This is from the study: "Selective Inhibition of Steroid 5alpha-Reductase Isozymes by Tea Epicatechin-3-Gallate and Epigallocatechin-3-Gallate", Liao and Hiipakka, Biophys Biochem Res Commun 214:833-838, 1995.
They say near the end of the study: "...We have found that EGCG also reduced 5alpha-DHT production from testosterone by cells in culture. In line with these observations, we have found that EGCG administered to male rats could reduce the weight of male accessory organs, such as ventral prostate, seminal vesicle, and coagulating gland without affecting the weight of testis or kidney. We have also found that topical application of EGCG or gamma-linolenic acid can inhibit sebum production by the male human forehead (unpublished observation)."