Ascorbic Acid
Also known as: Vitamin C, L-Ascorbic Acid
What it is
The pure, biologically active form of Vitamin C. It is a potent antioxidant and a gold-standard ingredient for brightening, firming, and protecting the skin.
How it works
As a primary water-soluble antioxidant, it neutralizes free radicals. It is an essential cofactor for the enzymes prolyl and lysyl hydroxylase, which are required for collagen synthesis. It also inhibits the enzyme tyrosinase, reducing melanin production to brighten the skin.
Formulation notes
Effective concentration: 5% - 20%
pH range: < 3.5 for stability and penetration in aqueous solutions.
Stability: Highly unstable; degrades quickly when exposed to air, light, and water. Requires protective packaging.
Safety
Irritancy: Moderate, can cause tingling or irritation, especially at high concentrations.
Comedogenicity: 0
Warnings: May not be suitable for very sensitive or rosacea-prone skin.
Ratings
Paula's Choice: Best
INCIdecoder: superstar