Is All Glucosamine Alike? Clarifying the Controversies for Product Selection and Clinical Research

In the United States, glucosamine is marketed as a dietary supplement therefore subject to less stringent manufacturing, labeling and marketing regulations than pharmaceuticals. The glucosamine product selected for the NIH-sponsored Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) was required to satisfy Investigational New Drug (IND) application (and therefore pharmaceutical manufacturing requirements). This review describes the procedure that was developed by the authors to identify a high-quality glucosamine product for GAIT and to clarify confusing product information and nomenclature.Proprietary glucosamine products and bulk glucosamine powders of various salt forms were evaluated. Both the published literature and information provided by suppliers of bulk glucosamine powders were evaluated. No proprietary glucosamine product was selected due to manufacturing practices that did not meet the pharmaceutical standards mandated by GAIT; i.e., no practices that control and document the quality issues of product purity and content variability. At the time this study was initiated dietary supplements were not required to meet these standards. Other problems identified with proprietary products included the presence of other dietary supplements and/or trace elements and the inability of a manufacturer to provide the appropriate quality of product within the time constraints of the study. A bulk powder of glucosamine hydrochloride was identified and capsules were manufactured for the trial in compliance with pharmaceutical Good Manufacturing Practices.