N-Acetyl-Glucosamine

N-Acetyl-Glucosamine: What does it do?

N-acetyl-glucosamine (NAG) is a form of glucosamine, one of the building blocks of joint tissue and other connective tissues. NAG differs from glucosamine sulfate and glucosamine hydrochloride; instead of a sulfur or chloride molecule, NAG has a larger, more complex molecule attached to it. As a result, NAG is an entirely different molecule than either glucosamine sulfate or hydrochloride, and it also appears to be handled by the body differently.

Over the years, numerous researchers have repeatedly demonstrated in animal and test tube studies that NAG is inferior to other forms of glucosamine in terms of absorption and utilization.^{1 2 3 4 5 6 7} However, an animal study demonstrated that NAG was able to enhance the manufacture of cartilage in damaged joints.⁸ A recent human study compared the absorption of NAG to a long chain of NAG molecules (POLY-Nag).⁹ Results showed that orally ingested NAG and POLY-Nag are absorbed and increase the blood levels of NAG, with both forms yielding similar results. In addition, there was some conversion of both molecules to glucosamine. However, the degree of conversion still resulted in lower levels of blood glucosamine levels compared to glucosamine sulfate and glucosamine hydrochloride, which are both absorbed extremely well.^{10 11} Furthermore, unlike glucosamine sulfate, there have been no human clinical studies utilizing NAG to treat arthritis or other health problems.