Plantur 39 Caffeine Shampoo for Fine, Brittle hair (250ml Bottle): Until menopause, a woman\'s hair roots are protected based on high levels of female hormones (oestrogen). After menopause, these hormone levels will decline and the impact of male hormones will increase. The consequence: The hair will grow thinner, fall out prematurely, and the scalp will become visible. The caffeine in these shampoos prevent the hormone-induced exhaustion of hair production. During hair washing, the active ingredient penetrates all the way into the hair follicle (detectable after 120 seconds).