Ingredients
What does vitamin C do for skin?
Vitamin C is a powerful antioxidant that protects skin from free radicals created by sun and pollution. It is one of the most popular serums for dull skin and dark spots.
At a glance
- Best for
- Dull skin, sun spots and uneven tone, preventing signs of ageing
- Typical strength
- L-ascorbic acid 10–20%; gentler derivatives for sensitive skin (SAP, MAP, ascorbyl glucoside)
- When
- Morning, after cleansing; followed by moisturiser and sunscreen
- Pairs well with
- Sunscreen, vitamin E and ferulic acid, niacinamide, hyaluronic acid
- Caution
- Strong acids and retinol at the same time; serum that has turned orange-brown (oxidised)
What is vitamin C?
The most researched form of vitamin C for skin is L-ascorbic acid. It is effective but unstable and oxidises easily with light, air and heat, which is why it is sold in dark, airtight packaging. Derivatives such as sodium ascorbyl phosphate, magnesium ascorbyl phosphate and ascorbyl glucoside are more stable and less irritating but usually act more slowly.
Benefits for skin
Vitamin C neutralises free radicals created by sunlight and pollution; it does not replace sunscreen but supports it. By suppressing melanin production it helps fade dark spots and makes skin look more even and radiant.
It is also involved in collagen production, so regular use supports firmness.
How to use it
In the morning after cleansing, apply a few drops to face and neck, let it absorb, then apply moisturiser and sunscreen. If you are new to it, start with a strength of around 10%.
Store the serum in a cool, dark place with the cap tightly closed. If it has turned clearly orange or brown, it has oxidised and is less effective; stop using it.
Things to watch out for
Low-pH L-ascorbic acid serums can sting and redden sensitive skin; in that case switch to a gentler product with a derivative. Rather than using strong AHA/BHA acids and retinol at the same time, keep those for the evening. Vitamin C is considered one of the actives that can be used during pregnancy.
Frequently asked questions
Should you use vitamin C in the morning or at night?
The morning is usually recommended because its antioxidant effect adds protection against sun and pollution during the day. Evening use is possible, but morning makes more sense.
Can you use vitamin C with niacinamide?
Yes. The idea that they cancel each other out does not apply to modern formulas.
How long does vitamin C take to fade dark spots?
With regular use, radiance improves within a few weeks, while dark spots usually fade noticeably after 8–12 weeks. Without daily sunscreen the effect is much weaker.
This page is general information, not medical advice. If you have a skin condition, are pregnant or take regular medication, talk to a dermatologist before starting a new active ingredient.
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