Vitamin C Serum Guides
Evergreen, referenced explainers on using vitamin C serum well. For launches and product updates, see News.
How to Use Vitamin C Serum
Step-by-step guide to using vitamin C serum: when to apply it, how much, whether it goes before or after moisturiser and sunscreen, and how to avoid irritation.
Can You Use Vitamin C and Niacinamide Together?
Whether vitamin C and niacinamide can be used together, where the old warning came from, and practical ways to layer or alternate them.
Vitamin C and Retinol: How to Use Both
How to use vitamin C and retinol in the same routine without irritation: the simple AM/PM split, when to layer, and who should go slowly.
Vitamin C Serum with Sunscreen
Why vitamin C and sunscreen work well together, which goes first, how long to wait, and why vitamin C never replaces sun protection.
Why Vitamin C Serum Turns Yellow or Brown (Oxidation)
Why vitamin C serum changes colour, when an oxidised serum should be thrown away, and how to store vitamin C so it stays effective for longer.
Vitamin C Serum: Morning or Night?
When to apply vitamin C serum and how timing interacts with sunscreen and other actives.
Vitamin C Ingredient Encyclopedia
L-ascorbic acid and its derivatives compared: stability, strength and skin-type fit.