So, what gives? Does it depend on the percentage of vitamin C included in the serum? And — why apples? According to Ron Robinson, cosmetic chemist and founder of BeautyStat, apples are particularly ...

We tested the best vitamin deficiency tests from LetsGetChecked, Everlywell, and LabCorp, and our testers found them easy to use and informative. Learn more about the best vitamin deficiency tests ...

Vitamin C is one of the most versatile and transformative products you can have in your beauty arsenal. This powerful antioxidant can decrease the appearance of dark spots, brighten and even skin tone ...

Topical vitamin C and retinol both provide anti-aging benefits to your skin, and combining them may compound their effects, but may cause irritation.