Prolactin (PRL) is secreted from the pituitary gland in response to eating, mating, and ovulation. Increased serum concentration of PRL during pregnancy contributes to enlargement of the mammary glands of the breasts and prepares for production of milk. However, high PRL levels derived from prolactinoma and hyperprolactinemia induce physiological disorders such as infertility and early menopause. Natural compounds isolated from S. chinensis have been known to possess anti-oxidative, anti-inflammatory and anti-diabetic effects. In the present study, we examined the therapeutic effect of S. chinensis and its single compounds on hyperprolactinemia in the pituitary gland. In rat pituitary cells, PRL expression levels were examined using real-time PCR and western blot assay. Crude S. chinensis extract and its single compound, gomisin N, reduced mRNA and protein levels of PRL in GH3 cells. In addition, cell proliferation and PRL target gene expression in cells were modulated by S. chinensis. Similar to the in vitro experiments, crude S. chinensis extract and gomisin N reduced PRL levels in the pituitary and serum of immature female rats. These results show that S. chinensis and its single compound, gomisin N, are regulators of PRL production and may be candidates for treatment of hyperprolactinemia and prolactinoma.