Active ingredient

Vitamin C

INCIAscorbic Acid

2% to 10%Typical concentration

Last reviewed by BIOSAR Scientific Team, PharmD, Cosmetic Chemistry, Pharmacy practice on April 28, 2026.

What it is

Vitamin C, in skincare most often L-ascorbic acid, is a water-soluble antioxidant used to brighten tone, neutralise reactive oxygen species, and support collagen synthesis. It donates electrons to free radicals, regenerates oxidised vitamin E, and serves as a cofactor for prolyl hydroxylase in collagen formation. Effective at 5% to 20% (L-ascorbic acid) or 5% (stable derivatives like sodium ascorbyl phosphate). pH stability matters — store in opaque, sealed packaging.

Pregnancy and breastfeeding

Safe

Considered safe during pregnancy and breastfeeding.

Vitamin C is an endogenous nutrient and topical use is well-tolerated. Mother to Baby and Trivedi et al. (2017) flag no concern during pregnancy or lactation.

Mechanism in detail

What Vitamin C does

Antioxidant that helps neutralize free radicals and supports a more radiant complexion. Contributes to the appearance of even tone over time.

Evidence

What the research says

−34%Visibly smoother, firmer, less-lined skin in 6 monthsIn a 6-month double-blind trial, daily 5% vitamin C cream cut the photoaging global score from 6.7 to 4.4 versus placebo, a 34% improvement. Deep furrows softened and skin microrelief density rose, leaving firmer, smoother texture.Read the study →Exp Dermatol 2003 (Humbert)

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