- Glucosamine sulphate
- Glucosamine hydrochloride
For Patients & Caregivers
Conclusive evidence is lacking to support the effectiveness of glucosamine against arthritis.
Cartilage is composed of collagen, elastin, and a matrix of long sugar-protein molecules called proteoglycans and glycosaminoglycans (GAGs). GAGs are extremely important for the ability of cartilage to act as a shock absorber, because they are highly negatively charged and absorb water so that cartilage is gel-like and resilient. Osteoarthritis is characterized by a progressive degeneration of cartilage GAGs. Glucosamine facilitates the synthesis of GAGs, and therefore replenishing the availability of these molecules would slow the degeneration of cartilage. However, clinical trials yielded mixed results. Glucosamine can also protect cartilage from damage caused by NSAIDs, corticosteroids and by reducing inflammation.
- To reduce inflammation
Glucosamine may reduce inflammation by a mechanism that is different from the way typical non-steroidal anti-inflammatory drugs (NSAIDs - e.g., aspirin, ibuprofen) work. Although glucosamine helps improve symptoms in osteoarthritis, no scientific evidence supports the use of glucosamine frr any other inflammatory conditions.
- To prevent progression of and treat osteoarthritis
Several clinical trials on using glucosamine alone and in combination with chondroitin sulfate yielded mixed results.
- To treat temporomandibular joint disorder (TMJ)
Two clinical trials support the use of glucosamine in combination with chondroitin sulfate to treat TMJ.
- People with diabetes should consult with their doctor before beginning to use glucosamine, because it has been reported to affect blood insulin levels and glucose metabolism in the body when used intravenously. Although this effect has not yet been seen when glucosamine is taken by mouth, diabetics using glucosamine should check their blood sugar level more frequently.
- Adverse reactions are rare and glucosamine tends to be safe and well tolerated.
- Stomach upset
- Leg pain
- Edema (swelling)
- Allergic reactions
- Glucosamine-chondroitin combination may potentiate the effects of warfarin.
- Glucosamine use has been associated with increased INR returning to normal levels when glucosamine was discontinued.
- Concomitant use of glucosamine and warfarin resulted in increased INR.
- Use of glucosamine and celadrin may inhibit platelet aggregation.
- A study in rats suggests that oral consumption of potent glucosamine preparations may cause sclerotic side effects.
- Glucosamine has not been found effective in relieving back pain.
- Glucosamine may have a limited effect in older patients who have more severe arthritis or have had arthritis for longer periods of time.
- Glucosamine may take longer to act than NSAIDs, but once it does, its effects last longer after treatment is stopped.
For Healthcare Professionals
Glucosamine is an endogenous aminomonosaccharide synthesized from glucose. Found in mucopolysaccharides, mucoproteins and chitin (a cellulose-like biopolymer that is a major component of the exoskeleton of various marine invertebrates), it is used in the biosynthesis of proteoglycans and glycosaminoglycans. Glucosamine is often paired with chondroitin sulfate in the treatment of articular diseases.
Two small studies involving glucosamine and chondroitin showed improvement in reducing symptoms of temporo-mandibular joint (TMJ) disorder (2) and degenerative joint disease (DJD). A meta-analysis suggests that it is effective against osteoarthritis of the knee (1). However, data from other studies indicate no such benefits of glucosamine, chondroiting or the combination in preventing progression of knee or hip osteoarthritis (13) (18) (17) (19) (23). Data on efficacy of chondroitin alone are also conflicting (1) (16) (23).
No efficacy was seen with glucosamine in relieving back pain (3) (22), degenerative lumbar osteoarthritis (22), or in improving glucose metabolism in patients with type 2 diabetes mellitus (15). Studies have indicated that the effects of glucosamine may be limited in older patients who have more severe arthritis (4) or have had arthritis for longer periods of time (5).
A progressive degeneration of cartilage glycosaminoglycans is evident in osteoarthritis. Glucosamine is the first step in glycosaminoglycan biosynthesis and has been shown to increase proteoglycan amounts in vitro, by affecting the synthesis of monomeric proteoglycans capable of assembling into high molecular weight aggregates (7). Glucosamine can protect cartilage from metabolic impairment by NSAIDs, corticosteroids and by exerting anti-inflammatory effects (8).
- Reported adverse reactions include gastrointestinal complaints, headache, leg pain, edema, itching (8) and possible allergic reactions (2).
- Glucosamine-chondroitin combination may potentiate the effects of warfarin (20).
- Glucosamine use has been associated with increased INR returning to normal levels when glucosamine was discontinued (20).
- Concomitant use of glucosamine and warfarin resulted in increased INR (20).
- Use of glucosamine and celadrin may inhibit platelet aggregation through aspirin-like effects and by inhibiting the ADP receptor P2Y1 but not P2Y12 (21).
- A study in rats suggests that oral consumption of potent glucosamine preparations may cause sclerotic side effects (24).
A study in 10 people found that an infusion of glucosamine sulfate reduced glucose tolerance. This observation and recent in vitro evidence suggest that glucosamine can increase insulin resistance, resulting in the need for larger doses of insulin or oral hypoglycemic agents in diabetic patients (14).