In the body, dihydrotestosterone (DHT) acts as one of the most potent androgenic hormones. The prohormone testosterone takes on this function in skeletal muscle tissue. Testosterone, in tissues rich in the enzyme 5-alpha reductase (5-AR), converts to DHT. These tissues include the central nervous system (CNS), skin and gonads. DHT displays several different effects when coupled with other hormones. DHT generally exhibits a positive effect on sexual function and sex drive. The mechanism by which this is achieved results from one or a combination of pathways.
DHT forms naturally in the body from testosterone, especially in androgen dependent tissues, besides muscle tissue. When testosterone enters neural tissue, skin, or endocrine tissue it converts to DHT under the catalytic properties of 5-AR. In a 5-AR deficient environment, sufficient amounts of DHT would not be produced, causing serious physical and physiological malformations.
Researchers studied a congenital disorder that limits DHT development in children. Pseudohermaphroditism results from deficiency in the enzyme 5-AR. Children with the disorder display "ambiguous genitalia and are often raised as girls." At the onset of puberty, testosterone levels increase as expected, while DHT levels remain stunted. Muscle development proceeds as usual, however secondary male sexual characteristics, such as body and pubic hair growth, do not and they also have underdeveloped prostate glands and penises. As a result, the disorder affects their sexual function and libido.
DHT and Estrogen
In both men and women, high levels of oestrogen show correlation to decreased sex drive, while higher ratios of androgens will result in increased libido. DHT balances oestrogen levels in the body. DHT prevents oestrogen from acting on tissues by either blocking androgen receptors in the tissue or blocking RNA transcription after oestrogen has bound to the receptors.
A common misconception about DHT remains that its presence in the prostate causes hypertrophy in that tissue. In actuality, evidence shows that high levels of oestrogen correlate to hypertrophy in the prostate. Older men tend to display higher oestrogen to androgen ratios, therefore, they may experience prostate enlargement and decreased libido. So higher levels of DHT should prevent such issues.
DHT and Libido
DHT's status as a highly active androgen hormone causes an increase in sex drive, especially in individuals using supplemental amounts of it. Its inhibition of oestrogen in the body also causes the increase in sexual desire. In growing individuals, it acts to develop secondary sexual characteristics.
This positive correlation is in no way a recommendation for its extraneous use outside of a doctor's supervision.