Also known as: Methylsulfonylmethane, Dimethyl sulfone, Organic sulphur, OptiMSM
Joint & ConnectiveGood evidence
An organic sulphur compound found in small amounts in food, used for joint comfort and exercise recovery. Cheap, well tolerated, and with better evidence than its low profile suggests.
Typical dose
1500.0–6000.0 mg per day
Split across the day, with food
What it is
Methylsulfonylmethane is a sulphur-containing compound that occurs naturally in small amounts in fruit, vegetables, grains and milk, and is part of the natural sulphur cycle in the environment.
It supplies bioavailable sulphur, which the body uses for building connective tissue proteins and for producing glutathione. Sulphur is not usually thought of as a nutrient of concern, but it is required in surprising quantities.
MSM is chemically related to DMSO, an industrial solvent used topically in some contexts. MSM is the oxidised form and is a stable, odourless white powder with none of DMSO's characteristics. The two are frequently confused and should not be.
How it works
MSM supplies sulphur for the synthesis of connective tissue components including collagen and glycosaminoglycans, and for glutathione, the body's principal internal antioxidant.
It has documented effects on inflammatory signalling, including on NF-kB, and on the production of inflammatory messengers. This is the more likely explanation for the effects on soreness and joint comfort than simple substrate supply.
There is also reported influence on oxidative stress markers after demanding exercise, which fits the glutathione connection and the recovery findings.
What the evidence shows
Joint comfort is the most studied area, with several controlled trials reporting improvements in comfort and physical function scores over 12 weeks. Trial sizes are modest but the direction is reasonably consistent.
The exercise recovery research is more interesting for this audience. Trials have reported reduced muscle soreness and lower markers of muscle damage and oxidative stress following demanding exercise, which is a more directly relevant finding than the joint work.
Overall the evidence is better than MSM's low profile suggests, though effect sizes are modest and independent replication is thinner than for the headline ingredients in this category. Given how cheap and well tolerated it is, the risk-to-reward comparison is favourable.
Dosing
Typical range is 1.5 to 6 g daily, split across servings. Joint trials have generally used 3 to 6 g; exercise recovery trials often 3 g.
Start at the lower end and build. Digestive upset is the main limiting factor and is largely a matter of ramping up rather than starting at 6 g.
Take with food. MSM is a fine white powder that dissolves easily but has a slightly bitter taste. It is frequently combined with glucosamine and chondroitin, though it has a reasonable evidence base of its own and does not need to be bought as part of a blend.
At a glance
Common forms
MSM powder, OptiMSM (distilled), Capsules, Combined with glucosamine and chondroitin
Half-life / duration
Effects on soreness reported within days; joint effects accrue over 12 weeks
Timing
Split across the day, with food
Competition status
Permitted — not on the WADA Prohibited List
Category
Joint & Connective
Safety and side effects
MSM has an excellent tolerability record. Trials report few adverse effects, and those reported are mild: digestive upset, bloating, headache and occasional skin reactions, mostly at higher doses or when starting too high.
Building the dose up gradually rather than starting at the top of the range resolves most of it.
Long-term data beyond the durations used in trials is limited. Speak to your doctor before use if you take regular medication, particularly anything affecting blood clotting.
Who should avoid it
Speak to your doctor before use if you take regular medication, particularly anything affecting blood clotting. Build the dose gradually to limit digestive upset. Not established at supplemental doses in pregnancy or breastfeeding.
This entry is provided for information only. Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle. Consult a qualified healthcare professional before use if you are pregnant, breastfeeding, taking medication or under medical supervision.
