Nioxin-Part System 2 Kit for thicker, fuller hair This professional 3-step system combines a shampoo, conditioner, and leave-in treatment specifically formulated for natural, untreated hair experiencing advanced thinning. The Scalp + Hair Thickening Treatment offers UV protection for both scalp and hair. It nourishes the scalp with key nutrients and antioxidants, helping to shield it from damage. Clinically and dermatologically tested, this regimen promotes noticeably thicker, fuller hair within 30 days. Key ingredients include niacinamide, wild mint oil, peppermint oil, and caffeine, all selected for their strengthening and revitalizing properties.