What Is Glucosamine?

Jillian Kubala, RD
·9 min read
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Medically reviewed by Suzanne Fisher, MS

Glucosamine is a substance that’s naturally produced by your body. It’s necessary for the production of proteoglycans and glycosaminoglycans, which are the building blocks of cartilage, a flexible connective tissue that protects your bones and joints.

Glucosamine supplements have anti-inflammatory effects and may help slow cartilage destruction, which may benefit people with certain health conditions, such as osteoarthritis.

Here’s what you need to know about glucosamine supplements, including their potential health benefits, safety, side effects, and more.

Benefits of Glucosamine

Glucosamine is a popular dietary supplement that’s often used as a natural remedy for conditions that affect the bones and joints, including osteoarthritis and temporomandibular joint disorders (TMJ), conditions that cause pain and dysfunction in the jaw joint and the muscles surrounding the jaw.

When taken as a dietary supplement, glucosamine may help reduce pain, joint swelling, and other symptoms in certain populations.

May Benefit People with Osteoarthritis

Knee osteoarthritis (OA), also known as degenerative joint disease, is a condition caused by the loss of cartilage in the knee. It’s most common in older adults, though it can occur in younger people, too. Knee OA is the most common form of arthritis, impacting up to 40% of adults over 70.

Though results are mixed, some studies have shown that glucosamine may improve cartilage structure, reduce pain, and improve physical function in people with knee OA.

A 2023 review of 15 studies found that glucosamine supplements were more effective than placebo treatments at reducing pain in people with knee osteoarthritis. The review also concluded that glucosamine sulfate supplements providing 1,500 milligrams of glucosamine per day were safe and well tolerated.

Certain forms of glucosamine may also help reduce markers of inflammation and positively affect cartilage structure by reducing cartilage degradation when taken in doses of 1,500 milligrams per day.

When combined with chondroitin, a major component of cartilage that can also be taken as a dietary supplement, glucosamine has been shown to improve symptoms in people with knee and hip OA, or osteoarthritis caused by cartilage deterioration in the hip joint.

A 2023 study that included 1,102 people with knee or hip OA found that treatment with capsules containing 500 milligrams of glucosamine hydrochloride and 400 milligrams of chondroitin sulfate three times a day for the first three weeks, then twice daily for a total of 64 weeks was associated with significant improvements in pain, OA symptoms, physical function, and quality of life. The study also found that the supplement led to a decrease in the need for non-steroidal anti-inflammatory drug use. However, keep in mind that this study did not have a control group.

Although some studies have found that glucosamine supplements may provide symptom relief and positively impact joint health in people with OA, study results are mixed, and experts and health organizations disagree on whether glucosamine supplements may help people with knee and hip osteoarthritis.

Some study findings also suggest that glucosamine supplements may help protect against cartilage breakdown in people without joint disorders, such as athletes. A 2018 study of 43 soccer players found that supplementation with 2 grams of glucosamine per day for 16 weeks suppressed collagen degradation compared to a placebo group.

May Protect Against Mortality

Although more research is needed, some evidence suggests that taking glucosamine supplements may protect against death from conditions like cancer and heart disease.

A large 2020 study that included data on over 495,000 people found regular glucosamine supplement use was associated with a 15% lower risk of death from all causes, an 18% reduced risk of heart disease-related death, a 6% reduced risk of cancer-related death, a 27% reduced risk of respiratory-related death, and a 26% reduced risk of death due to digestive conditions. Interestingly, the risk reduction was stronger amongst people who smoked.

Researchers think that glucosamine use may reduce inflammation, thus lowering mortality risk. While these results are encouraging, it’s currently unclear if glucosamine supplements offer protection against common causes of death.

May Reduce TMJ-Related Pain

Temporomandibular disorders (TMDs) are conditions that affect the jaw joints as well as the surrounding muscles and tissues. TMDs are the most common cause of non-dental-related mouth and face pain.

Temporomandibular joint osteoarthritis (TMJ OA) is a type of TMD that’s considered a degenerative joint disease (DJD). It’s a chronic degenerative disease that impacts the cartilage and the bone in the jaw and causes symptoms such as tenderness in the joint region and pain during mouth opening.

Glucosamine may be helpful for people with this condition as it may help reduce inflammation and protect against cartilage degradation.

A 2023 review of eight studies found that oral supplementation with glucosamine or glucosamine and chondroitin for three months led to a significant reduction in temporomandibular joint pain and a significant increase in maximum mouth opening in people with TMJ OA.

However, the researchers concluded that there is not enough scientific evidence to confirm the effectiveness of glucosamine supplements in the treatment of TMJ OA at this time.

How to Take Glucosamine

Glucosamine supplements are available in several forms, including tablets, pills, capsules, and powders. Glucosamine can also be applied topically by using glucosamine-containing creams and ointments.

The most common types of glucosamine found in supplements are glucosamine sulfate (GS) and glucosamine hydrochloride (GH).

These supplements are commonly taken in divided doses, twice or three times per day. It should be noted that glucosamine is slow to act, meaning that it might take a few weeks of supplementation before its effects are felt.

Keep in mind that patented crystalline glucosamine sulfate (pCGS) is a type of glucosamine that’s only available by prescription. pCGS is used to treat certain types of OA.

Dosage

Glucosamine dosing varies, but GS is commonly taken as a 500mg dose three times a day to treat OA, for a total dose of 1,500mg. It’s usually taken with meals to decrease the chance of gastrointestinal side effects.

The total dose of glucosamine depends on the form you’re taking. GS requires stabilizers, such as potassium chloride (KCl) or sodium chloride (NaCl). Because of this, GS has a 74% purity. GH has a 99% purity, meaning a dose of 1,500mg of GH is equivalent to a 2,608mg dose of GS.

If you’re not sure how much glucosamine you should be taking, contact your healthcare provider for dosing recommendations.

Is Glucosamine Safe?

When taken in appropriate doses, glucosamine is considered safe. However, glucosamine supplements aren’t appropriate for everyone.

Although it’s unclear if glucosamine supplements will cause adverse effects in these populations, people with shellfish allergy, asthma, and those on diabetes medications or warfarin should be monitored closely for safety when taking glucosamine and should not take glucosamine unless prescribed and monitored by a healthcare provider.

People with liver conditions should also be cautious with glucosamine as glucosamine is metabolized in the liver, and there have been reports of liver injury in people using glucosamine supplements.

Additionally, there’s not enough evidence to confirm the safe use of glucosamine in children and pregnant women.

Lastly, glucosamine supplements are often derived from shellfish, so they may not be safe for people with shellfish allergies.

Potential Drug Interactions

Glucosamine isn’t known to interact with many medications. However, it may reduce your body’s ability to clot blood, which could increase bleeding risk, especially if you’re taking an anticoagulant medication like Eliquis or blood thinning medications like warfarin.

Glucosamine supplements also have the potential to interfere with certain laboratory tests, including:

  • Blood glucose levels: Glucosamine may increase blood sugar levels, which may affect laboratory readings.

  • International Normalized Ratio (INR): Glucosamine has been shown to increase INR, a lab test used to assess blood clotting.

  • Alanine aminotransferase (ALT): Glucosamine supplements may increase the liver enzyme ALT, which is used to assess liver health.

What to Look For


Glucosamine can be taken on its own, but it’s commonly combined with chondroitin and other substances in supplements marketed to support bone and joint health.

If you’d like to take a glucosamine-only supplement, it’s important to read supplement labels to ensure you’re purchasing the right product.

When possible, it’s always best to purchase dietary supplements that are certified by organizations like UL, USP, and NSF International, which are organizations that set strict standards for supplement quality and safety.

You’ll also want to choose a supplement that you can easily tolerate. For example, people who can’t tolerate swallowing pills may want to purchase a powdered glucosamine product.

Can You Take Too Much Glucosamine?


When supplementing with glucosamine, it’s important to follow dosing recommendations. Although high doses of glucosamine of up to 3,000 milligrams per day have been safely used in research studies, it’s unclear if higher doses may have adverse health effects.

Keep in mind that higher doses may be more likely to cause gastrointestinal side effects such as gas.

Side Effects of Glucosamine

Glucosamine is considered a safe supplement and isn’t associated with serious side effects.

However, in some cases, glucosamine supplements may lead to:

If you experience any side effects after taking a glucosamine supplement, stop taking the supplement and contact your healthcare provider for advice.

Keep in mind that glucosamine supplements aren’t safe for everyone and may cause more serious side effects in people with certain health conditions, such as those with shellfish allergies.

A Quick Review

Glucosamine is a substance that’s naturally produced by your body that can also be taken as a dietary supplement.

Some evidence suggests that glucosamine supplements may help reduce pain and other symptoms in people with certain health conditions, including knee OA and TMJ OA.

Glucosamine is considered safe, but it’s not the right choice for everyone. If you’re interested in taking glucosamine, consider speaking with your healthcare provider. They can help you determine whether a glucosamine supplement may be the right choice for your health needs and can recommend a safe and effective treatment plan.

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Read the original article on Health.

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