Orgasm men are capable of achieving them is supported by men who have reported having multiple, consecutive orgasms, particularly without ejaculation. Males who experience dry orgasms can often produce multiple orgasms, as the refractory period is reduced. An increased infusion of the hormone oxytocin during ejaculation is believed to be chiefly responsible for the refractory period, and the amount by which oxytocin is increased may affect the length of each refractory period. Another chemical which is considered to be responsible for the male refractory period is prolactin, which represses dopamine, which is responsible for sexual arousal. Because of this, there is
Growth hormone by the FDA. GH has been studied for use in raising livestock more efficiently in industrial agriculture and several efforts have been made to obtain governmental approval to use GH in livestock production. These uses have been controversial. In the United States, the only FDA-approved use of GH for livestock is the use of a cow-specific form of GH called bovine somatotropin for increasing milk production in dairy cows. Retailers are permitted to label containers of milk as produced with or without bovine somatotropin. The names "somatotropin" ("STH") or "somatotropic hormone" refer to the growth hormone produced naturally in animals