Glucosamine, Chondroitin and Collagen: What We Know

Walk into any pharmacy and you will find shelves full of joint supplements with glucosamine, chondroitin or collagen. Many people with sore knees try them, often on the advice of a friend. But what are these substances, and what does research actually say about them? This article gives a balanced overview. It does not recommend or reject any product: whether a supplement makes sense for you is a question for your doctor or pharmacist.

Glucosamine

Glucosamine is a substance that the body uses to build cartilage and other connective tissue. Supplements are often made from the shells of shellfish, although other sources exist, and they come in different forms. Research on glucosamine for knee osteoarthritis has been going on for many years. Some studies found a modest benefit for some people, while others found no clear difference compared with a placebo. Because the results are mixed, professional guidelines in different countries do not agree on whether to recommend it.

Chondroitin

Chondroitin is also a natural part of cartilage and is often sold together with glucosamine in one product. The picture is similar: some studies reported less pain or better function, others did not. Differences in product quality, dose and study design make the results hard to compare.

Collagen

Collagen is the main protein in skin, tendons, ligaments and cartilage, and collagen powders and capsules have become very popular. There are fewer and smaller studies on collagen for knee pain than on glucosamine, and their results are also mixed. It is important to know that the body breaks down collagen from food and supplements during digestion, so taking collagen does not mean it goes straight to your knee.

Safety points to discuss with your doctor

Many people take these supplements without problems, but they are not suitable for everyone. Talk to your doctor or pharmacist first if any of the following applies to you:

• you are allergic to shellfish, because many glucosamine products are made from shellfish,
• you take medicines that affect blood clotting, because interactions have been reported,
• you have diabetes or problems with blood sugar,
• you are pregnant or breastfeeding,
• you take other medicines or supplements regularly.

Keep in mind that in many countries supplements are not tested as strictly as medicines, so the content and dose can differ from product to product.

If you decide to try a supplement

• agree with your doctor on whether it makes sense for you and for how long you will try it,
• keep a simple diary of your pain and what you can do, so you can judge honestly whether anything changes,
• stop and seek advice if you notice stomach problems, a rash or other unwanted reactions,
• do not stop or change medicines your doctor prescribed without talking to them first.

What else helps the knees

Whatever you decide about supplements, many guidelines put regular exercise and a healthy body weight at the center of caring for sore knees. Strong thigh and hip muscles take load off the joint; our home strengthening exercises are a good place to start. Our articles on body weight and knee load and anti-inflammatory foods for your joints look at everyday habits, and the article knee osteoarthritis treatments gives an overview of medical options. A bamboo knee sleeve can be a pleasant everyday companion as well: it gives the knee warmth and a feeling of support while you stay active, although it does not treat the condition.

When to see a doctor

Do not rely on supplements if your knee is very swollen, red or hot, locks or gives way, or if the pain keeps getting worse. These signs need a medical check; read more in our article when knee pain is serious.

A sleeve you will actually wear

The best sleeve is the one that does not end up in a drawer. The KeenTrove Bamboo Knee Sleeve is made for exactly that:

• soft, breathable bamboo, comfortable even in summer
• fits snugly but does not dig in behind the knee
• does not lock the knee, so you move naturally
• wear it under your clothes during the day and in bed at night

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Note: this article is for information only and does not replace an examination by a doctor. If you have circulation problems or diabetes, or have recently had knee surgery, talk to your doctor before wearing compression.