Other name(s):

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

General description

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

It is found in chitin. This is a fibrous material.It makes up the outer shells of shellfish and insects.

Medically valid uses

A small study found that glucosamine helped knee pain when taken with chondroitin. It did this 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. Experts say more studies are needed. 

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

Unsubstantiated claims

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

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

Dosing format

Large amounts of glucosamine aren’t in food sources. You have to take it as a supplement. The advised dose is 400 mg to 500 mg taken 3 times a day. Higher doses may be used to ease arthritis.

Glucosamine comes with other substances. It may come with chondroitin sulfate. Or it may come with manganese ascorbate.

Side effects, toxicity, and interactions

Glucosamine causes fewer side effects than other medicines used to treat arthritis. But it can still cause side effects. These can include:

• Mild gastrointestinal problems

• Drowsiness

• Skin reactions

If you have diabetes, talk to your healthcare provider before taking glucosamine. It may make insulin resistance worse. This is a greater risk with high doses.

If you’re taking a blood thinner such as warfarin, don't take glucosamine. It may increase the effects of warfarin. This may thin your blood too much. This can raise your risk of bruising and bleeding.

If you are pregnant or breastfeeding, talk to your healthcare provider before taking any supplements.