Methylsulfonylmethane · supplement
Evidence tier: weak
A natural sulfur source for joints, skin, and connective tissue support.
MSM is an organic sulfur compound (dimethyl sulfone) that is absorbed well and enters the body's sulfur pool, where sulfur is used to build connective tissue proteins and to make glutathione, the body's main internal antioxidant. Animal and laboratory work shows it damps inflammatory signalling and oxidative stress. This is a coherent story, and it is the reason the compound keeps getting tested. It is not the same thing as evidence that it relieves joint pain in people, which is what the trials failed to show.
MSM is very safe and very thinly evidenced, and the joint claim it is sold on has never actually cleared the bar. The pooled analysis that matters is the systematic review and meta analysis of DMSO and MSM in knee osteoarthritis: of seven candidate trials only three were eligible, totalling 326 patients, and only ONE of those three was an MSM trial. The trials were methodologically decent and the result was still negative. Two studies showed a statistically significant but not clinically relevant reduction in pain, one showed no group difference, and the pooled reduction on the pain visual analogue scale was 6.34 mm, which was neither statistically nor clinically significant. The authors concluded that current evidence does not support the use of DMSO or MSM for reducing pain in osteoarthritis (Brien and colleagues, Evidence Based Complementary and Alternative Medicine, 2011). Nothing since has overturned that. What has accumulated is a scatter of small positive trials: a 2023 randomised placebo controlled trial reported improved knee quality of life in people with mild knee pain, and later reviews across rheumatic disease still describe the data as sparse, resting on a couple of hundred MSM treated patients in total. Exercise recovery is weaker again: the studies are pilots, one of the most cited involved ten trained runners, and they measure biochemical markers of muscle damage and oxidative stress rather than whether anyone performed or recovered better. Skin elasticity is not an MSM result at all: the trial usually cited gave 1.5 g of MSM TOGETHER with 5 to 10 g of hydrolysed collagen, and a combination product cannot be credited to one of its ingredients. Nothing here is fraudulent, but the honest word for the whole file is small, and small studies of a very safe compound are exactly where wishful reading happens.
1.5 to 6 g daily, in two or three divided doses, is the range used in the osteoarthritis trials, for periods of up to 12 weeks. MSM has GRAS status in the United States and is generally rated safe at up to about 4 g daily; adverse events in trials occurred no more often than with placebo.
1500 to 6000 mg daily in divided doses, with food.
Very safe. Caution with anticoagulants (mild antiplatelet at high doses).
Pregnancy: caution
Breastfeeding: caution
Active compounds: methylsulfonylmethane (dimethyl sulfone), organic sulfur
Remedies using MSM · Browse by body system · Check it against what you take
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.