Origin: Organic sulfur compound found naturally in fruits, vegetables, grains, animals and humans.

Dosage: Tablets, liquid, capsule or powder, topical and oral. Typically 1,000 mg to 3,000 mg daily with meals. 

Claims: Reduces pain and inflammation.

What we know: MSM is an organic sulfur compound. Sulfur is needed to form connective tissue. MSM also seems to act as an analgesic by lessening nerve impulses that transmit pain.

Studies: A 2006 pilot study of 50 men and women with knee osteoarthritis showed that 6,000 mg of MSM improved symptoms of pain and physical function without major side effects. No large, well-controlled hum­an studies have been performed.

 MSM may cause stomach upset or diarrhea. Don’t use MSM if you are taking blood thinners.