What is it?

MSM is rich in organic sulphur, an important ‘building block’ for healthy bones and joints, and it’s very useful for your immune system. Available evidence from short-term RCTs shows that MSM may have a moderate effect in improving joint pain and swelling as well as general functional wellbeing in people with osteoarthritis. In one trial this effect was greater when MSM was combined with glucosamine.

  • Family: Organic sulphur (nutritional mineral)
  • Scientific name: : Methylsulfonylmethane
  • Other names: OptiMSM®

Methylsulfonylmethane is a sulphur (a chemical) found in fresh raw foods including fruits, vegetables and meat. The compound used to treat diseases, MSM, is a white crystalline substance that contains 34% sulphur. You can buy it from high-street shops.

How does it work?

Laboratory studies have found that MSM has anti-inflammatory and antioxidant effects. Sulphur, which is a major component of MSM, plays an important role in making collagen and glucosamine, both of which are vital for healthy bones and joints, and in the production of immunoglobulins, which help your immune system.

Is it safe?

Evidence suggests that MSM is well tolerated as a short-term treatment, even with high doses. A daily dose of 1,500 mg per day for up to three months was used in one RCT in participants with osteoarthritis, but doses up to 2,600 mg per day have been used in non-RCT studies.

Only mild side-effects have been reported, the most common of which was gastrointestinal discomfort. The long-term side-effects of MSM haven’t yet been studied.

There are no well-known interactions but MSM has been reported to improve the effect of glucosamine in reducing pain and swelling in osteoarthritis.

MSM trials for osteoarthritis

Trial 1

In the first trial, 118 participants with osteoarthritis of the knee were randomly given one of the following treatments once a day for 12 weeks:

  • 1.5 g glucosamine
  • 1.5 g MSM capsules
  • both glucosamine and MSM
  • placebo capsules.

The trials found the following results:

  • Participants given MSM or glucosamine showed a significant improvement in pain and joint swelling compared to participants who were given a placebo.
  • The degree of pain reduction was similar in both groups, but glucosamine seemed to have a better effect in reducing joint swelling.
  • The group who were given both glucosamine and MSM had the most significant reduction in both pain and swelling compared to the other three treatment groups.
  • The combined treatment group had the best functional ability of joints at the end of the trial period.
  • MSM was well tolerated with no significant side-effects reported.

Trial 2

In the second RCT, 50 participants with osteoarthritis-related knee pain were given either 6 g MSM capsules or placebo capsules for 12 weeks.

  • Only 25% of participants taking MSM showed some improvement of pain and physical function compared to those who took the placebo.
  • There was no difference in stiffness.

Trial 3

This trial has only been published as a conference summary so we don’t know about the quality. Sixty participants with knee osteoarthritis were randomised to take either 3.375 g MSM capsules or placebo capsules once a day for 12 weeks.

Participants who were on MSM showed improvement in pain and general functional well-being compared to those who took the placebo.

MSM didn’t have an effect on improving knee function (for example walking, climbing stairs).