Night serum more effective than pure 0.3% retinol *Retinoids can make the skin more sensitive to UVA radiation. Sun protection is especially important when using retinoids. This product should not be used in combination with other retinoids, including retinol and retinoic acid. This product is not an acne treatment. Acne-prone skin may experience worsening during the first few weeks of using any form of retinoid, including those used in this formulation.