Vitamin C

What it does

An antioxidant that fades dark spots, evens tone and gives that lit-from-within look. It also supports your sunscreen's work during the day. Look for 10-15%; gentler derivatives (SAP/MAP) trade some punch for stability and less sting.

How to use it

Morning serum, before moisturizer and sunscreen. Keep the bottle away from light and air - oxidized (dark orange) vitamin C is spent.

What not to mix it with

• benzoyl peroxide - see Vitamin C + benzoyl peroxide
• AHAs (same session) - see Vitamin C + AHA
• BHAs (same session) - see Vitamin C + BHA
• copper peptides - see Copper peptides + vitamin C
• retinoids (same session) - see Retinoid + vitamin C

What it gets along with

Better with friends: ferulic acid and vitamin E make vitamin C more stable and more effective. And the old niacinamide clash is a myth in modern formulas - they layer fine.