System Professional’s Purify Lotion is a targeted, leave-in treatment to protect against the appearance of dandruff. Offering 24-hour protection, the pH-neutral formula helps to soothe from scalp to lengths. It works to remove the micro-organisms that may cause dandruff, supporting a fresh, flake-free finish. Designed for use after shampooing, the hair treatment also seeks to calm irritation. Its purifying benefits unite to promote a soft, clean-looking mane. Dermatologist-developed and tested.