Aza acid is azelaic acid, which is often heard. It has nothing to do with azaleas. Its main functions are acne, oil control and whitening. It can play the role of sterilization and anti-inflammation, so it is also very friendly to rose acne. At the same time, it can regulate excess oil and inhibit overactive melanocytes, so there are acne marks and spots, and it also has a good effect.