It is a naturally occurring chemical found in the human body. It is in the fluid around joints. Additionally it exists in other places in nature.

There are different forms of it including glucosamine sulfate,  hydrochloride, and N-acetyl glucosamines.      These different chemicals have some similarities, but they may not have the same effects when taken as a dietary supplement. Most of the scientific research on it has involved glucosamine sulfate.

How does it work?

Joints are cushioned by the fluid and cartilage that surround them. In some people with osteoarthritis, the cartilage breaks down and becomes thin.     This results in more joint friction, pain, and stiffness. Researchers think that taking its supplements may either increase the cartilage and fluid surrounding joints or help prevent breakdown of these substances, or maybe both.

Some researchers think the “sulfate” part of it is also important. Sulfate is needed by the body to produce cartilage.     . These other forms do not contain sulfate.