March 07, 2019


Other name(s):

chitosamine, 2-amino-2deoxy-D-glucose

General description

Glucosamine is a natural substance. It may ease symptoms of osteoarthritis.

Glucosamine is found in chitin. This is the fibrous material that makes up the outer skeleton of shellfish and insects. It’s found in mucoproteins and mucopolysaccharides. These are made by many animals.

Medically valid uses

An initial 6 month clinical trial found that glucosamine, when taken with chondroitin, decreased knee pain in people with moderate to severe arthritis. It led to less pain relief for those with mild pain. But the number of people in the study was small. Researchers say more studies are needed. 

It isn’t known exactly how glucosamine works to treat arthritis. But there are some theories. Some studies suggest that it’s needed to help make glycosaminoglycans and hyaluronic acid. Large amounts of glucosamine may increase how much of these substances your body makes. These substances are needed for joint cartilage and synovium. When taken by mouth, glucosamine builds up in the cartilage of the joints.

Unsubstantiated claims

There may be benefits that have not yet been proven through research.

Glucosamine may help prevent joint overuse symptoms. It may reduce symptoms of temporal mandibular joint (TMJ) disease.

Dosing format

The suggested dose of glucosamine is 400 mg to 500 mg taken 3 times a day. Higher doses are sometimes used to ease arthritis symptoms.

Large amounts of glucosamine aren’t in normal food sources. You’d have to take it as a supplement.

Glucosamine sulfate comes with other materials. These can include chondroitin sulfate or manganese ascorbate.

Women who are pregnant or breastfeeding should talk to their healthcare providers before taking any supplements.

Side effects, toxicity, and interactions

Glucosamine causes fewer side effects than other arthritis medicines. But it can still cause side effects. These can include mild gastrointestinal problems, drowsiness, and skin reactions.

People with diabetes should talk to their healthcare providers before taking glucosamine. It may make insulin resistance worse. This is a greater risk with high doses.

If you’re taking blood thinners such as warfarin, don't take glucosamine. It may increase the blood thinning effects of warfarin. This can increase your risk of bruising and bleeding.


March 07, 2019


Pharmacologic therapy of osteoarthritis. UpToDate.

Reviewed By:  

Diane Horowitz MD,Rita Sather RN,Cynthia Godsey