Vitamin C is one of the most popular and well-studied ingredients in skincare — a daytime antioxidant that helps brighten the skin, even out tone and defend against the daily damage of sun and pollution. But vitamin C serums can be fussy, so choosing and using the right one makes all the difference.
What vitamin C does for your skin
- Brightens and evens tone. It helps fade the look of dark spots and dullness, supporting a more radiant, even complexion.
- Protects against free radicals. As an antioxidant, it neutralises some of the damage caused by UV exposure and pollution — damage that contributes to premature ageing.
- Supports collagen. Vitamin C plays a role in the skin's natural collagen production, which helps keep skin firm and smooth.
Choosing a vitamin C serum
There are several forms of vitamin C. L-ascorbic acid is the most researched and most potent, usually used at concentrations between 10% and 20%. It is highly effective but can be unstable and slightly more irritating. Gentler derivatives (such as sodium ascorbyl phosphate or magnesium ascorbyl phosphate) are more stable and better suited to sensitive skin, though often milder in effect.
When shopping, look for:
- An opaque, air-tight bottle — vitamin C degrades in light and air.
- A sensible concentration (around 10–15% of L-ascorbic acid is a good starting point).
- Supporting antioxidants like vitamin E and ferulic acid, which help stabilise it and boost its effect.
How to use it
- When: Mornings are ideal, so its antioxidant protection works through the day. Always follow with sunscreen.
- Order: Apply after cleansing (and toner), before moisturiser.
- Start slow: If you have sensitive skin, begin a few times a week and build up to daily use.
- Storage: Keep it somewhere cool and dark. If your serum turns deep yellow or brown, it has oxidised and lost potency.
Vitamin C and sunscreen: a perfect pair
Vitamin C does not replace sunscreen, but the two work beautifully together. Sunscreen blocks UV rays, while vitamin C mops up some of the free-radical damage that still gets through. Using both in the morning gives your skin far better daytime defence than either alone.
The bottom line
A well-formulated vitamin C serum, used in the morning and followed by sunscreen, is one of the most rewarding additions to a routine — brighter, more even, better-protected skin over time. Choose a stable formula in good packaging, store it well, introduce it gradually, and be patient: visible brightening usually takes several weeks of consistent use.