MSM

Also known as methylsulfonylmethane, msm sulfur.

Last reviewed October 9, 2026 · Jump to references

What is MSM?

In plain words

MSM is a sulfur-containing substance found naturally in small amounts in some foods and in the body. The body absorbs it through the gut and removes much of it through urine. Researchers study it mainly for joint pain and stiffness, especially in knee arthritis. Small studies suggest possible symptom relief, but the evidence is limited and long-term safety is not well established.

Technical definition

Methylsulfonylmethane (MSM; dimethyl sulfone) is a small organosulfur compound with the formula (CH₃)₂SO₂ that occurs naturally in trace amounts in foods and the human body. No specific therapeutic receptor or molecular target is established; laboratory studies suggest effects on inflammatory signaling and oxidative stress, but their clinical relevance remains uncertain. In the United States, MSM is marketed as a dietary supplement and is not FDA-approved to treat disease.

Educational information only. This page does not provide medical advice or determine whether a supplement is appropriate for you. Review supplements with a qualified healthcare professional, especially if you take medication, are pregnant, have surgery scheduled, or have a chronic medical condition.

Evidence by use

Each use is rated on its own. There is no single overall effectiveness score.