Blog / Vitamin C
Vitamin C Serum
Vitamin C serum is one of the most studied brightening ingredients in skincare. As an antioxidant it helps defend skin against environmental damage, supports collagen, and fades the look of dark spots. Used correctly — morning, before moisturiser and sunscreen — it is a strong addition to a clear routine.
What is vitamin C serum?
Vitamin C serum is a concentrated liquid with ascorbic acid or a vitamin C derivative, applied after cleansing and before moisturiser. It is an antioxidant: it neutralises free radicals from sun and pollution, supports collagen production, and slows melanin production, which is how it fades the look of dark spots and brightens dull skin. It does not replace sunscreen — it works alongside it.
What vitamin C serum does
- Brightens dull skin. By slowing excess melanin production and adding antioxidant protection, skin looks more even over weeks.
- Fades the look of dark spots. Post-acne marks and sun spots gradually look lighter with steady use.
- Supports collagen. Vitamin C is involved in collagen synthesis, which keeps skin firm.
- Defends against environmental damage. Antioxidants neutralise some of the free-radical damage from sun and pollution — protection that sunscreen alone does not cover.
How to use vitamin C serum
- Morning. After cleansing, on slightly damp skin.
- Two or three drops. Pat over the face, avoiding the eye area. Wait about a minute.
- Moisturiser, then SPF. Moisturiser locks it in; sunscreen finishes the morning routine.
Night use is possible, but morning pairs its antioxidant protection with sunscreen — the combination most people get the most from.
Starting strength
Start at 5–10% for beginners and sensitive skin. Move to 15–20% once skin is used to it. Higher is not automatically better — irritation undoes the benefit. L-ascorbic acid is the most studied form; derivatives such as sodium ascorbyl phosphate are gentler and less likely to irritate, at the cost of slower results.
Layering
- Vitamin C first, then hyaluronic acid. Both are water-based; the antioxidant goes first.
- Niacinamide after a short wait. Apply vitamin C, wait about a minute, then niacinamide. Modern formulas combine them without issue for most skin.
- Do not stack strong exfoliants. When starting, avoid AHA/BHA exfoliants or retinoids in the same routine. Alternate days instead.
Oxidation: why serum turns brown
Vitamin C breaks down with light, heat, and air. A serum that turns dark orange or brown has degraded — replace it. A pale yellow to light amber colour is normal for many formulas. Store it cool and dark, close the cap promptly, and use it within the period on the label. Dropper bottles and dark glass help, but an old, brown serum is a serum to replace.
Who should be careful
Sensitive skin should try vitamin C on a small area first at a low strength. Persistent stinging, redness, or breakouts mean stop. Do not apply on broken or freshly exfoliated skin. If dark spots are changing shape, growing, or bleeding, see a dermatologist — no serum treats that.
Vitamin C and Lookauramax
One strong ingredient, used daily, beats five ingredients used occasionally. AuraScan measures skin as one of 7 Aura Signals, your Aura Routine keeps the morning steps steady, and your Aura Check-in at Day 30, 60, and 90 shows whether brightness is actually improving.
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See plans & free trial →Frequently asked questions
What does vitamin C serum do?
It brightens dull skin, fades the look of dark spots, supports collagen, and defends against environmental damage as an antioxidant. It does not replace sunscreen.
When should I apply vitamin C serum?
In the morning, after cleansing and before moisturiser and sunscreen. That pairs its antioxidant protection with SPF.
Can I use vitamin C with niacinamide?
Yes. Apply vitamin C first, wait about a minute, then niacinamide. When starting, introduce one product at a time.
Why did my vitamin C serum turn brown?
Vitamin C oxidises with light, heat, and air. A dark orange or brown serum has degraded and should be replaced. Store it cool, dark, and capped.
Can sensitive skin use vitamin C?
Often yes at a low strength (5–10%), tried on a small area first. If stinging or redness persists, stop and keep the routine gentle.
Disclaimer: This post is general information, not medical advice. Lookauramax does not diagnose or treat skin conditions. If you have a persistent skin condition, speak to a dermatologist.