N-Acetyl Glucosamine and Niacinamide: N-Acetyl Glucosamine and Niacinamide block melanin production. A key enzyme in melanin biosynthesis is tyrosinase. It is initially produced in the cell as an inactive pro-enzyme, which is then glycosylated to the active form. While N-Acetyl Glucosamine (a sugar itself) is not a direct inhibitor of tyrosinase, it does inhibit the activation of the enzyme, resulting in a decrease in melanin. Niacinamide inhibits the transfer of melanin-containing melanosomes to the outer layers of skin, helping to prevent the formation of an age spot. Excessive melanin formation is dependent on UVR Exposure.