Thank for this question. Applying BP just to the pimples will help dry existing pimples but will not prevent new pimples. As our target in the treatment of Acne is to prevent new pimples one must apply benzoyl peroxide products all over the face and not just to the single pimples. As BP may dry your skin you need to start with low percentage (usually 2.5%) and apply small quantities not more than once a day preferably at night. If after 2 weeks the skin is not too red or too you can increase the amount you apply gradually. It also important to keep moisturizing you skin during the treatment. Applying and oil free moisturizer or sunscreen in the morning will do the job.