The most potent androgen, required for sex development. Dihydrotestosterone is synthesised from testosterone in the prostate gland, testes, hair follicles and adrenal glands by 5-alpha reductase. Dihydrotestosterone exerts its action similar to testosterone, which binds to and activates specific nuclear androgen receptors. After translocation into the nucleus, the activated hormone-receptor complex binds to the androgen response elements on the DNA and activates gene expressions that are required for sex development. Dihydrotestosterone is responsible for the formation of male primary sex characteristics and most male secondary sex characteristics during puberty, such as muscular growth, facial and body hair growth, and deepening of the voice.