How Much Glucosamine Chondroitin Should You Take?

Glucosamine is a dietary supplement that is often combined with another supplement, chondroitin, to treat osteoarthritis. Glucosamine is made from the shells of shellfish and chondroitin is derived from cow trachea. Evidence published in the New England Journal of Medicine has suggested that glucosamine alone or combined with chondroitin can help relieve osteoarthritis pain in a subgroup of people with moderate to severe knee osteoarthritis.

Treatment Recommendations

Supplements advertised for improved joint health can be confusing and even downright misleading. Because supplements don't undergo the rigorous testing that pharmaceutical drugs do, the "recommended" dose is less supported by hard clinical evidence. And that can be a problem.

If you take too little, you won't achieve a beneficial effect and you are essentially wasting your money. If you take too much, you may be increasing the risk of side effects. Results of a study from Tufts-New England Medical Center conclude that typical doses listed on over-the-counter supplements are probably not strong enough to help relieve arthritic joint pain and stiffness.

To this end, the recommended dosages are based more on what amount of drug causes little to no harm yet is believed to offer therapeutic benefits. Many health experts today endorse a staged approach in which a higher initial (loading) dose is used to test whether benefits are achieved, followed by a lower maintenance dose if and when the benefits are felt.

The initial dose is typically 1,500 (milligrams) mg of glucosamine and 1,200 mg of chondroitin daily for one to two months. If a response is obtained, the dose can be reduced to 1,000 mg or glucosamine and 800 of chondroitin per day.

According to the Tufts study, it is still unclear as to whether higher doses are more effective and whether that level of dosing may cause potential harms.

Considerations and Risks

Potential side effects of glucosamine chondroitin
Illustration by Cindy Chung, Verywell

Because supplements are not regulated by the U.S. Food and Drug Administration (FDA), the amount of active ingredient cannot be verified. To ensure the safest possible use, it is best to use a brand name supplement like Cosamin DS (glucosamine plus chondroitin) or DONA (glucosamine) for at least two months before switching to a less expensive product.

Most studies, in fact, have shown that glucosamine needs to be taken for two to four months before its full benefits are realized, although some will experience improvement sooner.

Potential side effects of glucosamine-chondroitin include:

  • Nausea
  • Diarrhea
  • Constipation
  • Stomach pain
  • Gas and bloating
  • Puffy eyes
  • Hair loss

These risks may increase at higher doses. Glucosamine should be avoided if you are allergic to shellfish, and some reports suggest that the supplement may elevate blood sugar levels in diabetics. People on the blood thinner Coumadin (warfarin) may have an increased risk of bleeding.

When to Call a Doctor

Stop treatment and call your doctor if you experience sudden swelling in the legs or irregular heartbeats. Call 911 or seek emergency care if you develop hives, shortness of breath, rapid heartbeats, or the swelling of the face, tongue, or throat.

A Word From Verywell

Despite this advice from two well-respected doctors, always consult your own doctor. Your doctor knows your medical history and knows your current medication regimen. Make your doctor aware that you wish to add a supplement to your treatment regimen. Then, follow your doctor's advice.

It should be noted that the American Academy of Orthopaedic Surgeons currently advises against the use of glucosamine sulfate, chondroitin sulfate, and glucosamine hydrochloride in treating symptomatic knee osteoarthritis.

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