What it is
MSM (dimethyl sulfone) is an organosulfur compound present in small amounts in fruits, vegetables, grains, coffee, tea, beer and cow's milk. The supplement is synthetic, obtained by oxidizing DMSO and then purified by distillation or crystallization. People buy it for osteoarthritis, joint pain, recovery and, under the name "organic sulfur", for skin, hair and nails.
What the label does not say
- The knee data come down to two 12-week trials: 50 people at 6 g per day (WOMAC pain and function improved, stiffness not, and authors who write that long-term benefit and safety cannot be confirmed by this pilot), then 49 people at 3.375 g per day (function improved, pain not significant, improvements described as small and of clinical significance still to be established).
- The 2008 systematic review concludes that the data are "positive but not definitive" for mild to moderate knee osteoarthritis, on 52 patients on MSM in total, with uncertainty about the optimal dose and duration.
- The "organic sulfur" argument has no clinical translation: the 2017 review notes that no dose-dependent trend appears in humans on plasma sulfate or homocysteine, and that the use of MSM's sulfur would depend on the microbiota. None of that measures skin, hair or nails.
- Health Canada limits the claim to "helps to relieve (joint) pain associated with osteoarthritis (of the knee)", caps it at 2,000 mg per dose and 6,000 mg per day, and asks you to take it with food and to avoid bedtime. Nothing on skin, hair, nails or recovery.
The forms on the shelf
- MSM on its own, as a powder or in capsules: the form used in the trials, at 3.375 g and 6 g per day.
- Combinations with glucosamine and chondroitin: the Canadian monograph requires 1,500 to 6,000 mg of MSM per day; the MSM figure in the blend is read against that range, not against the total of the ingredients.
- Origin: the source accepted by the monograph is synthetic dimethyl sulfone, whatever the wording on the label.
Published reference values
- Health Canada monograph: 1,500 to 6,000 mg per day, at most 2,000 mg per dose, "use for at least 4 weeks to see beneficial effects".
- Trial doses: 3.375 g and 6 g per day for 12 weeks.
- Tolerance: the 2017 review reports few adverse effects, mild, up to 4 g per day, and a GRAS notification in the United States below 4,845.6 mg per day; Health Canada warns of possible digestive discomfort.
- No recommended intake or upper limit.
When
With food and not at bedtime, according to the Canadian monograph, in split doses since each dose is capped at 2,000 mg. The effect, when it was measured, was measured at 12 weeks.
To mention to a professional
- Pregnancy and breastfeeding (Health Canada asks you to consult), symptoms that worsen. No drug interaction was found in the sources consulted, which reflects the scarcity of data more than established safety.
What it is sold for, and what the data show
MSM is sold as "organic sulfur" for joints, skin, hair, nails, inflammation and recovery. What exists: two 12-week trials on knee osteoarthritis, about a hundred participants in all, small gains and good tolerance. Nothing comparable was found for skin, hair, nails or athletic recovery.
From the plate first
Present in trace amounts in fruits, vegetables, grains, coffee, tea, beer and cow's milk, in quantities that bear no relation to the grams used in the trials.
Sources
- Health Canada, natural health product monograph, MSM (Methylsulfonylmethane)
- Health Canada, product monograph, Joint Health Products, Multiple Ingredient
- Butawan, Benjamin and Bloomer, Methylsulfonylmethane: Applications and Safety of a Novel Dietary Supplement, Nutrients (2017)
- Brien et al., Systematic review of the nutritional supplements dimethyl sulfoxide (DMSO) and methylsulfonylmethane (MSM) in the treatment of osteoarthritis, Osteoarthritis and Cartilage (2008)
- Kim et al., Efficacy of methylsulfonylmethane (MSM) in osteoarthritis pain of the knee: a pilot clinical trial, Osteoarthritis and Cartilage (2006, individual trial)
- Debbi et al., Efficacy of methylsulfonylmethane supplementation on osteoarthritis of the knee: a randomized controlled study, BMC Complementary and Alternative Medicine (2011, individual trial)
Educational information, drawn from the sources above. It does not replace the advice of a health professional, who remains the reference for your situation, your medications, pregnancy or breastfeeding.