MSM for Arthritis: Dosage, Benefits and Side Effects

Supplies bioavailable sulfur used in the synthesis of glycosaminoglycans and collagen, and in glutathione production. Anti-inflammatory activity has been reported through inhibition of NF-kB signalling and reduced pro-inflammatory cytokine expression. The connection between supplying sulfur and improving joint symptoms remains an inference rather than a demonstrated chain.

• Osteoarthritis symptoms: a 12-week randomised trial at 1,125 mg three times daily found significant differences in WOMAC physical function and total score.
• Combination with glucosamine and chondroitin: some trials find the addition helps in mild disease, others do not separate it from the base combination.
• Exercise-induced muscle soreness: preliminary, small trials.
• Negative result worth knowing: 3 g/day for 8 weeks in 180 subjects produced no significant improvement on the measures used.

Kim 2006 pilot trial of MSM in knee osteoarthritis pain, Debbi 2011 randomised controlled study finding WOMAC improvements at 1,125 mg three times daily, and a 2017 randomised controlled trial in military trainees at 3 g/day that found no significant improvement. Reading them together, the honest position is a small effect that does not reproduce reliably.

3-6 g/day, usually divided. The positive WOMAC trial used 1,125 mg three times daily for 12 weeks; a pilot trial used 3 g twice daily. Trials running less than 12 weeks are more likely to be negative, which may reflect the timeframe rather than the compound.

Mild and mostly GI: bloating, nausea, diarrhoea. Headache and insomnia are reported. Well tolerated in trials at up to 6 g/day.

No well-documented drug interactions. Because it is often sold combined with glucosamine, anyone on warfarin should be aware that glucosamine has been reported to potentiate it, even though MSM itself has not.