Keeps dark hair dark. Powerful color pigments in the shampoo keeps the dark hair color. This can make the hair look fuller and darker. If a man starts early enough, the first gray hairs become visible late. The color effect is inconspicuous, only becomes more intense with regular use and gradually washes out with normal shampoo.At the same time, the caffeine complex stimulates the hair root and prevents hereditary hair loss. Daily hair washing with the Tuning Shampoo immediately supplies the hair roots with the activating active ingredient. The Alpecin caffeine can be detected there after just 120 seconds of exposure.Leave on the scalp for 2-5 minutes - from application to rinsing. Use only on dark to black hair.