Nioxin System 6 Leave-In Scalp and Hair Treatment is formulated for noticeably thinning, medium to coarse, natural or chemically treated hair. This hair treatment includes SPF 15 sunscreen to help protect the scalp and contains antioxidants and botanicals to help clean away environmental residues, helping achieve moisture balance. How to use: Apply directly to entire scalp. Gently massage into scalp. Do not rinse. Use daily. May cause temporary redness to scalp after application.