The body uses glucosamine to build cartilage, the smooth covering of bone ends. Cartilage allows joints to move easily, without pain. Osteoarthritis is a painful condition, in which this cartilage becomes worn down. Many glucosamine supplements combine glucosamine with chondrotin sulfate. Chondrotin is produced naturally by the body, to lubricate joint surfaces and to prevent the breakdown of cartilage. However, the body does not effectively absorb ingested chondrotin, so supplementing with it may have no benefit. In several short-term studies, glucosamine has been found as effective as ibuprofen, in reducing osteoarthritis pain.


Athletes use glucosamine supplements in an effort to prevent breakdown of cartilage, ligaments, and tendons.


Glucosamine appears to be well tolerated by the body. Infrequent reports of side effects, include:

  • Stomach pain.

  • Rapid heart rate (tachycardia).

  • Swelling of the feet (edema).

  • Headache.

  • Skin rash.

  • Drowsiness.

  • Nausea.


Glucosamine is often advised as a 500-mg pill, taken three times a day. No known interactions with other drugs exist. Glucosamine supplementation does not seem to benefit everyone. If no benefits are seen within 6 to 12 weeks, the drug is not likely to be of benefit. A 3-week supply of glucosamine costs about $25. It is well absorbed, when taken by mouth.


Although glucosamine has been shown to help arthritis, and has relatively low risk of side effects, the Arthritis Foundation does not recommend glucosamine supplementation. Currently, no long-term studies have been performed. Almost all studies have involved small numbers of patients. Good studies looking at safety and best dosage have not been performed. Glucosamine has not been shown to protect joints from wear, as it is often advertised. It has not been shown to effect tendons or ligaments. It has not been shown to reverse arthritis.