MSM (methylsulfonylmethane)
Summary
MSM is a sulfur compound related to DMSO. Small placebo-controlled trials in knee osteoarthritis and mild knee pain reported modest improvements in pain and function scores (grade C), but a systematic review called the evidence positive but not definitive. Trial doses ran 2 to 6 g a day, and short-term tolerance was good.
Key facts
- An organic sulfur compound (dimethyl sulfone), chemically related to DMSO, found in small amounts in many foods[2][5]
- Knee osteoarthritis pain and function (C); mild knee pain quality-of-life scores (C); post-race muscle soreness (no clear effect, D)[1][2][3]
- Two MSM trials with 168 patients both reported less pain, but methodology was weak; evidence positive but not definitive[5]
- Generally Recognized As Safe (GRAS) and well tolerated by most people at up to 4 g a day in the review literature, with few, mild side effects[6]
- 4 graded human outcomes on this page
- October 11, 2026
How it works
ProposedHuman and animal studies report effects of MSM on inflammation and oxidative-stress markers; how this relates to joint symptoms is not established.[6]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Bones & joints | Grade C | Improved | RCT · n = 88 · 2023 | 2 rows |
| Performance | Grade D | No effect | RCT · n = 22 · 2017 | 1 row |
| Heart | Grade D | Mixed | RCT · n = 22 · 2021 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Knee quality-of-life score in mild knee pain | Improved | Grade C | RCT · n = 88 · 2023 Healthy Japanese adults with mild knee pain Form: MSM tablets · Dose: 2 g/day (10 × 200 mg tablets) · Duration: 12 weeks Total Japanese Knee Osteoarthritis Measure score at 12 weeks was better with MSM than placebo (p = 0.046). | 37447322 (opens PubMed)Source [2] |
| Knee osteoarthritis pain and physical function | Improved | Grade C | Pilot RCT · n = 50 · 2006 Men and women aged 40–76 with knee osteoarthritis pain Form: MSM · Dose: 3 g twice a day (6 g/day) · Duration: 12 weeks WOMAC pain and physical-function scores fell more than with placebo, and SF-36 daily-activity scores improved; no major adverse events. | 16309928 (opens PubMed)Source [1] |
| Oxidative stress, muscle damage and soreness after a half-marathon | No effect | Grade D | RCT · n = 22 · 2017 Healthy recreational runners Form: OptiMSM · Dose: 3 g/day · Duration: 21 days before and 2 days after the race No reduction in oxidative-stress or muscle-damage markers; muscle and joint pain was lower by a margin the authors called clinically but not statistically significant. | 28736511 (opens PubMed)Source [3] |
| HDL cholesterol in overweight and obese adults | Mixed | Grade D | RCT · n = 22 · 2021 Healthy overweight or obese adults Form: MSM · Dose: 3 g/day · Duration: 16 weeks HDL cholesterol rose at 8 and 16 weeks compared with baseline in the MSM group; inflammation and oxidative-status markers were also measured. | 34684621 (opens PubMed)Source [4] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| MSM powder or capsules | Varies[6][1] | No head-to-head human absorption data between brands or forms in our sources.[6][1] | Well tolerated at up to about 4 g a day in the review literature; mild stomach upset is the usual complaint.[6][1] | Knee osteoarthritis and joint pain (2–6 g/day), exercise recovery (3 g/day) |
Studied doses
Doses studied in human trials ranged from 2 to 6 g of MSM a day for 3 to 16 weeks, usually split into two doses.[1][2][3][4]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
None found in our sources.
Who should be careful
- Pregnancy and breastfeeding
- No safety data in pregnancy or breastfeeding were found in the trials or review we cite.[6]
- Long-term use
- Trials lasted 16 weeks or less; the systematic review calls for longer-term safety data.[5]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Where to buy MSM (methylsulfonylmethane)
Products from brands we partner with that contain MSM (methylsulfonylmethane). Listing a product is not a claim that it works; check the amount per serving against the doses studied above, and the label for other ingredients.
- SupersmartPaid linkOptiMSM Supplement (powder)2 scoops: 8 g OptiMSM methylsulfonylmethane (4 g per scoop); 25 servings per 200 g tub; the full label serving is above the 2–6 g/day used in the trials aboveShop at Supersmart (opens in new tab)Price and label checked 2026-10-11 on the brand’s site.
Partner links may earn us a commission. Learn more
Get 15% off with SMART026 (opens in new tab)15% off with code SMART026
Partner links may earn us a commission. Learn more
- Supersmart’s own terms and exclusions apply at checkout.
- 20% applies when 3 or more products ship on auto-delivery to the same address.
- The code discount and Subscribe & Save are separate offers; we don’t claim they combine.
- Offer terms from Supersmart’s site and its affiliate program, checked Oct 8, 2026. Offers can change; the brand's checkout is final.
Frequently asked questions
Does MSM help knee pain?
Two small 12-week trials reported better knee pain or quality-of-life scores than placebo, but a systematic review judged the evidence positive but not definitive.[1][2][5]
Is MSM safe?
It has GRAS status and was well tolerated at up to about 4 g a day in the studies reviewed; long-term data are limited.[6][5]
Is MSM the same as DMSO?
No. MSM (dimethyl sulfone) is a chemically related compound; the two were reviewed together for osteoarthritis.[5][6]
Does MSM help after running?
In 22 half-marathon runners, 3 g a day did not lower muscle-damage markers; pain differences were not statistically significant.[3]
Sources
- [1]Efficacy of methylsulfonylmethane (MSM) in osteoarthritis pain of the knee: a pilot clinical trial.. Osteoarthritis Cartilage, 2006. pilot-RCT
- [2]Methylsulfonylmethane Improves Knee Quality of Life in Participants with Mild Knee Pain: A Randomized, Double-Blind, Placebo-Controlled Trial.. Nutrients, 2023. RCT
- [3]Effects of Methylsulfonylmethane (MSM) on exercise-induced oxidative stress, muscle damage, and pain following a half-marathon: a double-blind, randomized, placebo-controlled trial.. J Int Soc Sports Nutr, 2017. RCT
- [4]The Effect of Daily Methylsulfonylmethane (MSM) Consumption on High-Density Lipoprotein Cholesterol in Healthy Overweight and Obese Adults: A Randomized Controlled Trial.. Nutrients, 2021. RCT
- [5]Systematic review of the nutritional supplements dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) in the treatment of osteoarthritis.. Osteoarthritis Cartilage, 2008. systematic-review
- [6]Methylsulfonylmethane: Applications and Safety of a Novel Dietary Supplement.. Nutrients, 2017. review
What changed
- Independent review: flagged that the listed product’s full serving (8 g) is above the doses studied.
- First draft. Every PMID checked against NCBI E-utilities (title, year and journal taken from the PubMed record; retraction and expression-of-concern flags checked: none) and abstracts read for each cited row. Product details in Where to buy read from the brand page on the date shown.