Glucosamine: Benefits, Dosage, Contraindications

Updated on 19 March 2025

Glucosamine is produced by the body from glucose and glutamine (an amino acid). It is a naturally occurring amino sugar in humans. It is used in the biosynthesis of macromolecules present in articular cartilage. Glucosamine is typically extracted from the shells of crustaceans such as crabs or shrimp. As a supplement, glucosamine is derived from marine exoskeletons or produced by synthesis and is available in salt form, including glucosamine sulfate, glucosamine chloride, glucosamine hydroiodide, and N-acetyl glucosamine. Glucosamine is necessary for the synthesis of glycoproteins, glycolipids, and glycosaminoglycans (also called mucopolysaccharides). These carbohydrate-containing compounds are found in tendons, ligaments, cartilage, synovial fluid, mucous membranes, eye structures, blood vessels, and heart valves. Glucosamine plays a crucial role in maintaining the integrity of cartilage in all joints.

Other name(s)

Chitosamine, D-Glucosamine, Glucosamine

Scientific name(s)

3-Amino-6-(Hydroxymethyl)Oxane-2, 4, 5-Triol Sulfate.

Family or group:

Carbohydrates

Active ingredients:

Sulfuric Acid

Indications

Rating methodology

EFSA approval.

Several clinical trials (> 2) randomized controlled with double blind, including a significant number of patients (>100) with consistently positive outcomes for the indication.

Several clinical trials (> 2) randomized controlled with double blind, and including a significant number of patients (>100) with positive outcomes for the indication.

One or more randomized studies or multiple cohorts or epidemiological studies with positive outcomes for the indication.

Clinical studies exist but are uncontrolled, with conclusions that may be positive or contradictory.

Lack of clinical studies to date that can demonstrate the indication.

Arthritis
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Clinical studies in adults with knee osteoarthritis show that taking oral glucosamine sulfate reduces pain by about 28% to 41% and improves functionality by about 21% to 46% compared to placebo over a period of up to 3 years. Other clinical research has shown that 1500 mg of glucosamine sulfate once daily for 6 months may be more effective at reducing pain than 1000 mg of paracetamol three times daily in patients with moderate knee osteoarthritis. A dose of 1500 mg of glucosamine sulfate has been used for up to 3 years, alone or in combination with 400 mg of chondroitin sulfate two or three times daily. Slightly higher (2000 mg per day) or lower doses (500 to 1000 mg per day) have also been used.

Posologie

Orally

500 - 2000 mg

3 - years

Adults, Seniors

dry extract

Synergies

Chondroitin

Skin Healing
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A clinical study in women aged 40 to 60 with skin hyperpigmentation and lentigines (primarily age- and sun-induced hyperpigmented spots) shows that the application of a cream containing 2% N-acetyl glucosamine and 4% niacinamide on the face twice a day with sunscreen for 10 weeks reduces facial hyperpigmentation compared to sunscreen alone.a0The effect of N-acetyl glucosamine alone is unclear.

Posologie

Cutaneously

Synergies

Nicotinamide

Reduction in the appearance of facial hyperpigmentation by topical N-acetyl glucosamine

Properties

Anti-inflammatory

Anti-inflammatory and chondroprotective activities have been observed in human osteoarthritic cartilage. Indeed, glucosamine is a primary substrate, stimulating biosynthesis and inhibiting the degradation of proteoglycans. It also stimulates synovial production of hyaluronic acid, a compound responsible for the lubricating and cushioning properties of synovial fluid. In vitro studies have shown that glucosamine sulfate exerts anti-inflammatory effects by altering the production of TNF-alpha, interleukins, and prostaglandin E2 in macrophages, as well as suppressing mast cell activation. According to other in vitro research, glucosamine restores proteoglycan synthesis and prevents the production of inflammatory mediators induced by cytokine IL-1-beta in rat articular chondrocytes.

Usages associés

Arthritis

Gastroprotective

Glycoproteins are important for protecting the intestinal lining against damage. The degradation of glycosaminoglycans is a significant consequence of membrane surface inflammation. Abnormalities in colonic glycoprotein synthesis have been implicated in the pathogenesis of ulcerative colitis and Crohn’s disease.

Antiviral

Glucosamine may have some activity against HIV. Preliminary evidence shows that it inhibits intracellular viral movement and blocks viral replication.

Bone density

Glucosamine is reported to induce osteoblastic cell differentiation and suppress osteoclastic cell differentiation, thus increasing bone matrix deposition and decreasing bone resorption to modulate bone metabolism in osteoarthritis.

Anticancer

In epidemiological research, the use of glucosamine and chondroitin has been associated with a reduced risk of lung cancer and colorectal cancer. The mechanisms of anticancer action remain unclear.a0

Dermatological effect

It has been shown that glucosamine accelerates wound healing, improves skin hydration, and decreases wrinkles due to its stimulation of hyaluronic acid synthesis. Furthermore, as an inhibitor of tyrosinase activation, it inhibits melanin production and is useful in the treatment of hyperpigmentation disorders.

Usages associés

Skin healing

Safety dosage

Adult: 500 mg - 2000 mg

Glucosamine sulfate has been used safely in several clinical trials for a duration of 4 weeks to 3 years. The typical dosage is 1500 mg of glucosamine.

Interactions

Médicaments

Antidiabetics: weak interaction

Glucosamine may increase insulin resistance or reduce its production.

Warfarin: strong interaction

Taking glucosamine alone or in combination with chondroitin may enhance the anticoagulant effects of warfarin (Coumadin) and increase the risk of bruising and bleeding.

Precautions

Pregnant women: avoid

Glucosamine sulfate use should be avoided during pregnancy due to the lack of reliable information.

Breastfeeding women: avoid

Glucosamine sulfate use should be avoided while breastfeeding due to the lack of reliable information.

Asthma: use with caution

Glucosamine may exacerbate asthma through an unidentified allergic mechanism. Use with caution in asthmatic patients.

Type 2 diabetes: use with caution

It is thought that glucosamine sulfate may increase insulin resistance or decrease insulin production, leading to increased blood sugar levels.

Glaucoma: use with caution

Taking glucosamine sulfate may increase intraocular pressure in patients with glaucoma.

Conseil scientifique