Mechanism of effect of velvet on reproductive system of male rats by growth hormone will work with hormone gonadotropin. The command from the brain and hypothalamus. To create the gonadotropins PR race sing hormone (GnRH).IGF-1 controls the secretion of GnRH this type of hormone stimulates the pituitary gland to secrete Luteinizing hormone(LH) to stimulate cell layout and Dick hormone testosterone, which is a hormone to create sperm cells. Limitations on the use of the velvet high price is not commonly used in animals.