Sexual desire have been associated with a decline in sexual desire. Though it is not used as medication, the drug methamphetamine has a strong positive effect on many aspects of sexual behaviour, including sexual desire. Sexual desire is said to be influenced by androgens in men and by androgens and estrogens in women. Many studies associate the sex hormone, testosterone with sexual desire. Testosterone is mainly synthesized in the testes in men and in the ovaries in women. Another hormone thought to influence sexual desire is oxytocin. Exogenous administration of moderate amounts of oxytocin has been found to stimulate females to desire
Transgender hormone therapy (male-to-female) produce full progestogenic effects with oral administration. Some progestins, such as medroxyprogesterone acetate and hydroxyprogesterone caproate, are or can be used by intramuscular or subcutaneous injection instead. Almost all progestins, with the exception of dydrogesterone, have antigonadotropic effects. The main effects of hormone therapy in transgender women are feminization and demasculinization, and are as follows: Breast, nipple, and areolar development varies considerably depending on genetics, body composition, age of HRT initiation, and many other factors. Development can take a couple years to nearly a decade for some. However, many transgender women report there is often a "stall" in breast growth