MSM (Methylsulfonylmethane)

Methylsulfonylmethane · Dimethyl Sulfone · DMSO2 · Methyl Sulfone

Snapshot

Indications	Contraindications
Knee osteoarthritis pain^{1, 2} Osteoarthritis physical function³ Mild knee pain⁴ Muscle and joint pain⁵ Post-exercise oxidative stress⁶ Skin ageing signs⁷	Pregnancy or breastfeeding⁸ Worsening symptoms during use⁸

Methylsulfonylmethane (MSM) is a sulfur-containing compound found in small amounts in food and sold as an oral supplement.⁵ Its use rests on anti-inflammatory and antioxidant actions, which drive supplementation for joint and muscle pain and for exercise recovery. The typical patient is a middle-aged or older adult with knee osteoarthritis pain¹.

A network meta-analysis of dietary supplements for osteoarthritis pain rated its evidence low quality, and its top pain rankings went to other supplements, such as passion fruit peel extract and collagen⁹. Two placebo-controlled trials of MSM-containing combinations found no pain benefit over placebo in knee or hand osteoarthritis^{10, 11}. A 2022 study of oral supplementation, with a placebo-controlled pilot and a dose comparison, reported fewer facial wrinkles and better skin firmness and hydration. MSM is sold mostly as capsules and tablets; see Form comparison.

Health Canada labels on licensed single-ingredient products ask users to consult a health care practitioner before use in pregnancy or breastfeeding, and if symptoms worsen⁸. Health Canada also lists mild gastrointestinal bloating, constipation, or indigestion as known adverse reactions⁸.

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

41 sources, 32 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources