Perricone Md Acne Relief Prebiotic Acne Therapy 30-Day Set is a simple, comprehensive system that works with your surface skin's natural microbiome to safely, gently and effectively treat and prevent the most troublesome acne, while restoring and maintaining a healthy skin balance, for clearer, blemish-free skin. This powerful regimen is clinically proven to be non-irritating and will not strip or over-dry skin.