Should I apply my acne spot treatment over or under my moisturizer?
The rule of thumb is "thin to thick." This means that you should put on your thinnest product first, and layer the thickest one last. Typically, acne spot treatments are going to be a little thinner than moisturizers, but this varies with certain products. I recommend the La Roche-Posay Effaclar AI Intensive Acne Spot Treatment ($29.90; lovelyskin.com).
Joel Schlessinger, MD, is president of LovelySkin.com and past president of the American Society of Cosmetic Dermatolgy and Aesthetic Surgery.