Glucosamine in osteoarthritis: questions remain.

Glucosamine is now widely used in the hope that it will relieve symptoms of osteoarthritis and stop its progression, yet studies have so far failed to prove convincingly that it works, how it might work, or whether it is safe to take long-term. This is an overview of the evidence to date for currently available glucosamine preparations, as well as for glucosamine used in combination with another popular nutraceutical, chondroitin sulfate.