Where it gets murky is the same place glutathione gets murky: "Varnya" in the classical texts is about radiance, clarity, and evenness of complexion, not a specific target shade, and a lot of modern marketing has stretched that older idea into "skin whitening" language the same way it's happened to glutathione
They are not FDA-approved for general human therapeutic application
Controlling NAD + -biosynthesis pathway Enhancing NAD + -biosynthesis is one alternative approach to elevate NAD + concentration through either increasing the activity of enzymes in NAD + -biosynthetic pathway or inhibiting the activity of enzymes in the side branch pathway
BIOTIN C TC DNG G
A., Wang, H., Maller, G., DeSouza, R., & Khan, I