Meta-analysis of the related nutritional supplements dimethyl sulfoxide and methylsulfonylmethane in the treatment of osteoarthritis of the knee

Brien S, Prescott P, Lewith G · Evidence-Based Complementary and Alternative Medicine

The pooled result was NOT significant: a 6.34 mm reduction on the visual analogue pain scale (SE 3.49, 95% CI -0.49 to 13.17), with an overall effect size of 1.82 that was neither statistically nor clinically significant. The authors' conclusion is blunt — 'Current evidence suggests DMSO and MSM are not clinically effective in the reduction of pain in the treatment of OA.'

Population

Three randomized controlled trials in knee osteoarthritis — two of DMSO, one of MSM

Intervention

Dimethyl sulfoxide or methylsulfonylmethane

Comparator

Placebo or control

Limitations

Only three trials met inclusion and only ONE of them tested MSM, so this is weak evidence against MSM specifically rather than a decisive refutation. Significant heterogeneity. The authors also note inadequate dosing periods, and say no definitive conclusions can be drawn. Independent (University of Southampton).