Maximize Your Beauty Sleep With These 19 Overnight Hacks

Unfortunately, dark-spot-fighting ingredient vitamin C can't be used in the morning. According to Dr. Dennis Gross, sunlight can break down the powerful molecule. To get the most out of this ingredient, apply a treatment like Dr. Dennis Gross Skincare Hydra-Pure Vitamin C Brightening Serum ($95) before bed. The unique primer-like consistency of this formula makes it comfortable to layer with other evening beauty products.