Alpecin Double-Effect Caffeine Shampoo in comparison to the leading market reference product against dandruff

Conducted by Derma Consult GmbH, organisation specialised in dermatological testing.

Product: Alpecin Double-Effect Caffeine Shampoo for dandruff and hereditary hair loss

Test subjects: 20 men aged 18 to 55 who suffer from pronounced dandruff.

Time period: The test subjects used Alpecin Double-Effect Caffeine Shampoo over the course of 6 weeks.

Problem and study objective

Dandruff as well as the genetic predisposition for hair loss frequently coincide in men. Due to the impact of the male hormone testosterone, the sebaceous glands are stimulated, which enhances microbiological growth and the associated formation of dandruff on the scalp.

Testosterone can also negatively impact hair growth in hereditarily predisposed hair roots and accelerate hair loss. This study tested the anti-dandruff effect of a caffeine shampoo, which contains a caffeine complex as well as an active ingredient combination against dandruff.

Fig. 1 Scalp at the start of the study
Fig. 2 Scalp after 21 days
Fig. 3 Scalp after 42 days

Study design

The test was conducted with 20 men aged 18 to 55, who suffered from increased dandruff. Prior to the test, the test subjects were prepared for the study with a neutral shampoo. The test shampoos used were the caffeine-containing anti-dandruff shampoo (Alpecin Double-Effect Caffeine Shampoo) and a comparative market reference product to which an excellent anti-dandruff effect had been attributed. The shampoos were used over a time period of 6 weeks. During this time, the microbiological activity on the scalp as well as the overall amount of dandruff were measured.

The condition of the scalp and the formation of dandruff directly on the scalp were recorded with special camera technology, and the images were quantitatively categorised upon conclusion of the tests. In a questionnaire, the test subjects also had the opportunity to provide their subjective assessments of the test products.

Graphic 1: Microbiological activity [%]


During the quantitative evaluation of the amount of dandruff, it became apparent that the overall measurable amount of dandruff decreased very well in comparison to the market reference product. [Graphic 2] The antimicrobiological effect against Malassezia furfur (microorganisms) was also excellent for both products. The number of germs is approximately reduced by half. [Graphic 1] The comparison of the scalp images confirmed the results very effectively. [Figures 1 to 3]

Graphic 2: Quantitative dandruff reduction [%]


The subjective assessment of the anti-dandruff effect confirms the quantitative results. From the users’ point of view, the formation of dandruff decreased significantly. Compared to the market reference product, the test shampoo was equally effective. However, the comparative study also showed that dandruff formation on the scalp is subject to strong individual fluctuations and that neither the test shampoo nor the market reference product eliminated dandruff completely in all cases during the period of application.


Efficacy of the caffeine complex in the treatment of androgenetic alopecia
Conducted at the Clinic of Dermatology and Dermatological Allergology of Friedrich Schiller University in Jena, Germany

Penetration of caffeine from a shampoo formula
Conducted at the Center for Experimental and Applied Skin Physiology and Clinical Research Center for Hair and Skin Physiology of the University Clinic Charité, Berlin.

Differential effects of caffeine on the length of the hair shaft, on the growth and reproduction of keratinocytes, and on growth factors that regulate the hair cycle in male and female human hair follicles in vitro*
Conducted at the Institute for Dermatology at Lübeck University, Germany.

* Original title of study: Differenzielle Effekte von Coffein auf die Länge des Haarschafts, die Keratinozyten-Proliferation der Matrix und der äußeren Wurzelscheide, sowie die TGF-β2-/IGF-1-vermittelte Regulierung des Haarzyklus in männlichen und weiblichen menschlichen Haarfollikeln in vitro.