Description: April 16, 2007 -- Chondroitin, a dietary supplement, works no better than a sugar pill, analysis of clinical data suggests.

In the U.S., chondroitin is almost always combined with glucosamine, another supplement. Annual U.S. sales of the chondroitin/glucosamine combination were $810 million in 2005, according to figures cited by the Council for Responsible Nutrition (CRN), a supplement industry trade group.

And sales "continue to grow at a phenomenal pace," Andrew Shao, PhD, the CRN's vice president for scientific and regulatory affairs, tells WebMD. Shao says only omega-3 supplements sell faster than chondroitin-based supplements.

"Sales continue to grow. This is presumably because consumers are finding a benefit," Shao says.

That benefit appears to be an illusion, suggests Peter Juni, MD, head of clinical epidemiology and biostatistics at the University of Bern in Switzerland.

David T. Felson, MD, MPH, professor of medicine and epidemiology at Boston University, uses stronger la