L-Ascorbic Acid

Also known as: Vitamin C, Ascorbic Acid, LAA

Generally SafeantioxidantEWG: 1

The most potent and research-backed form of Vitamin C — a brightening antioxidant and collagen co-factor.

How it works

L-Ascorbic Acid neutralises free radicals, inhibits melanin synthesis by suppressing tyrosinase, and is an essential co-factor for collagen biosynthesis. It is the only form the skin can use directly without conversion. However, it is highly unstable and oxidises quickly — formulas must be at pH 2.5–3.5 and packaged to exclude air and light.

Concentration note

Effective range: 10–20%. Above 20% increases irritation without added benefit. Below 8% has limited efficacy.

Best for

HyperpigmentationDull skinUV damageCollagen supportBrightening

Avoid if

Highly sensitive skin (low pH causes tingling)

Commonly found in

Vitamin C serumsBrightening treatments

✅ Pairs well with

Vitamin E Ferulic Acid Hyaluronic Acid Niacinamide

⚠️ Avoid combining with

Retinol Glycolic Acid Salicylic Acid

Safety & restrictions

No significant safety concerns. May cause tingling at high concentrations or low pH. Ineffective or mildly irritating if oxidised (look for yellow/brown colour change).

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For informational purposes only. Not medical advice. Consult a dermatologist for personalised guidance.