What Does Glucosamine Chondroitin Do for Your Body?

Reviewed on 7/7/2022
A doctor checking a man's knee
Some research suggests glucosamine and chondroitin may help with osteoarthritis joint pain and stiffness, osteoarthritis of the jaw, chronic low-back pain and osteoarthritis of the spine, joint structure, osteoarthritis of the hand, and osteoarthritis of the knee or hip.

Glucosamine and chondroitin are structural components of cartilage, connective tissue that cushions the ends of the bones within joints. Both are produced naturally in the body and are also available as dietary supplements

The National Institutes of Health estimates 6.5 million adults, or 2.6% of the population, have used one or both of these supplements

Studies on the effectiveness of glucosamine and chondroitin are mixed, but some evidence suggests they may help with the following:

  • Osteoarthritis joint pain and stiffness
    • They may help relieve osteoarthritis joint pain and stiffness
    • There have been conflicting results on the use of glucosamine for osteoarthritis of the knee
      • One study showed evidence of improvement in a small subgroup of patients with moderate-to-severe knee pain who took glucosamine and chondroitin together
      • Some participants in European studies reported their knees felt and functioned better after taking glucosamine
      • It is unknown why results of studies differ: it might be due to the type of glucosamine used, the way it was administered, other differences in the way the studies were conducted, or chance
  • Osteoarthritis of the jaw
    • There are mixed results on glucosamine use for osteoarthritis of the jaw
    • One study showed participants had less pain than those given ibuprofen, but another study showed those taking glucosamine did no better than those who took a placebo 
  • Chronic low-back pain and osteoarthritis of the spine 
    • Glucosamine for chronic low-back pain and osteoarthritis of the spine does not seem to be beneficial and one study found participants who received glucosamine fared the same at six months as those who received placebo
  • Joint structure 
    • Chondroitin might help joint structure though glucosamine does not have beneficial effects on joint structure
  • Osteoarthritis of the hand 
    • Chondroitin may improve function and reduce pain for osteoarthritis of the hand
  • Osteoarthritis of the knee or hip
    • Chondroitin has generally not been shown to be helpful for pain from osteoarthritis of the knee or hip
    • The largest and best studies showed chondroitin doesn’t lessen osteoarthritis pain
    • The American College of Rheumatology (ACR) has not recommended glucosamine or chondroitin use for people with knee or hip osteoarthritis 
    • The National Center for Complementary and Integrative Health (NCCIH) says the evidence on glucosamine for osteoarthritis pain is unclear, and chondroitin isn’t helpful

Which Form of These Supplements is Best?

  • Some studies find chondroitin to better for osteoarthritis, while others find glucosamine is more advantageous, and yet others suggest a combination of the two. These two supplements are often packaged together.  
  • There are two main forms of glucosamine in supplements. Some studies show glucosamine sulfate is better and others find glucosamine hydrochloride to be superior, while one study that compared the two forms of glucosamine found no difference between them.   
  • Evidence generally suggests use of glucosamine sulfate for improved joint flexibility and range of motion, with or without chondroitin sulfate, for knee osteoarthritis.

What Are Side Effects or Risks of Glucosamine Chondroitin?

In general, glucosamine, chondroitin, or both rarely cause side effects and are well-tolerated. 

  • Glucosamine or chondroitin may interact with the blood thinner warfarin 
  • Glucosamine might affect the way the body handles sugar, especially in people who have diabetes or other blood sugar problems, such as insulin resistance or impaired glucose tolerance.
  • They may raise eye pressure and increase the risk of glaucoma
  • A study in rats showed long-term use of moderately large doses of glucosamine might damage the kidneys

Tell your doctor before taking glucosamine or chondroitin supplements. 

Reviewed on 7/7/2022