Estrone acetate (Hogival) is an estrogen derivative and an activator of estrogen receptors (ER). This compound can enhance breast development, stimulate the secretion of pituitary prolactin, and induce both the proliferation and activation of lactotrophs, evidenced by the reduction in prolactin storage granule size and the increase in the volume density of the rough endoplasmic reticulum and Golgi apparatus. Estrone acetate holds potential for endocrinological research and for investigating the mechanisms by which estrogen influences pituitary function, prolactin regulation, and breast tumor models.