Retinol is a powerful ingredient that can be irritating on the skin if used incorrectly. Here are some things to avoid when using retinol:

• AHAs: Glycolic Acid Toner, Alpha Hydroxy Acid, Lactic Acid, Mandelic Acid Treatment, Apple Cider Vinegar Acid Peel, and other exfoliating AHAs should not be mixed with retinol as they can cause more irritation and dryness when paired with retinols.

• BHAs: Beta Hydroxy Acid Serum, C-50 Blemish Night Treatment, and other exfoliating BHAs should also be avoided when using retinol.

• Vitamin C: Vitamin C Serum should not be combined with retinol as it can cause skin irritation and redness. If you want to use both, apply them on alternate days.

• Benzoyl Peroxide: Benzoyl Peroxide should not be used with retinol as it can cause skin irritation and redness. If you want to use both, apply them on alternate days.

It is recommended to use retinol with moisturizers and hyaluronic acid, which can help to minimize the drying and irritating side effects of retinol. Additionally, it is important to start with a low concentration of retinol and gradually build up tolerance to avoid skin irritation and peeling.