Seniors  |  Herbals and supplements  |  Medicines

What You Need to Know about Glucosamine

The Bottom Line

Glucosamine is a natural substance found in cartilage. In the US, it is sold as a dietary supplement and promoted to reduce osteoarthritis pain. It is generally safe and well-tolerated. However, strong scientific evidence showing that it actually works is lacking and dietary supplements are not regulated in the same rigorous manner as medications.

The Full Story

Osteoarthritis is a painful joint disorder that affects about 27 million adults in the US. It is the most common type of arthritis. Osteoarthritis occurs when cartilage, the tissue that cushions the ends of the bones in the joints like the knee and the hip, wears away either from injury or normal wear and tear. Without the smoothness and cushion of the cartilage, the joint becomes painful, swollen, and stiff.

Glucosamine is a natural sugar found in cartilage. It can be harvested from the shells of shellfish (e.g., shrimp, lobster) or produced synthetically in a laboratory. In the US, glucosamine is sold as a dietary supplement. It is marketed and used widely to help decrease pain related to osteoarthritis and to slow the wearing down of cartilage in humans and animals. It is frequently found in combination with chondroitin. It is claimed that glucosamine and chondroitin serve as components for the building blocks of cartilage. While adults taking glucosamine are usually advised to take 500 mg three times a day, there is no standard dosage recommendation.

There are three important factors to consider before taking glucosamine: 

  • Glucosamine is a dietary supplement, not a medicine. As a supplement, its effectiveness, safety, and labeling are not regulated by the Food and Drug Administration. Some glucosamine products have been found to contain less or more glucosamine than was listed on the label. In other cases, the product was found to be contaminated.
  • Consistent, strong, and definitive evidence for the effectiveness of glucosamine, alone or in combination with chondroitin, is lacking. The overall thought seems to be that glucosamine might be helpful in lessening osteoarthritis pain or it might make no difference at all.
  • Glucosamine has been shown to be safe and well-tolerated. Common side effects are nausea, vomiting, abdominal pain, and diarrhea. There is a risk for severe and life-threatening allergic reactions to glucosamine in people with shellfish allergy or those with asthma.

Poison Control often receives calls for guidance when a child gets into a family member’s bottle of glucosamine (or a tablet from the dog’s food bowl!) or when someone unintentionally took their glucosamine twice. In general, people fare well with these small, unintentional ingestions.

Before taking glucosamine, talk to your doctor and be sure it is safe and appropriate for you. Always tell your doctor and pharmacist about any supplements you are taking just as you would with your prescription and over-the-counter medications. As with all home and health products, keep the bottle out of reach of children and pets.

If you suspect an adverse reaction to glucosamine, are concerned about an unintentional overdose, or have a child who might have swallowed some glucosamine tablets, immediately check the webPOISONCONTROL® online tool or call Poison Control at 1-800-222-1222 for guidance.

Serkalem Mekonnen, RN, BSN, MPH
Certified Specialist in Poison Information


For More Information

Glucosamine sulfate [internet]. Bethesda MD: MedLinePlus: US National Library of Medicine – National Institutes of Health; 2016. [accessed Sept 3, 2016] 

Questions and answers: NIH glucosamine/chondroitin arthritis intervention trial primary study [internet].Bethesda MD: National Center for Complementary and Integrative Health – National Institutes of Health; 2016. [accessed Sept 3, 2016] 

Dietary supplements [internet]. Silver Spring MD: US Food and Drug Administration; 2016. [accessed Sept 3, 2016] 

For Pet Owners

Overdoses of oral chondroprotective agents [internet]. New York: ASPCA. [accessed Sept 2, 2016] 


References

Erickson J, Messer TM. Glucosamine and chondroitin sulfate treatment of hand osteoarthritis. J Hand Surg Am 2013;38:1638-40.

Lee YH, Woo JH, Choi SJ, Ji JD, Song GG. Effect of glucosamine or chondroitin sulfate on the osteoarthritis progression: a meta-analysis. Rheumatol Int 2010;30:357-63.

Matheu V, Gracia Bara MT, Pelta R, Vivas E, Rubio M. Immediate-hypersensitivity reaction to glucosamine sulfate. Allergy 1999;54:643.

McAlindon TE, LaValley MP, Gulin JP, Felson DT. Glucosamine and chondroitin for treatment of osteoarthritis: a systematic quality assessment and meta-analysis. JAMA 2000;283:1469-75.

Questions and answers: NIH glucosamine/chondroitin arthritis intervention trial primary study [internet].Bethesda MD: National Center for Complementary and Integrative Health – National Institutes of Health; 2016. [accessed Aug 29, 2016] 

Poisoned?

Call 1-800-222-1222 or

HELP ME online

Prevention Tips

  • Before taking glucosamine, talk to your doctor and be sure it is safe and appropriate for you.
  • Always tell your doctor and pharmacist about any supplements you are taking, just as you do with your prescription and over-the-counter medications.
  • Keep the bottle out of reach and sight of children or pets.
  • Use only USP-Verified supplements.

This Really Happened

A 2-year-old girl was able to reach a bottle of glucosamine and chondroitin, and her mother found her with some tablets in her mouth. The mother was concerned and took her to an ER.

A nurse practitioner in the ER called Poison Control for treatment recommendations. Poison Control informed the nurse practitioner that the child would need to swallow a very large number of tablets for there to be concern for toxic effects. The mother was reassured and the child was allowed to go home.

Poison Control called the mother at home to follow-up on the child. The child was well and no adverse effects occurred.