Over the past 10 years, general practitioners and rheumatologists have commonly prescribed glucosamine and chondroitin supplements to relieve joint pain in patients. Many patients buy the supplements over-the-counter. In 2008, $2 billion worth of glucosamine supplements were sold worldwide — a 60% increase from 2003.

However, in a surprising new study published in this week’s issue of BMJ, researchers wrote that the supplements do not appear to relieve symptoms.

Glucosamine and chondroitin are typically taken in combination or separately to reduce osteoarthritis pain, particularly in the knees and hips. Researchers from Switzerland carried out a large scale review of studies that examined the efficacy of glucosamine and chondroitin.  Ten published trials consisting of over 3,800 patients with diagnosed osteoarthritis of the knee or hip were assessed.

Findings showed no clinically relevant effect of glucosamine and chondroitin on reducing joint point or reducing the narrowing of joint space — used in combination or alone. Simply put: They did not work.

Some patients continue to insist that the supplements work. Have you prescribed either or both to patients and observed a significant benefit?