Vitamin C: The Complete Guide

Vitamin C is the gold-standard brightening antioxidant — and the one whose formulation matters most. This guide explains what it does, the difference between the forms you’ll see on labels, and how to use it for the best result.

What does vitamin C do for skin?

• Brightens and evens tone — helps fade the look of dark spots and dullness for a more radiant complexion.
• Antioxidant defence — neutralises free radicals from sun and pollution that accelerate visible ageing.
• Supports collagen — vitamin C is a cofactor the skin uses in making collagen, supporting the look of firmness.

The forms of vitamin C (why it matters)

Pure vitamin C (L-ascorbic acid) is powerful but unstable — it oxidises quickly, turning brown and losing potency. Newer stabilised derivatives such as 3-O-ethyl ascorbic acid resist oxidation, stay effective for longer, and tend to be gentler. Our Vitamin C Serum uses an ether-stabilised vitamin C that converts to active vitamin C in the skin, so you get the brightening benefit without the instability.

How to use vitamin C

Vitamin C is a morning hero: apply after cleansing, before moisturiser, then always follow with SPF — the two work together, and vitamin C helps boost your sun protection’s antioxidant defence. Store it away from heat and light, and if a pure-C formula turns deep orange or brown, it has oxidised and should be replaced.

Can you use vitamin C with other actives?

Yes. Vitamin C pairs well with niacinamide and hyaluronic acid. Many people use vitamin C in the morning and retinol at night to keep both comfortable, though that’s a preference rather than a strict rule. It layers cleanly under a copper-peptide cream.

See how it fits the wider range in the Ingredient Glossary, or find your match with the skin quiz.

Frequently asked questions

When should I apply vitamin C, morning or night?

Morning is ideal, because its antioxidant defence complements your SPF against daytime sun and pollution. It can be used at night too.

Can I use vitamin C with retinol?

Yes, though many people separate them — vitamin C in the morning, retinol at night — to keep sensitive skin comfortable.

Which form of vitamin C is best?

Pure L-ascorbic acid is the most studied but least stable. Stabilised derivatives like 3-O-ethyl ascorbic acid stay effective longer and are gentler, which is why we use one.

Does vitamin C help with dark spots?

Yes — it’s one of the most reliable ingredients for visibly brightening and evening the look of tone with consistent use and daily SPF.

Why has my vitamin C turned orange?

That’s oxidation — the vitamin C has degraded and lost potency. Replace it, and choose a stabilised formula to avoid it.