You don't have to be a supplement expert to have heard of glucosamine. It's one of the most popular non-vitamin dietary supplements used by adults, and unlike many other supplements, it's popular both among heavy-lifting bodybuilders and aging populations.[1]

Why? Because both of those groups have a tendency to have sore joints! If that describes you, and you're thinking of taking glucosamine, here's what you need to know.

What Is Glucosamine?

Glucosamine is an amino sugar that is a component of the cartilage in your body. As a supplement, it is most commonly taken in the form of glucosamine sulfate, often in combination with chondroitin. It is the most commonly used supplement for joint health.[1] It is often made of chitin, a substance in the shells of shellfish like shrimp and lobsters, but can also be derived from certain plants like corn and wheat.

What Does It Do?

It's not exactly clear how glucosamine and chondroitin-based supplements work. However, glucosamine is a principal component in certain components of connective tissues, including joint cartilage.[5] The usage of glucosamine-containing supplements for joint health, and decreasing joint pain, has been a topic of research for greater than four decades.

What Are the Benefits?

Long-term, randomized control studies have shown that glucosamine supplementation can help delay the progression of joint arthritis, and pain associated with osteoarthritis.[3,4] Additionally, in trials ranging from twelve weeks to three years, subjects experiencing joint pain saw it decrease through regular consumption of glucosamine supplements.[1,7]

Are There Negative Effects of Glucosamine?

Glucosamine is widely regarded as safe, and has been studied in doses of 1500 milligrams per day for up to three years.[4] Research studies in which glucosamine supplements were taken for greater than twelve months indicate glucosamine sulfate continues to have positive effects on joint health and pain while glucosamine/chondroitin, and other combination therapies were not as effective.[7]

A majority of glucosamine supplements are derived from seafood sources, which may be worth considering if you have seafood allergies.[1] If this is a concern for you, consider buying a glucosamine supplement that is specifically labeled as vegetarian.

In the past, there has been some concern that glucosamine could negatively affect insulin resistance, but several studies concluded that was not the case.[1,8,9]

Are There Any Drug Interactions?

Glucosamine is generally thought to be safe, but may interact with certain blood thinners or anti-cancer medications. Be sure to tell your doctor about all the supplements you take, so they can help you determine any potential risk.

Are There Any Dietary Forms of Glucosamine?

The raw materials used to make glucosamine supplements are found in nature and are often derived from chitin in shellfish including shrimp, crab, and lobster.[5] However, very few people consume shellfish shells, so it's not feasible for most of us to get glucosamine through the diet.

What Are the Different Forms of Glucosamine Supplements?

Glucosamine sulfate is by far the most popular variety. Glucosamine hydrochloride is less common, and lacks the same level of supportive evidence.[1] Glucosamine is also often combined with chondroitin, and this combination has been found to be similarly safe to glucosamine sulfate alone.[1]

How Is Glucosamine Taken?

Glucosamine supplements in powder or capsule form are usually taken daily at a dosage of 1500-2000 milligrams, which can be distributed into multiple doses throughout the day. It is also often sold in small ready-to-drink bottles.

According to safety research, glucosamine is safe to 2000 milligrams per day while chondroitin is regarded as safe to 1200 milligrams per day.[5] When selecting and purchasing glucosamine supplement products, it is important to choose one that is from a reputable brand. One research study from 2000 aimed to determine the active ingredient content in supplements that sold for less than one dollar per 1200 milligram serving, and they found that the products were inconsistent in their content of glucosamine active ingredient.[6]

Conclusion

Glucosamine supplements have been utilized safely for decades. The results suggest there are general positive impacts on joint health and pain across a range of individuals of various age, health, and training status.

Still, it is important to consider the quality and the cost of the supplement you are planning to purchase, rather than simply letting price determine your choice. Likewise, be sure to talk with your doctor about any potential interactions with medications.

References

1. Mehta, K., Gala, J., Bhasale, S., & Naik, S. (2008). Comparison Of Glucosamine Sulfate And A Polyherbal Supplement For The Relief Of Osteoarthritis Of The Knee: A Randomized Controlled Trial. Alternative Medicine Review, 13(1), 80-81.
2. Qato, D. M., Alexander, G. C., Conti, R. M., Johnson, M., Schumm, P., & Lindau, S. T. (2008). Use Of Prescription And Over-The-Counter Medications And Dietary Supplements Among Older Adults In The United States. Jama, 300(24), 2867-2878.
3. Pavelká, K., Gatterová, J., Olejarová, M., Machacek, S., Giacovelli, G., & Rovati, L. C. (2002). Glucosamine Sulfate Use And Delay Of Progression Of Knee Osteoarthritis: A 3-Year, Randomized, Placebo-Controlled, Double-Blind Study. Archives Of Internal Medicine, 162(18), 2113-2123.
4. Reginster, J. Y., Deroisy, R., Rovati, L. C., Lee, R. L., Lejeune, E., Bruyere, O., ... & Gossett, C. (2001). Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomised, placebo-controlled clinical trial. The Lancet, 357(9252), 251-256.
5. Hathcock, J. N., & Shao, A. (2007). Risk Assessment For Glucosamine And Chondroitin Sulfate. Regulatory Toxicology and Pharmacology, 47(1), 78-83.
6. Adebowale, A. O., Cox, D. S., Liang, Z., & Eddington, N. D. (2000). Analysis Of Glucosamine And Chondroitin Sulfate Content In Marketed Products And The Caco-2 Permeability Of Chondroitin Sulfate Raw Materials. Journal of the American Nutraceutical Association, 3(1), 37-44.
7. Black, C., Clar, C., Henderson, R., MacEachern, C., McNamee, P., Quayyum, Z., ... & Thomas, S. (2009). The Clinical Effectiveness Of Glucosamine And Chondroitin Supplements In Slowing Or Arresting Progression Of Osteoarthritis Of The Knee: A Systematic Review And Economic Evaluation.
8. Muniyappa, R., Karne, R. J., Hall, G., Crandon, S. K., Bronstein, J. A., Ver, M. R., ... & Quon, M. J. (2006). Oral Glucosamine For 6 Weeks At Standard Doses Does Not Cause Or Worsen Insulin Resistance Or Endothelial Dysfunction In Lean Or Obese Subjects. Diabetes, 55(11), 3142-3150.
9. Biggee, B. A., Blinn, C. M., Nuite, M., Silbert, J. E., & McAlindon, T. E. (2007). Effects Of Oral Glucosamine Sulphate On Serum Glucose And Insulin During An Oral Glucose Tolerance Test Of Subjects With Osteoarthritis. Annals Of The Rheumatic Diseases, 66(2), 260-262.