Glucosamine — Frequently Asked Questions
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Frequently Asked Questions
Is glucosamine sulfate better than glucosamine hydrochloride?
Is glucosamine sulfate better than glucosamine hydrochloride?
Yes, clinical evidence favors glucosamine sulfate. The positive long-term trials (Reginster 2001, Pavelka 2002) all used pharmaceutical-grade glucosamine sulfate. The large GAIT trial that showed mixed results used glucosamine HCl. European guidelines specifically recommend the sulfate form based on this evidence.
Can I take glucosamine if I have a shellfish allergy?
Can I take glucosamine if I have a shellfish allergy?
Most glucosamine is derived from shellfish exoskeletons (chitin), but the allergenic proteins are in shellfish flesh, not the shells. Still, shellfish-allergic individuals may prefer vegetarian glucosamine made from corn fermentation, which is equally effective.
How long does glucosamine take to work?
How long does glucosamine take to work?
Most clinical trials show meaningful symptom improvement after 4-8 weeks of daily use at 1,500mg. Structural benefits (cartilage preservation) require longer use — the positive trials showing slowed joint space narrowing ran for 2-3 years.
References
- Herrero-Beaumont G, Ivorra JA, Del Carmen Trabado M, et al. (2007). Glucosamine sulfate in the treatment of knee osteoarthritis symptoms: a randomized, double-blind, placebo-controlled study using acetaminophen as a side comparator. Arthritis & Rheumatism. DOI PubMed
- Reginster JY, Deroisy R, Rovati LC, et al. (2001). Long-term effects of glucosamine sulphate on osteoarthritis progression: a randomised, placebo-controlled clinical trial. The Lancet. DOI PubMed
- Clegg DO, Reda DJ, Harris CL, et al. (2006). Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. New England Journal of Medicine. DOI PubMed
- Towheed TE, Maxwell L, Anastassiades TP, et al. (2005). Glucosamine therapy for treating osteoarthritis. Cochrane Database of Systematic Reviews. DOI PubMed
- Pavelka K, Gatterova J, Olejarova M, et al. (2002). Glucosamine sulfate use and delay of progression of knee osteoarthritis: a 3-year, randomized, placebo-controlled, double-blind study. Archives of Internal Medicine. DOI PubMed