A post-marketing surveillance study with Alpecin Double-Effect Shampoo compared to an anti-dandruff shampoo, which was previously considered the best*, had the following result: A significant decrease in dandruff was proven after just 21 days of daily application. The Alpecin Double-Effect Shampoo effected a stronger reduction in dandruff than the comparative product.
Alpecin Double-Effect Shampoo does not just remove dandruff but also protects the hair roots from the negative impacts of testosterone with the caffeine complex. In a short period of time (120 sec.), the caffeine complex penetrates the hair follicle along the hair shaft to create a 24-hour active ingredient depot. This was proven by a study conducted by the Berlin university clinic (Charité).
The graphic shows the penetration of caffeine after a processing time of just 120 seconds. As early as during the first few minutes, the caffeine from the shampoo has reached the hair roots where it remains detectable after up to 24 hours.
