Caffeine shampoo The shampoo that stimulates hair growth directly at the roots. A daily hair wash with C1 immediately provides the hair roots with the activating ingredient. Alpecin Caffeine is very well detectable after being left on for as little as 120 seconds. If left on for longer, more caffeine will be absorbed into the scalp. - Hair energizer - With patented skin activator - C1 reduces hair loss - Stimulates hair roots during washing