Topical Vitamin C (L-Ascorbic Acid)
Morning antioxidant defence and gradual brightening. Pair with SPF — vitamin C amplifies sunscreen's protection against UV damage.
Strong for photoprotection (additive with SPF), hyperpigmentation reduction, and collagen synthesis over time. Effects: 6–12 weeks for visible brightening.
Topical L-ascorbic acid neutralises free radicals in skin from UV and pollution exposure, supports collagen synthesis, and inhibits melanin production (reducing hyperpigmentation). The Pinnell-formulation work at SkinCeuticals (15–20% L-ascorbic acid + ferulic acid + vitamin E at pH ~3.5) established the gold standard. The catch: L-ascorbic acid is unstable, oxidises in light and air (turns orange/brown — discard), and isn't tolerated by all skin types. Stable C derivatives (sodium ascorbyl phosphate, magnesium ascorbyl phosphate, ethyl ascorbic acid) work too but with less data.
- Form
- 15–20% L-ascorbic acid + ferulic acid + vitamin E at pH 3.5 (SkinCeuticals CE Ferulic, Timeless 20% C+E+F). Stable C derivatives if pure ascorbic acid is too irritating. Dark glass bottle, replace once it browns.
- Dose
- 3–5 drops over face, AM, before moisturiser and SPF.
- Timing
- AM. Synergistic with SPF — extends sunscreen protection.
- Schedule
- Daily.
- Side effects
- Stinging, redness, dryness, occasional breakouts in sensitive skin. Yellow stain on fabric.
- Interactions
- Benzoyl peroxide oxidises vitamin C — separate timing. Niacinamide (early concern about flushing reaction — debunked; fine to combine).
- Contraindications
- Active eczema / rosacea (use gentler stable derivative). Sensitive skin.
- Lab markers
- Visual / photographic skin tracking.
- Food sources
- Not food.
Pairs with
Sunscreen (synergistic UV defence). Ferulic acid + vitamin E (stabilise and amplify). Niacinamide (despite old myth, fine to combine).
within Topicals (skin / transdermal)