March 01, 2021

Are glucosamine and chondroitin effective and safe for osteoarthritis?

Q: I have osteoarthritis in my knees and am curious about supplements like glucosamine and chondroitin. Are these safe and effective for osteoarthritis?

A: Along with standard treatments for osteoarthritis — including low-impact exercise, loss of excess weight, physical therapy, cortisone injections and nonprescription pain medications — a number of supplements are available. These include glucosamine, chondroitin, methylsulfonylmethane (MSM) and S-adenosyl-L-methionine (SAMe).

When you have osteoarthritis, the cartilage that covers the ends of your bones to help joints move smoothly wears down over time. Glucosamine is a natural compound found in your cartilage. There are several forms of supplemental glucosamine, but the most encouraging evidence is for glucosamine sulfate. Even so, this evidence is mixed, but glucosamine might provide some pain relief for knee osteoarthritis. Some studies have shown that it may relieve osteoarthritis pain as well as do some nonsteroidal anti-inflammatory drugs (NSAIDs).

The supplement SAMe also may be helpful. There is research that shows that SAMe relieves osteoarthritis symptoms as well as NSAIDs do and produces fewer side effects.

There isn't as much research to support the use of either MSM or chondroitin. Some studies of MSM have shown slight improvements in arthritis symptoms, but these studies were small and looked only at a brief period. Chondroitin may provide modest pain relief from osteoarthritis, although study results conflict.

Some research suggests that taking chondroitin and glucosamine together works better than taking either alone. It's common to find the two ingredients together in a single supplement.

All of these supplements come with the potential for side effects, such as gastrointestinal discomfort, and some may interact with drugs such as antidepressants, blood pressure medications and blood thinners. These supplements may...