How to Tell If Your Vitamin C Serum Has Oxidized: The Guide to Potency, Preservation, and Skin Safety
Vitamin C serum is considered a holy grail in the world of skincare routine. It combines to eliminate hyperpigmentation, boost collagen production and protect the skin from environmental damage. But this active ingredient has a major weakness—its instability. It can easily be destroyed by exposure to light, heat and oxygen, which is scientifically called oxidation. […]