Glucosamine is a natural component of healthy human cartilage. It can also be created synthetically and taken as a dietary supplement. Supplemental glucosamine is often taken in conjunction with chondroitin, which is another naturally-occurring component of human cartilage. These supplements are frequently used as a complimentary therapy to traditional treatments for osteoarthritis. There are two types of supplemental glucosamine: glucosamine sulfate and glucosamine hydrochloride. Although glucosamine sulfate is the more widely studied of the two, it is not definitively known which is the most effective. 

Most research studies that have investigated the use of glucosamine have used 500mg of glucosamine sulfate taken by mouth three times a day for 30 to 90 days. Alternatively, a single daily dose of 1.5 grams (1,500 milligrams) has also been employed in some studies. These doses are all recommended for individuals 18 years of age and older; glucosamine supplements are not recommended for use in children.

There are a number of safety concerns pertaining to glucosamine supplements that individuals should consider prior use. Potential allergic reactions are a possibility, due to the fact that glucosamine can be manufactured from the shells of shrimp, crabs, and other shellfish. Therefore, individuals with a shellfish allergy or iodine sensitivity should proceed with caution. For the majority of users, however, glucosamine has proven to be well-tolerated in studies lasting from 30 to 90 days in duration. Nevertheless, side effects may occur and include the following: upset stomach, drowsiness, insomnia, headache, skin reactions, increased sensitivity to the sun, and thickened fingernails. On rare occasions, abdominal pain, appetite loss, vomiting, flatulence, constipation, heartburn, or diarrhea may occur.

Individuals with diabetes should monitor their blood sugar levels carefully when taking a glucosamine supplement. Individuals with bleeding disorders (or those who take medications that increase the risk of bleeding) should also use caution, as glucosamine may increase the risk of bleeding. Glucosamine supplements should also be avoided by women who are pregnant or breastfeeding due to a lack of scientific evidence supporting their safety in such situations. Glucosamine supplements also have the potential to interact negatively with blood thinning medications (such as warfarin [Coumadin]), as well as non-steroidal anti-inflammatory medications (Tylenol, Aleve). It can also interfere with some anti-cancer therapies (chemotherapy) as well as certain drugs taken to control blood sugar in diabetes. Glucosamine supplements have no known interactions with other dietary supplements, herbs, or foods.

Glucosamine supplements have been studied for their use in treating a number of conditions affecting the bones and joints. There is initial evidence to suggest that glucosamine hydrochloride (consumed in a 2,000mg/day dose) may lead to improvement in knee pain among individual who have recurring knee pain due to of a pre-existing knee injury (Braham et al., 2003). A greater amount of research has focused on the use of glucosamine hydrochloride in the treatment of osteoarthritis. The evidence that has been most supportive of such a use focuses on one single combination supplement, known as CosaminDS, which contains glucosamine hydrochloride, chondroitin sulfate, and manganese ascorbate. Some studies have demonstrated that this product is effective at improving mild to moderate knee osteoarthritis (compared to those with severe osteoarthritis) (Leffler et al., 1999;  Das & Hammad, 2000).

Findings from one research study suggest that non-commercial preparations of glucosamine hydrochloride (used alone or in combination with chondroitin) may be useful in treating moderate to severe knee osteoarthritis; however, the findings of this particular study must be interpreted with caution due to the high response rate among those who received a placebo during the study (Clegg et al., 2006).

Glucosamine hydrochloride has also been studied for its use in the treatment of rheumatoid arthritis. One study showed that a specific glucosamine hydrochloride product was significantly more effective than placebo at reducing the pain associated with rheumatoid arthritis in 25 patients over a 12 week period; however, it was not shown to be effective in improving the number of painful and swollen joints, or certain inflammatory markers (such as C-reactive protein and erythrocyte sedimentation rate) (Nakamura et al., 2007).

Glucosamine and Fibromyalgia

The scientific research available regarding the use of glucosamine as a treatment for fibromyalgia related symptoms is limited to usage data from two surveys. In a telephone survey of 434 female fibromyalgia patients and 198 healthy control subjects, 23 women (5.3%) with fibromyalgia and 6 (3.0%) without fibromyalgia reported using glucosamine supplements. In fact, out of the10 most frequent herbs or dietary supplements consumed by those who participated in the survey, glucosamine was second only to omega fatty acids / fish oil / flaxseed oil (Shaver et al., 2009).

A study published in 2006 presented findings from the 2000-2001 National Population Health Survey, which is a population-based health survey conducted by Statistics Canada  every two years. Statistics Canada is the Canadian government agency responsible for providing statistics to help better understand a variety of aspects of Canadian life, culture, economy, society, population, and health. Over 11,400 individuals completed the survey. Several items on the survey assessed the respondents’ use of natural health products (NHP), which were defined as botanical and naturally-derived non-botanical products such as glucosamine and shark cartilage. All meal replacement supplement supplements, weight-gain formulations, and essential vitamin and mineral supplements were not assessed.

The survey found that glucosamine was the most widely used NHP, with 192 of every 1,000 persons reporting having used it in the two days prior to completing the survey. In addition, the survey also assessed the use of NHPs by individuals with pre-existing diseases. Of all the conditions reported, those with fibromyalgia were the most likely to report using NHPs (23.2%), followed by those with Chrohn’s disease / ulcerative colitis (17.4%). The study did not, however, report the number of individuals with fibromyalgia who reported using glucosamine supplements (Singh & Levine, 2006).

Another study of complementary and alternative medicine (CAM) usage among patients with rheumatoid arthritis, osteoarthritis, or fibromyalgia found that fibromyalgia patients were most likely of the three groups to use CAM. Of the 95 fibromyalgia patients included in this study, 20.7% reported using glucosamine (Herman et al., 2004).



1.        Braham R, Dawson B, Goodman C. The effect of glucosamine supplementation on people experiencing regular knee pain. Br J Sports Med. 2003;37:45-49.

2.        Leffler CT, Philippi AF, Leffler SG, et al. Glucosamine, chondroitin, and manganese ascorbate for degenerative joint disease of the knee or low back: a randomized, double-blind, placebo-controlled pilot study. Mil Med. 1999;164:85-91.

3.        Das A Jr, Hammad TA. Efficacy of a combination of FCHG49 glucosamine hydrochloride, TRH122 low molecular weight sodium chondroitin sulfate and manganese ascorbate in the management of knee osteoarthritis. Osteoarthritis Cartilage. 2000;8:343-350.

4.        Clegg DO, Reda DJ, Harris CL, et al. Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. N Engl J Med. 2006;354:795-808.

5.        Nakamura H, Masuko K, Yudoh K, et al. Effects of glucosamine administration on patients with rheumatoid arthritis. Rheumatol Int. 2007;27:213-218.

Herman CJ, Allen P, Hunt WC, Prasad A, Brady TJ. Use of complementary therapies among primary care clinic patients with arthritis. Prev Chronic Dis. 2004;1(4):A12.

Leave a Comment

{ 0 comments… add one now }

Google Analytics Alternative