The caffeine in Alpecin penetrates through the scalp and quickly reaches the hair follicle. There it contributes to extending the growth phases of the individual hair roots much longer than provided by hereditary predisposition. This is shown by the graphic:

Caffeine Shampoo – the shampoo that stimulates hair growth directly at the roots
Washing your hair daily with Alpecin Caffeine Shampoo immediately provides the hair roots with the activating caffeine ingredient, which can be detected after being left on for as little as 120 seconds. This shampoo does not contain any conditioning agents so your hair will immediately have more grip.

Caffeine Shampoo 250ml:
£ 4.99 recommended retail price

Liquid – strengthens hair roots, prevents hair loss
With its caffeine-based ingredient combination, Alpecin Liquid keeps the hair roots active and helps extend their growth phase longer than genetically predisposed. The active ingredients are applied directly where they are needed. This way, Alpecin allows a highly effective dosage without stressful impacts on the organism.

Liquid 200ml:
£ 6.99 recommended retail price