How can glucosamine work in anti-arthritis treatments?
Glucosamine is thought to be used as a building block for the synthesis of hyaluronic acid and other glycosaminoglycans in the human body, thus supporting the healing and rebuilding of cartilage. In fact, these human polymers do contain N-acetylglucosamine as one of their monomeric building blocks, so that oral application of glucosamine as a precursor could potentially boost its synthesis. N-Acetylglucosamine which would be the more logical choice is not used due to its higher price, but this may change in future with the availability of biotechnologically produced N-acetylglucosamine. While the incorporation of added glucosamine into glycosaminoglycans has been shown in vitro (i.e. in laboratory experiments using isolated human cells), there is little (though some) clinical evidence for the efficacy of glucosamine in anti-arthritis treatments. In the US, glucosamine does not have FDA approval for medical use and, therefore, is classified as a dietary supplement while in Europe, it is approved as a medical drug and it is recommended as an effective and safe therapy for osteoarthritis. For the same reason, glucosamine is also used extensively as a feed supplement in veterinary medicine.