Nioxin Pro Clinical's System Kit 4 is designed for dry, damaged, colored hair with progressed thinning. This is a lightweight conditioner that helps provide hair resilience, hydrates scalp and hair from root to tip. Clinically and dermatologically tested. Formulated with a powerful blend of niacinamide, biotin and caffeine to help nourish the hair root, stimulate hair follicles and strengthen the hair. Nioxin System 4 Conditioner enhances scalp health by promoting a healthy environment for hair growth. Its lightweight, moisturizing formula contains ingredients that strengthen the hair against damage and breakage, while promoting a healthier scalp. To use, apply a small amount of conditioner to wet hair after shampooing. Gently massage into the scalp and hair, focusing on areas of concern. Leave on for 1-3 minutes, then rinse thoroughly. For best results, use daily alongside the Nioxin System 4 Scalp + Hair Shampoo and Scalp + Hair Thickening Treatment. For optimal results, use the Nioxin System Kit 4 daily.