Glucosamine and Chondroitin

What Are These Supplements?

Glucosamine and chondroitin are substances naturally found in cartilage. They're commonly taken as supplements for osteoarthritis, with the theory that they help maintain or rebuild cartilage. They're often sold together.¹

Types of Glucosamine

Glucosamine sulfate - Most studied
Glucosamine hydrochloride - More concentrated
N-acetyl glucosamine - Different form
Sulfate form generally preferred

What the Evidence Shows²

Mixed results in studies
Some positive trials (mostly glucosamine sulfate)
Large NIH study showed modest benefit for subset
May help some people modestly
Unlikely to rebuild cartilage
Generally safe to try

Dosing

Glucosamine: 1500 mg/day (can divide doses)
Chondroitin: 800-1200 mg/day
Often sold in combination products
May take 2-4 months to see effects

Safety³

Generally well tolerated
Mild GI upset possible
Usually derived from shellfish (allergies)
May interact with blood thinners
May affect blood sugar (diabetics monitor)

Who Might Consider

Mild to moderate osteoarthritis
Want to try before other treatments
Looking for lower-risk options
Willing to give 3+ months trial

Bottom Line

Evidence is mixed but they're generally safe. Some people report benefit. Consider a 3-month trial if interested.

References

Clegg DO, Reda DJ, Harris CL, et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med. 2006;354(8):795-808.
Wandel S, Jüni P, Tendal B, et al. Effects of glucosamine, chondroitin, or placebo in patients with osteoarthritis of hip or knee. BMJ. 2010;341:c4675.
Henrotin Y, Mobasheri A, Marty M. Is there any scientific evidence for the use of glucosamine in the management of human osteoarthritis? Arthritis Res Ther. 2012;14(1):201.