Glucosamine supplements are a popular remedy for arthritis pain relief, especially for osteoarthritis. Unlike NSAIDs and other anti-inflammatory drugs, the pain relief provided by glucosamine lasts even after a person is no longer taking the supplements. This is because glucosamine helps repair damaged cartilage in joints. There has been some concern that glucosamine might cause insulin resistance and that people with diabetes should not take glucosamine.

This concern is because of previous animal and human studies that found “giving glucosamine can impair insulin’s action, which can potentially make [people] diabetic or worsen diabetes.” This is according to Rajaram J. Karne, now of the Ohio State University Medical Center in Columbus.

Most people take glucosamine orally, not by injection.

Karne and his collaborators in Bethesda, Md, at the National Center for Complementary and Alternative Medicine, tested a commonly used dose of oral glucosamine in 20 normal weight and obese adults. The dose they tested was three 500-milligram pills of glucosamine daily or a placebo.

Unlike the high doses of injected glucosamine used in previous studies, this oral dose of glucosamine is what is normally recommended by health care professionals and what is most commonly used by folks taking glucosamine supplements.

Six weeks of glucosamine didn’t make any measurable difference in insulin’s action.

This study indicates that at least in adults who don’t already have diabetes, three 500-milligram glucosamine pills does not effect insulin resistance or cause diabetes.
This dose should be safe for those taking it for osteoarthritis pain relief.