Azelaic Acid Booster.

"Azelaic acid is fantastic because it actually helps prevent tyrosinase in your face from making your skin darker. Tyrosinase is the enzyme inside of your skin and body that allows your skin to produce the pigment, and the super cool thing about azelaic acid is that it stops that tyrosinase in the skin cells that are being overactive, those ones that are proliferating and making themselves really quickly that are causing that overactive darkness, but it doesn't target skin cells that are elsewhere on your body so you don't have to worry about azelaic acid changing your skin color. And not only does it help with the pigmentation, but azelaic acid can also fight the acne bacteria. It's really phenomenal. A lot of people don't see irritation with it and it really is a skincare superhero."