Clinical inquiries: Do glucosamine and chondroitin worsen blood sugar control in diabetes?

Despite theoretical risks based on animal models given high intravenous doses, glucosamine/chondroitin (1500 mg/1200 mg daily) does not adversely affect short-term glycemic control for patients whose diabetes is well-controlled, or for those without diabetes or glucose intolerance (SOR: A, consistent, good-quality patient-oriented evidence). Some preliminary evidence suggests that glucosamine may worsen glucose intolerance for patients with untreated or undiagnosed glucose intolerance or diabetes (SOR: C, extrapolation from disease-oriented evidence). Long-term effects are unknown; however, no compelling theoretical or incidental data suggest that long-term results should be different (SOR: C, expert opinion). Further studies are required to clarify the effects of glucosamine on patients with poorly controlled diabetes or glucose intolerance.