"Because Differin can be drying, I recommend mixing a pea-size amount of the product in with your favourite oil-free facial moisturiser (I recommend the Avene Tolerance Extreme Cream, £15), every night. Be patient with your acne, as acne is chronic and takes time to improve. If you're not improving after one to two months, I recommend that you see your board-certified dermatologist for evaluation and treatment." — Dr. Kitchin