What Is an Antioxidant?
An antioxidant is a molecule capable of donating an electron to a free radical without itself becoming destabilised. In skincare, antioxidants are applied topically or consumed orally to neutralise reactive oxygen species (ROS) generated by UV radiation, pollution, and metabolic processes. Left unchecked, ROS oxidise lipids, proteins, and DNA — causing visible ageing and barrier breakdown.
How Antioxidants Work in Skin
When UV photons strike the skin, they generate singlet oxygen and superoxide radicals that cascade into collagen-degrading matrix metalloproteinases (MMPs). Topical antioxidants intercept this cascade at the point of ROS generation, reducing the downstream signalling that destroys collagen and elastin. This is why antioxidant serums are most effective in the morning, layered under sunscreen.
Key Topical Antioxidants
Vitamin C (L-ascorbic acid) is the most studied, with documented photoprotective and brightening benefits at 10–20%. Vitamin E (tocopherol) works synergistically with Vitamin C, regenerating its antioxidant capacity. Niacinamide, resveratrol, ferulic acid, and coenzyme Q10 are additional actives with established ROS-quenching evidence.
Synergy tip: Vitamin C + Vitamin E + ferulic acid is one of the most validated antioxidant combinations in dermatology, producing significantly greater photoprotection than any single ingredient alone.
See Antioxidants in Skincare and Free Radicals.