Efficacies of different preparations of glucosamine for the treatment of osteoarthritis: a meta-analysis of randomised, double-blind, placebo-controlled trials

19 double-blind, placebo-controlled randomized controlled trials were included in this meta-analysis investigating the effect of glucosamine sulfate and glucosamine hydrochloride in the treatment of knee or hip osteoarthritis. Results indicated that neither preparation had a significant effect for pain reduction. Functional recovery appeared to be improved with glucosamine sulfate, specifically after 6 months of follow-up. Functional recovery was not examined in trials investigating the effect of glucosamine hydrochloride.