benefit of uncertain clinical importance. ^[7]

Is MSM safe?

In the safety substudy of the 16-week RCT by Crawford and colleagues at 6 g/day MSM (patients with osteoarthritis and low back pain), no significant difference from placebo was found in white blood cells, platelets, hemoglobin, total bilirubin, ALT, AST, creatinine, weight, and blood pressure. ^[9] Butawan and colleagues relay that MSM is well tolerated by most people at doses up to 4 g/day and that few mild side effects have been reported; one of the review’s authors is a manufacturer employee. ^[8] In Tennent’s study, 3 g/day for 8 weeks was found safe. ^[4] The Brien 2008 review states that long-term safety needs to be studied separately. ^[1] These studies are short and small; the reported results do not cover pregnancy, breastfeeding, and drug interactions.

How is MSM regulated in Türkiye?

In Türkiye, food supplements are regulated by the Ministry of Agriculture and Forestry, and Ministry approval is mandatory for every food supplement to be placed on the market. ^[14] In the Restricted Substances List (last updated September 21, 2026), the methylsulfonylmethane (MSM) row reads as follows: source “chemical synthesis”; 6,000 mg/day in the 11 years and older daily intake dose column; the ages 4–10 column is empty; first publication date January 22, 2016. The label is required to carry the warnings “18 yaş altı bireylerde kullanılmaz.” (not for use by individuals under 18) and “Bu takviye edici gıdanın 3 aydan fazla kullanılması durumunda doktora danışılmalıdır.” (a doctor should be consulted if this food supplement is used for more than 3 months) (March 9, 2017; updated August 3, 2017). ^[13] The upper limit in the list is in the same unit as the amounts used in the studies (mg/day) but is not evidence of benefit.

Evidence table: claim, population, and limits