Caffeine neutralises the negative effect of testosterone

Conducted at the Clinic and Polyclinic for Dermatology and Venerology of the University of Hamburg-Eppendorf

New findings by the University Clinic in Hamburg and Dr. Kurt Wolff Research show that men‘s skin is more sensitive than that of women. This is due to the male hormone testosterone. It significantly weakens the skin‘s natural protective function and makes it more sensitive to irritation e.g. through hair washing, shaving and environmental impacts. Testosterone also has a negative effect on the skin's regenerative cells – the skin is slower in its recovery. If male skin or the male scalp is treated with a caffeine complex, the negative impact of testosterone can be eliminated. Thanks to caffeine, the skin is better protected and regenerates more quickly.

Testosterone attack on the scalp

With the help of a skin model, the impact of testosterone was researched at the University of Hamburg. Using different biological parameters, the condition of healthy skin that came in contact with testosterone (normal physiological concentration of 5 ng/ml) was assessed.

Microscopic image of the skin

Left: The intact skin barrier prevents penetration by Nile red.
Right: Nile red penetrates the skin layer weakened by testosterone.

The results:

  • Testosterone damages the skin's natural barrier: 
    Under the influence of testosterone, it is more difficult for the skin to retain its moisture. “Transepidermal water loss” increases significantly.
  • Testosterone makes the skin permeable:
    Using a special indicator (Nile red), the scientists measured whether substances can penetrate the skin. The photo shows: In unaffected skin, the red will remain on the outside. Skin weakened by testosterone allows Nile red to penetrate.
  • Testosterone weakens the skin‘s regenerative ability:
    The measurement of the keratinocytes‘ activity showed that cell division was significantly reduced due to testosterone.

Caffeine restores the skin's barrier

Caffeine was then applied to the testosterone-stressed skin model. Despite the hormonal attack, the “transepidermal water loss” was reduced to a normal level. The harmful impact of testosterone was practically fully compensated.

Caffeine strengthens the skin's regenerative ability

Cell division is significantly activated by the applied caffeine, as shown by the graphic.


Caffeine provides excellent protection against the harmful impacts of testosterone on the skin. If applied regularly, the skin barrier remains functional and the keratinocytes‘ cell regeneration is strengthened.


  • J. M. Brandner, M. J. Behne, B. Huesing,  I. Moll, Int. J. Cosmet. Sci. 2006, 28, 343–347.