Information provided by the National Center for Complementary and Alternative Medicine (NCCAM):
1.The majority of research has found little effect of glucosamine or chondroitin on symptoms or joint damage associated with osteoarthritis of the knee or hip. Studies have found that glucosamine and chondroitin supplements may interact with the anticoagulant (blood-thinning) drug warfarin (Coumadin). But overall, studies have not shown any other serious side effects.
2.Dimethyl Sulfoxide (DMSO) and Methylsulfonylmethane (MSM) are two chemically related dietary supplements that have been used for arthritic conditions; however, evidence does not suggest that DMSO and MSM are helpful for osteoarthritis symptoms. Although there are limited safety data available, some side effects from topical DMSO have been reported, including upset stomach, skin irritation, and garlic taste, breath, and body odor. Only minor side effects are associated with MSM in humans including allergy, upset stomach, and skin rashes.
3.S-Adenosyl-L-methionine (SAMe) is a molecule that is naturally produced in the body and is often taken as a dietary supplement; however, there is not enough evidence to support the use of SAMe for osteoarthritis of the knee or hip. SAMe is generally considered safe, but common side effects include gastrointestinal problems, dry mouth, headache, sweating, dizziness, and nervousness.
4.There is preliminary evidence that avocado/soybean unsaponifiables (ASU), supplements made from avocado oil and soybean oil extracts, may have modest beneficial effects on symptoms of osteoarthritis. Safety information has not been sufficiently available.
5.Although some results suggest that a few herbs may be beneficial for OA symptoms, the overall evidence is weak, and conclusions among reviews of the literature provide conflicting interpretations. In general, herbs have not been studied or prepared in a consistent way. There is also a general lack of safety data available.
6.If you take, or are considering taking, dietary supplements for osteoarthritis, tell your health care providers. They can do a better job caring for you if they know what dietary supplements you use.
From NCCAM.NIH.gov