nicotinamide is best paired with other ingredients like hydroquinone, kojic acid, arbutin, and soy, which can work synergistically on the 'pigment pathway' to best help clear brown spots and discoloration," says Herrmann.
1.Hydroquinone: a medical-grade skin lightening agent (~4-8%) reduces tyrosinase activity, an enzyme involved in the production of new melanin (i.e., pigment). It is more effective than other brightening ingredients such as kojic acid, glycolic acid, and azelaic acid. 2.Retinoids: prescripti...