Dimethyl sulfoxide (DMSO) is a clear odorless liquid, inexpensively produced as a by-product of the paper industry. It is widely available in the USA as a solvent but its medical use is currently restricted by the FDA to the palliative treatment of interstitial cystitis and to certain experimental applications. In medicine, DMSO is also used as a topical analgesic, a vehicle for topical application of pharmaceuticals, as an anti-inflammatory, and an antioxidant.

DIMETHYL SULFONE is a compound that contains sulfur. It is a naturally occurring organosulfur compound utilized as a complementary and alternative medicine (CAM) under a variety of names including dimethyl sulfone, methyl sulfone, sulfonylbismethane, organic sulfur, or crystalline dimethyl sulfoxide. Its most common use is as anti-inflammatory agent. DIMETHYL SULFONE has been claimed to relieve stress, relieve pain, treat parasitic infections, increase energy, boost metabolism, enhance circulation, and improve wound healing, but there is little supporting scientific evidence. Due to its enhanced ability to penetrate membranes and permeate throughout the body, the full mechanistic function of MSM may involve a collection of cell types and is therefore difficult to elucidate. DIMETHYL SULFONE is recognized as safe by the FDA, but efficacy has yet to be proven. In rats, no adverse events were observed after daily doses of 2 g MSM per kg of body weight. Published clinical trials of DIMETHYL SULFONE did not report any serious side effects, but long-term effects are unknown.

Dimethyl fumarate (DMF) is the methyl ester of fumaric acid. DMF was initially recognized as a very effective hypoxic cell radiosensitizer. Later, DMF combined with three other fumaric acid esters (FAE) was licensed in Germany as oral therapy for psoriasis (trade name Fumaderm). Phase III clinical trials found that DMF (BG-12) successfully reduced relapse rate and increased time to progression of disability in multiple sclerosis (trade name Tecfidera). DMF is thought to have immunomodulatory properties without significant immunosuppression. The mechanism of action of dimethyl fumarate in multiple sclerosis is not well understood. It is thought to involve dimethyl fumarate degradation to its active metabolite monomethyl fumarate (MMF) then MMF up-regulates the Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathway that is activated in response to oxidative stress. Dimethyl fumarate is marketed under the brand name Tecfidera.