Glucosamine is a natural component found in healthy cartilage tissue. Glucosamine can be taken as an over-the-counter supplement as is available in most drug and health food stores. The Mayo Clinic reports that as a supplement, glucosamine claims to help improve joint mobility, decrease inflammation and reduce pain in conditions like osteoarthritis and rheumatoid arthritis. While some research shows promising outcomes of the use of glucosamine on providing some relief from osteoarthritis, much more information is needed in order to make a definitive ruling on its effectiveness. Glucosamine is not regulated by the U.S. Food and Drug Administration, so there are no guarantees of its strength, purity, safety or effectiveness. Anyone interested in taking glucosamine for joint health should consult their doctor first.

Allergy To Shellfish

According to the Mayo Clinic, anyone with an allergy to shellfish should avoid taking glucosamine. This is due to the fact that glucosamine is derived from the shells of shrimp, crab, lobster and other shellfish. The Mayo Clinic notes that serious hypersensitivity reactions have been noted with the use of glucosamine, though such reactions are rare. Anyone with an allergy to shellfish should contact his physician prior to taking glucosamine.

Pregnancy or Nursing Mothers

The Mayo Clinic reports that pregnant women and nursing mothers should not take glucosamine due to a lack of scientific data regarding its effects on unborn babies and infants.

Diabetes or Other Blood Sugar Problems

Spine Health reports that diabetic patients should use caution when taking glucosamine because some studies have suggested that glucosamine may cause insulin resistance 1. Medline Plus reports that some studies have shown that when taken in pill form, glucosamine has no effect on insulin, but when taken by injection, glucosamine may cause insulin resistance. Anyone who needs to check their blood sugars on a regular basis should check with their physician prior to taking glucosamine.

Risk For Bleeding

The Mayo Clinic notes that glucosamine may increase the risk for spontaneous bleeding. Anyone taking a medication such as blood thinners or anyone who has been diagnosed with a bleeding disorder should consult their doctor prior to taking glucosamine.