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
Trophic hormone causes hyperplasia of enterochromaffin cells which may transform into carcinoid tumors. Trophic hormone Trophic hormone is a hormone that has a growth effect, hyperplasia or hypertrophy, on the tissue it is stimulating. The term "trophic" is from Ancient Greek τροφικός ("trophikós") meaning "pertaining to food or nourishment", here used to mean "growth"; this is the same origin as "atrophy." This should not be confused with "tropic," as in the similar-sounding tropic hormone – the words and concepts are both unrelated. A key example of this is thyroid-stimulating hormone stimulating the thyroid; excess thyroid-stimulating hormone can create a goitre. Trophic hormones