An Under-Reported Story about the NIH Study

Finally, the long-awaited results of the National Institutes of Health Glucosamine/Chondroitin Arthritis Intervention Trial (NIH GAIT) have been reported – and although the facts are favorable, the news media have presented a confusing story and often overlooked the positive data regarding the effectiveness of Glucosamine and Chondroitin (abbreviated GC) supplements

“No better than Placebo?” Here’s what the news reports omitted:

There were five groups – Glucosamine only, Chondroitin only, Glucosamine plus Chondroitin combination, Celebrex® and Placebo (dummy pill). Doses matched the typical amounts used in dietary supplement products. It is important to keep in mind that all subjects had access to as much Tylenol® as they wanted to control pain (this is called rescue medication). It turned out that the subjects took 1-2 pills of Tylenol® daily, which should take care of mild pain.

The results showed that Tylenol® did take care of mild pain as the Placebo group showed fantastic results (60% of the subjects reduced their pain by 20% or more). As a result, the supplement groups, although numerically better than Placebo, were not statistically different from the Placebo group for reduction in pain.

Here’s the bottom line: the more you hurt, the more effective GC supplements are:

Importantly, the NIH GAIT study results were positive for the combination of Glucosamine and Chondroitin Sulfate in persons with moderate-to-severe knee pain from osteoarthritis. GC produced large and significant decreases in pain over the Placebo group. In fact, in the group of subjects with moderate-to-severe knee pain, Celebrex® did not significantly decrease pain compared to the Placebo group. In other words, GC outperformed Celebrex®. In addition, measurements of joint function and mobility were significantly improved in the GC group, but not in the Celebrex® or other supplement groups.


This large-scale study of osteoarthritis knee pain cost $12.5 million dollars and was started in 1998, and it is still not finished. About half of the patients are being followed for another year to look at a measurement beyond just pain relief: to see if Glucosamine/Chondroitin (GC) supplements can actually slow, stop or reverse joint cartilage loss (as seen by several European studies). Results from this part of the study should be available by November 2006. Stay tuned…



Tylenol® is a registered trademark of The Tylenol Company.
Celebrex® is a registered trademark of G.D. Searle LLC.