Best Serum For Normal Skin: Isdin Melatonik 3-in-1 Night Serum The geniuses behind the Isdin Melatonik 3-in-1 Night Serum ($160) found a way to get melatonin into your nighttime skin routine after learning through clinicals that the ingredient can boost your inner antioxidant defences and fight off free radicals while you snooze. It will leave you with skin that looks brighter, healthier, and well-rested. Image Source: isdin.com Isdin Melatonik 3-in-1 Night Serum $160 from isdin.com Buy Now