"I was first introduced to this line in my dermatologist's office. I use it in conjunction with monthly dermabrasions. I have acne, which leaves post-inflamatory hyperpigmentation. However, in using this serum day and night I notice the dark marks fade a little faster after a breakout. During periods of clarity, it really softens and brightens my skin. My only complaint is that it does make the skin tingle for a few minutes after application, which can be a little annoying."