The Biological Advantage of N-Acetylglucosamine chart shows the process by which the human cell makes its own supply of N-Acetylglucosamine to produce hyaluronic acid (lower left) and chondroitin (lower right).

The chart is divided in three columns.

The central column depicts in graphic form the various molecules that are formed on the way to becoming N-Acetylglucosamine. The arrows between the molecules indicate whether the step from one molecule or the other is reversible. A single arrow indicates that the molecular change is not reversible. The left-hand column illustrates where along the pathway the commercially available glucosamine products enter the pathway. The right-hand column shows the size of the molecules in the pathway expressed as the
molecular weight.

What this pathway tells us:

The glucosamine sulphate or hydrochloride must first be converted to N-Acetylglucosamine before it can be made into hyaluronic acid or chondroitin. Note the double arrow between glucose and glucosamine.

Glucosamine can also be converted back to glucose and used for energy which makes it an inefficient treatment.