Methylsulfonylmethane offers relief in knee OA

Janis Kelly

August 29, 2005

August 29, 2005

Phoenix, AZ - The popular dietary supplement methylsulfonylmethane (MSM) modestly improves pain and function in patients' knee osteoarthritis (OA) and might be considered for short-term pain relief when other treatments are ineffective, according to Dr Linda Kim (Southwest College of Naturopathic Medicine, Tempe, AZ). Kim and colleagues reported a randomized, placebo-controlled trial of MSM at the American Association Naturopathic Physicians (AANP) 20th annual meeting [ 1 ].

If the COX-2 inhibitors are contraindicated, a patient might give MSM a try.

"If the COX-2 inhibitors are contraindicated, a patient might give MSM a try," Kim tells rheumawire. "This provides only symptomatic relief, but MSM was associated with no problems or adverse effects in our study."

Modest but significant benefits seen with MSM

The study, which was presented at the AANP meeting by coauthor Dr Leslie Axelrod (Southwest College of Naturopathic Medicine, Tempe, AZ), randomized 50 patients to 12 weeks of MSM (n=25) or placebo (n=25). Eligible patients had documented knee OA (Kellgren-Lawrence grade 2 or 3) and significant pain (at least 40 mm on a 0-100 mm visual analog scale [VAS]). Other types of arthritis or chronic pain were excluded.

Patients had a washout of seven days for NSAIDs or other OA treatments and then were randomized to 3 g bid of MSM (OptiMSM, Cardinal Nutrition) or to an identical-appearing placebo capsule. MSM patients took 1 g bid for the first two days, then increased to 3 g bid by the end of the first week of treatment.

The primary study end points were the WOMAC Index, the patient and physician global assessments of overall arthritis disease status and response to therapy, and laboratory measures including serum homocysteine, C-reactive protein, erythrocyte sedimentation rate, urine malondialdehyde (MDA), complete blood count/chemistry panel, fasting lipids, urinalysis, and stool occult blood test, all measured at baseline and again at 12 weeks.

Axelrod reported data for 21 MSM patients and 19 placebo patients who completed the trial. At week 12, WOMAC pain scores dropped by 14.6 mm in MSM patients vs 7.3 mm with placebo (12% difference, p=0.041). Function scores improved by 15.7 mm in MSM patients vs 8.8 mm in placebo patients (13.7% difference, p=0.045).

MSM improves pain, function in knee OA

Outcome measure
WOMAC pain baseline
Pain change at 12 weeks
WOMAC function baseline
Function change at 12 weeks

To download table as a slide, click here

Homocysteine at 12 weeks decreased from 8.0 to 7.2 ¿mol/L in the MSM group (p=0.004 vs placebo). Urine MDA, a measure of lipid peroxidation, decreased from 16.7 to 14.3 ¿mol/L with MSM treatment (p=0.010).

"This pilot study showed that MSM 3 g bid for 12 weeks improved pain and physical function in patients with knee OA pain without major adverse events," the researchers concluded.

Similar benefits have been reported earlier by Usha and Naidu, who concluded in a study of 118 patients that MSM significantly decreased pain in knee OA and that combined MSM/glucosamine was even more effective [ 2 ].

Although MSM proponents and marketers unfailingly emphasize that MSM is a naturally occurring compound, the formulation used in this trial (as in all other human trials and case series reports) is not the least bit "natural." All of the marketed and tested MSM products are industrially produced by processing of dimethyl sulfoxide (DMSO), of which MSM is a metabolite. The resulting MSM retains many DMSO therapeutic effects but without DMSO's unfortunate tendency to make those who use it smell like garlic and oysters.



  1. Kim L, Axelrod L, Howard P, et al. Efficacy of methylsulfonylmethane (MSM) in knee osteoarthritis pain: a pilot clinical trial. American Association of Naturopathic Physicians 20th annual meeting; August 24-27, 2005; Phoenix, AZ.

  2. Usha PR, Naidu MUR. Randomized, double-blind, parallel, placebo-controlled study of oral glucosamine, methylsulfonylmethane and their combination in osteoarthritis. Clin Drug Invest 2004; 24:353-363.



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