Efficacy of a cosmetic caffeine shampoo for the treatment of androgenetic alopecia in men

Conducted at the Center for Cosmetic Research of Catholic University of the Sacred Heart in Rome, Italy.

Most men suffering from androgenetic alopecia (hair loss caused by male hormones, abbreviation: AGA) show hair loss with a certain progression pattern that can lead to full baldness. Male-type AGA can manifest any time after puberty, affects almost 50% of 50-year-olds and is due to a genetic predisposition in most cases.

One important factor for the onset of AGA is the hormone dihydrotestosterone (DHT). A hypersensitivity of the hair roots to this hormone decreases the hair root’s energy supply so that the growth cycle is prematurely disrupted. The hair follicles gradually become smaller and are finally destroyed.

The caffeine-containing active ingredient from Alpecin protects the hair roots against the dihydrotestosterone attack and supplies sufficient growth energy. The growth phases are prolonged again, thereby preventing baldness.


A randomised, controlled, double-blind, parallel group trial with 66 healthy men affected by androgenetic alopecia was conducted at the Center for Cosmetic Research at Catholic University in Rome. Skin tolerability, efficacy against hair loss and the cosmetic properties of Alpecin Caffeine Shampoo C1 (hereinafter referred to as “verum”) were tested in comparison to Alpecin Medicinal Shampoo Concentrate for oily hair (hereinafter referred to as “control” meaning a product without caffeine) in a six-month application.

The trial participants had the corresponding age (18 to 55 years), the phototype (Fitzpatrick I-IV), hair resistance against pulling (minimum of 18 hairs) and the Hamilton-Norwood type (II-IV) and were selected according to the study inclusion and exclusion criteria. The participants were randomly divided into one verum and one control group with 33 participants each.

A quantity of 7 ml of shampoo was applied respectively, left on the hair and scalp for two minutes and subsequently rinsed out. After three and six months of treatment, product efficacy was rated using a test subject questionnaire. Skin tolerability was visually assessed and rated using a dermatological questionnaire at the start as well as after three and six months of treatment.

Intensity of hair loss

As part of the trial, no sensitivity or intolerance reactions were observed. Especially after six months of treatment, satisfaction of the verum group who used the Alpecin Caffeine Shampoo C1 was significantly higher at 85% than for the control group at 36%, who had used the Alpecin Medicinal Shampoo Concentrate for oily hair. In the verum group, a distinct improvement of hair loss intensity, a reduced number of hairs in the sink as well as stronger and noticeably thicker hair were observed.

Progression of baldness

The willingness to continue treatment with the corresponding product was significantly greater in the verum group (85%) than for the control (36%). According to information from the investigator, hair strength and thickness and the extent of hair loss were clearly improved in the verum group. Baldness also decreased in the verum group as compared to the control. In summary, the verum reduced premature hair loss in 73% of the verum test subjects but only in 33% of the control test subjects.


Caffeine has proven to be a useful aid in the treatment of androgenetic alopecia that can counteract the inhibition of human hair growth based on dihydrotestosterone. Hair follicles provide a highly efficient path for penetration and a reservoir for topically applicable substances.

The study proves the skin tolerability of Alpecin Caffeine Shampoo C1 (verum) and Alpecin Medicinal Shampoo Concentrate for oily hair (control). In addition, Alpecin Caffeine Shampoo C1 demonstrates good cosmetic efficacy, a decrease in hair loss, a reduction in the number of hairs in the sink, an improvement of hair strength and thickness as well as a reduction in the progression of baldness.

A total of 85% of the test subjects were satisfied with the verum, compared to only 36% with the control, and would continue treatment with the Alpecin Caffeine Shampoo C1. As a result, Alpecin Caffeine Shampoo C1 can be considered an effective cosmetic, growth-stimulating aid in the treatment of AGA.


T. Sisto, C. Bussoletti, L. Celleno, J. Appl. Cosmetol. 2013, 31, 57-66.