What Is MSM and Does It Help Joints? Doses, Trials and Side Effects

MSM, short for methylsulfonylmethane, is a sulphur-containing compound found in tiny amounts in milk, fruit, vegetables, coffee and tea, and made in bulk for supplements. It is taken mainly for joint pain and stiffness. Six small knee trials of 49 to 147 people tested it at 0.5 to 6 g a day for 12 weeks: five found at least one pain or function score improved against placebo, and a 2026 trial of a five-ingredient combination containing 1.5 g of MSM found no difference from placebo.^1-7 The trials used grams, so check the grams of MSM per serving on a label. MSM has no authorised health claim in Great Britain, so this page reports what the trials found rather than promising a result.

Sources checked on 30 October 2026.

What is MSM?

MSM is a small molecule of carbon, hydrogen, oxygen and sulphur: two methyl groups on a sulphur atom carrying two oxygens. It is the oxidised form of dimethyl sulfoxide (DMSO), a solvent once studied for joint pain. It turns up at very low concentrations in cow's milk, fruit and vegetables, grains, coffee, tea and beer, at hundredths of a part per million, so no diet supplies the grams the trials used.¹ Supplement MSM is made by oxidising DMSO and purifying the result.¹

What is MSM taken for?

Joint pain and stiffness, above all. The idea has always been that supplying sulphur, a component of connective tissue proteins, in an available form would be useful to joints; that remains a hypothesis rather than something shown in people. The trials that exist measured knee osteoarthritis symptoms over 12 weeks; smaller studies looked at muscle soreness after exercise, and newer ones at skin.¹ Whatever your reason for considering it, the UK first line for painful joints is the same: the NHS puts exercise, weight management and suitable footwear ahead of anything from a tub, and how can I naturally lubricate my joints sets out what that means.¹¹

What did the trials of MSM find?

Six randomised, placebo-controlled trials have tested MSM for knee pain, every one lasting 12 weeks.

Modest positive results in small trials, some with industry involvement, and no large independent trial of MSM alone. The 2008 Southampton systematic review called the evidence "positive but not definitive".⁸ The 2018 meta-analysis of 69 supplement trials placed MSM among the supplements with a statistically significant effect on osteoarthritis pain whose clinical importance was unclear, in the same band as glucosamine and chondroitin.⁹ What is the best joint supplement sets every ingredient's best trial side by side.

Does MSM work better with glucosamine or chondroitin?

Two trials asked directly and both favoured the combination. In the 2004 Indian trial, glucosamine 500 mg plus MSM 500 mg three times a day lowered the pain index from 1.7 to 0.36, against 1.74 to 0.65 for glucosamine alone and 1.53 to 0.74 for MSM alone.⁴ In the 2017 Indonesian trial, adding 500 mg of MSM to glucosamine and chondroitin produced improvements the pair alone did not.⁶ Neither has been repeated, so "better together" rests on two small studies. UK guidance does not recommend glucosamine on the NHS; glucosamine vs chondroitin explains what each is and what its trials found.

How much MSM did the trials use, and how much is in a supplement?

Between 0.5 g and 6 g a day, given once to three times a day, as the table shows.^2-6 The 2017 safety review found MSM well tolerated by most people at up to 4 g a day.¹

If you want the amount the trials used, read the label for grams of MSM per serving.

What are the side effects of MSM, and who should ask a GP?

At the doses studied, side effects were few and mild, and the 6 g trial reported no major adverse events.^{1, 2} Toxicity studies in rats, mice and dogs found MSM well tolerated, but people with kidney or liver disease should ask a GP first.¹

Three groups should ask before starting. Anyone pregnant or breastfeeding, because there are no human data. Anyone on warfarin or another anticoagulant: no interaction with MSM has been established, unlike the glucosamine case reports in why is glucosamine bad for you, but an anticoagulant clinic will want to know about any new supplement. And anyone whose joint is hot, swollen, red or recently injured, where the question is a diagnosis, not a supplement.

Is MSM worth taking?

Judge it on the numbers. Five of six knee trials found small improvements in pain or function over 12 weeks at 0.5 to 6 g a day; their authors asked for larger studies; the one recent university-led trial, of a combination, found nothing beyond placebo; and MSM has no authorised health claim in Great Britain.^2-7 Individual response varies more than the averages suggest, so the fair test is the one the trials ran: a dose in the studied range, taken daily for 12 weeks, with your worst joint's pain and morning stiffness scored before you start and at the end. If the scores have moved, you have your answer; if not, stop. Exercise and weight management remain the UK first line, and the Wellgard joint health guide puts MSM alongside every other joint ingredient's evidence.¹¹

What we don't know

• Whether MSM alone helps in a large trial: the trials so far had 49 to 147 people, and the 2008 review called the evidence positive but not definitive.^{2-6, 8}
• Long-term safety: no trial has run longer than 16 weeks.¹⁰

Frequently asked questions

What does MSM do for the body?

It is a source of sulphur, and in small trials it reduced measures of knee pain and physical function at 0.5 to 6 g a day over 12 weeks.^2-6 No effect has been accepted as an authorised claim in Great Britain.

How long does MSM take to work?

Every positive trial measured at 12 weeks, and the 2004 trial, which also scored at 2, 4 and 8 weeks, found the combination acted sooner than glucosamine alone.⁴ Twelve weeks is the fair trial length.

Can you take MSM every day?

The trials gave it daily for 12 weeks at up to 6 g a day without major adverse events, and the safety review found it well tolerated at up to 4 g a day.^{1, 2} No trial has run longer than 16 weeks.

Does MSM help hair, skin and nails?

The evidence is thin. One study by authors from an MSM supplier found that 1 g or 3 g a day for 16 weeks improved graded facial wrinkles and skin firmness in 63 people, after a 20-person pilot against placebo.¹⁰ No trial has measured hair growth or nail strength in people. MSM carries no authorised hair, skin or nail wording.

Is MSM the same as sulphur?

No. Sulphur is an element; MSM is a compound that contains it, about a third by weight, and the body can use its sulphur to make methionine and cysteine.¹

Sources

1. Butawan M, Benjamin RL, Bloomer RJ. Methylsulfonylmethane: applications and safety. Nutrients, 2017. Narrative review; one author works for an MSM supplier and another reports supplement-industry funding. PubMed 28300758.
2. Kim LS, et al. Methylsulfonylmethane in knee osteoarthritis pain: a pilot trial. Osteoarthritis and Cartilage, 2006. Randomised placebo-controlled pilot trial, 50 people, 12 weeks; funding not stated on PubMed. PubMed 16309928.
3. Debbi EM, et al. Methylsulfonylmethane for knee osteoarthritis: a randomized controlled study. BMC Complementary and Alternative Medicine, 2011. Randomised placebo-controlled trial, 49 people, 12 weeks; funding not stated on PubMed. PubMed 21708034.
4. Usha PR, Naidu MU. Oral glucosamine, methylsulfonylmethane and their combination in osteoarthritis. Clinical Drug Investigation, 2004. Randomised placebo-controlled trial, 118 people, 12 weeks; funding not stated on PubMed. PubMed 17516722.
5. Toguchi A, et al. Methylsulfonylmethane and mild knee pain: a randomized placebo-controlled trial. Nutrients, 2023. Randomised placebo-controlled trial, 88 people, 12 weeks; three of four authors from a supplement company's research department; funding not stated. PubMed 37447322.
6. Lubis AMT, et al. Glucosamine-chondroitin with and without methylsulfonylmethane in knee osteoarthritis. Acta Medica Indonesiana, 2017. Randomised placebo-controlled trial, 147 people, 12 weeks; funding not stated on PubMed. PubMed 28790224.
7. Yuan S, et al. An oral complementary medicine combination for knee osteoarthritis (ATLAS). Osteoarthritis and Cartilage, 2026. Randomised placebo-controlled trial, 84 people, 12 weeks; university-led; funding not stated on PubMed. PubMed 42331134.
8. Brien S, et al. Systematic review of DMSO and MSM in osteoarthritis. Osteoarthritis and Cartilage, 2008. Systematic review, 6 trials; funding not stated on PubMed. PubMed 18417375.
9. Liu X, et al. Dietary supplements for osteoarthritis: a systematic review and meta-analysis. British Journal of Sports Medicine, 2018. Systematic review and meta-analysis, 69 trials; no competing interests declared. PubMed 29018060.
10. Muizzuddin N, Benjamin R. Oral methylsulfonylmethane and signs of skin ageing. International Journal for Vitamin and Nutrition Research, 2022. Placebo-controlled pilot in 20 people and a 63-person dose comparison, 16 weeks; authors from an MSM supplier. PubMed 32083522.
11. NHS. Osteoarthritis: treatment and support. Page last reviewed 20 March 2023 (review overdue). nhs.uk/conditions/osteoarthritis/treatment.

Spotted something out of date? Email support@wellgard.co.uk with the page address and the sentence.

This article is general information, not medical advice. Joint pain with swelling, heat or redness, or pain after an injury, needs a GP, not a supplement; if you are pregnant or breastfeeding, take an anticoagulant, or have kidney or liver disease, ask your pharmacist or GP before starting MSM.