What are the effects of dihydrotestosterone. Dihydrotestosterone is an androgen produced by the reaction between testosterone and alpha-reductase in human body, which is widely distributed in the blood of the whole body. Therefore, the role of dihydrotestosterone is mainly: firstly, to maintain the role of spermatogenesis. Secondly, it stimulates the development of reproductive organs, promotes the emergence of male secondary sex characteristics and maintains their normal shape. Thirdly, it maintains normal sexual desire. Fourth, it promotes the synthesis of proteins, especially the synthesis of proteins of muscles and reproductive organs, and also promotes the growth of bones and the deposition of calcium and phosphorus, and the production of red blood cells.