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Vitamin C (L-Ascorbic Acid)

INCI: L-Ascorbic Acid
Also known as: LAA, Pure Vitamin C, Ascorbic Acid
Vitamin CantioxidantsyntheticStrong evidencePregnancy safe
96
Skinlumis Rating
Comedogenic
0/5
Irritancy
3/5
Best applied
AM
Effective range
10%–20%
How It Works

The most potent and best-studied form of topical Vitamin C. A pure, water-soluble antioxidant that neutralises free radicals, brightens, and is a co-factor for dermal collagen synthesis.

Donates electrons to neutralise ROS, inhibits tyrosinase to reduce melanin formation, and is a required co-factor for prolyl hydroxylase in collagen-I synthesis.

pH Range
2.5–3.5
Benefits
  • Brightens skin
  • Boosts collagen
  • Antioxidant protection
  • Fades dark spots
  • Doubles SPF photoprotection
Proven For

What the evidence supports.

HyperpigmentationPhotoagingDullnessSun damage
Best For
  • Normal
  • Dry
  • Combination
  • Mature
Avoid If
  • Highly sensitive skin (at high %)
Layering Order
3/10

Apply early in routine, toner/essence step.

Max Safe Concentration
20%

Concentration range in well-formulated products: 10%–20%

Seasonal Use

Year-round; especially powerful AM in summer paired with SPF.

Nutrition Connection

Dietary Vitamin C: citrus, kiwi, bell peppers, broccoli, strawberries.

Skin Signals When You Need It
  • Easy bruising
  • Slow wound healing
  • Dull, sallow tone
  • Bleeding gums
For Estheticians & Professionals

Decants and pumps preserve potency. Discard any formula that has turned amber.

Notable Research
  • Pinnell et al. 2001, 15% LAA + 1% Vit E doubled photoprotection vs SPF alone
  • Humbert et al. 2003, 5% LAA improved photoaged skin clinically
Clinical Evidence

The research behind Vitamin C (L-Ascorbic Acid).

4 peer-reviewed studies

Every claim on this page traces to published research. Findings below are drawn from randomized trials and systematic reviews, each links to the study on PubMed.

Randomized Controlled Trial
Vitamin C showed comparable efficacy to hydroquinone for melasma treatment.
Espinal-Perez LE, Moncada B, Castanedo-Cazares JP
International Journal of Dermatology, 2004
View Study →
Randomized Controlled Trial
Niacinamide inhibits melanosome transfer to keratinocytes, reducing hyperpigmentation by up to 35%.
Hakozaki T, Minwalla L, Zhuang J et al.
British Journal of Dermatology, 2002
View Study →
Randomized Controlled Trial
Azelaic acid comparable to hydroquinone for hyperpigmentation with superior safety across all Fitzpatrick types.
Balina LM, Graupe K
International Journal of Dermatology, 1991
View Study →
Randomized Controlled Trial
Daily sunscreen use reduced photoaging markers by 24% over 4.5 years compared to discretionary use.
Hughes MCB, Williams GM, Baker P, Green AC
Annals of Internal Medicine, 2013
View Study →
Pairs Well With
Vitamin E (Tocopherol)Ferulic AcidSPF (Mineral/Zinc Oxide)
Conflicts With
RetinolNiacinamide (very high concentrations)Benzoyl PeroxideCopper peptides
Your Skin Compatibility

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