There is evidence that glucosamine sulfate may provide pain relief, reduce tenderness, and improve mobility in patients with OA. Most of the current data, however, are derived from the European and Asian literature and there are no studies supporting the use of this agent in the US. The studies published to date have been done in small numbers of patients; adequate long-term trials examining the safety, efficacy, and optimal dosage requirements of glucosamine sulfate are lacking. Most of the available clinical data are difficult to interpret due to serious deficiencies in study design. Furthermore, studies evaluating the appropriate place of glucosamine sulfate in the therapeutic armamentarium of OA remain to be done.