I heard you can’t mix certain acne ingredients, like benzoyl peroxide or salicylic acid, with other ingredients like retinol—is this true?

Yes, do not use benzoyl peroxide and salicylic acid at the SAME time as your tretinoin. Ideally, use 1 in the morning and tretinoin at night. Salicylic acid and benzoyl peroxide are strong medications that will kill the effect of the tretinoin.

Tretinoin can cause skin irritation. Some users may get dry, red, or peeling skin that requires them to use less medication, use it less frequently, or stop using it temporarily or altogether.