The MSM (by OptiMSM), used in the manufacture of DynaMSM complies with the requirements of the latest United States Pharmacopeia/National Formulary.
It is the only MSM that has been critically evaluated as GRAS Certified (Generally Recognized as Safe) by the US FDA. (See table.)

Ingredients: Methylsulfonylmethane, Colloidal Silicon Dioxide (as absorbent), Magnesium Stearate (as lubricant), Hard Gelatin (capsule).