Cosmetic components generally contain unsaturated components. The oil phase needs antioxidants to prevent oxidation of unsaturated components, which causes rancidity; active components and preservatives containing unsaturated structures need antioxidants to prevent deterioration and discoloration. Oxidation in the air (autoxidation) may destroy the flavor, as oxygen reacts with different components of the flavor to produce unpleasant odors.
The effect of antioxidants can generally be enhanced by the addition of ascorbyl palmitate and chelating agents, which must be distributed in the aqueous and oil phases. Oil-soluble components require oil-soluble antioxidants, and water-soluble components require water-soluble antioxidants. Commonly used antioxidants include: BHA, BHT (butylhydroxytoluene), TBHQ (tert-butylhydroquinone), tocopherol, etc.
Oxidative stress breaks down collagen. Decreased collagen levels in the skin can lead to sagging, fine lines and wrinkles. Antioxidants fight all these signs of aging and give the skin a youthful glow.
Oxidative stress can trigger skin inflammation and lead to acne. Antioxidants reduce oxidative stress, thereby reducing inflammation and acne.
The skin responds to harmful UV-B rays from the sun by triggering an inflammatory response. Because antioxidants are effective anti-inflammatory compounds, they can prevent inflammation or sunburn.
Melanin (skin pigmentation) is produced by prolonged exposure to sunlight and free radical damage. Antioxidants fight both causes, so melanin production is reduced. The result is brighter skin.
Antioxidants are an important ingredient in any product that contains oils or other ingredients that are susceptible to oxidation. The use of antioxidants in balms, salves, lotions and creams can increase the stability of the oil in the product, thereby extending the shelf life of the product.