Ingredients You Should Not Mix
Pairing two actives incorrectly can cancel them out — or burn your skin.
Retinol + exfoliating acids
Both accelerate shedding. Using them on the same night causes severe irritation and barrier damage. Alternate nights instead.
Vitamin C + benzoyl peroxide
Peroxide oxidises vitamin C and cancels its effect. Use vitamin C in the morning and peroxide at night.
Retinol + vitamin C
They work at different pH levels. Vitamin C in the morning, retinol at night.
What mixes safely
Niacinamide pairs with almost everything, and hyaluronic acid and ceramides are safe alongside any active.