What Is Vitamin C? — The Antioxidant Workhorse
Vitamin C is the most-evidence-supported daytime antioxidant. The right form, concentration, and routine multiplies its effect.
The science.
Vitamin C is L-ascorbic acid. Topically, it acts as a free-radical scavenger, protects against UV damage, and supports collagen synthesis.
How it works
L-ascorbic acid donates electrons to neutralise UV-generated free radicals. It also inhibits melanin production and stimulates collagen synthesis.
Right for which skin types?
All skin types from age 25+. Particularly good for hyperpigmentation, sun damage, and oxidative-stress-related aging.
How to use it
10-20% L-ascorbic acid in the morning, before SPF. Apply to dry skin, wait 2 minutes before next product.
Side effects
Stinging on sensitive skin. Stop using if it turns brown (oxidised).
Top recommendations.
- C E Ferulic by SkinCeuticals — $220 · Clinical reference
- C15 Super Booster by Paula's Choice — $80 · Best value
- Vitamin C 23% by The Ordinary — $15 · Strongest budget
Common questions.
L-ascorbic vs THD ascorbate?
L-ascorbic is most-evidence-supported. THD is gentler but slower.
Can vitamin C oxidise?
Yes — discard if it turns brown. Store in dark, cool place.
How long until results?
Brightening: 4-6 weeks. Pigmentation: 12-16 weeks.