Background: Hair loss can occur due to disturbances in the follicular cycle. The most common type of hair loss is androgenetic alopecia, which occurs as a result of androgen hormone stimulation of the hair follicles, causing a transition from a long to a short anagen phase and a short to a long telogen phase, then causes miniaturization of the hair follicle and falls out. Robusta green coffee beans contain many compounds, which contain polyphenol (chlorogenic acid) and alkaloid (caffeine) predominantly. These compound has a 5α-reductase inhibitory action, thereby prolonging the anagen phase, promoting hair growth and reducing hair loss. This research was conducted to prove the effectiveness of 45% green robusta coffee beans given topically in increasing hair length growth and inhibiting the increase of 5α-reductase type 1 levels. Methods: This research is an experimental study with a randomized posttest only control group design. In this study, 30 male wistar rats, 9 weeks old, were divided into 3 groups namely, the control group (K) which was exposed to topical testosterone and ethanol 75% as a negative control, group P1 which was exposed to topical testosterone and given the basic ingredients of solution, and group P2 which was exposed to topical testosterone and given solution contain 45% robusta green coffee bean ethanol extract for 21 days. After the treatment was finished, the length of the hair was measured using caliper, and the level of 5α-reductase type 1 was examined using ELISA test. Results: The results showed that the mean hair length in group P2 was 8.24 ± 0,899%, not significantly different from group K 8,645 ± 2,311% and  group P1 8,98 ± 1,885%. The mean level of 5α-reductase type 1 in group P2 467,61 ± 101,82% was significantly different from group K 700,95 ± 197,67% and not significantly different from group P1 579,39 ± 165,76%. Comparative analysis using the One Way Anova test showed that the mean hair length was not significantly different between groups, but the level of 5α-reductase type 1 indicating a significant difference between groups (p value <0,05). Conclusion: Conclusion for this experiment is that the administration of 45% robusta green coffee bean extract solution did not significantly increase hair growth, but proved effective in inhibiting the increase of 5α-reductase type 1 levels in male wistar rats exposed to topical testosterone.

Robusta green coffee bean extract; Coffea canephora; hair length; 5?-reductase type 1