It occurs naturally in some primitive plants, is present in small amounts in many foods and beverages, and is marketed (under the MSM name) as a dietary supplement.

Methylsulfonylmethane is marketed as a dietary supplement with medical claims ranging from anti-inflammatory effects for pain management, skin condition and aging treatments, and immune system modulation.

[citation needed][12] Small studies of MSM have suggested some benefit for treatment of oxidative stress and osteoarthritis, but evidence for other uses is lacking.

[citation needed] In July 2007 a manufacturer of MSM submitted a notification to the U.S. FDA claiming generally recognized as safe (GRAS) status.

The FDA responded in February 2008 with a letter of non-objection, functionally designating OptiMSM, the branded form of MSM, as GRAS.

[13][20] Nuclear magnetic resonance (NMR) studies have demonstrated that oral doses of MSM are absorbed into the blood and cross the blood/brain barrier.

The results from RCT showed broad improvements in facial skin hydration and elasticity, as well as decreased sebaceous secretions.

[34] Studies in animals indicate a hepatoprotective effect of MSM against several toxins including acetaminophen, paraquat, and carbon tetrachloride.

A 2004 multi-centered, open-label clinical trial found that MSM reduced both upper and lower respiratory symptoms associated with seasonal allergic rhinitis (SAR), and increased energy levels.

The study also evaluated an acute 12g dose and found significant improvements in all symptoms except itching eyes and sneezing, but not for PNIF.

The authors postulate that MSM’s anti-inflammatory properties reduce the overstimulation of inflammatory cells during exercise, thus conserving their ability to respond to infections threats.