500 mg is the average size of a single capsule of any herb or Tylenol. MSM is now readily sold all over in health food stores. MSM is also like the herbs example. Otherwise you might as well just through your money away. MSM is considered very safe.
Toxicity is extremely rare.
MSM is generally non-allergenic. Incorporation of methylsulfonylmethane sulfur into guinea pig serum proteins. The cystine content of the finger nails in arthritis. I spoke about earlier in this write up. The father John Rich passed away in 1997.