Retinoids can make the skin more sensitive to UV radiation. Sun protection is particularly important when using retinoids. This product must not be used in conjunction with other retinoids including retinol or retinoic acid. This product is not a treatment for acne. Acne-prone skin may experience a temporary increase in acne during the first few weeks of using any form of retinoid including those used in this formulation.Apply a small amount to face in the PM as part of your skincare regimen, after water-based serums but before heavier treatments. Do not use with other retinoid treatments. Avoid unprotected solar exposure. If irritation occurs, cease use and consult a physician. Use only as directed on unbroken skin. Patch testing prior to use is advised.