Buserelin
（重定向自Suprefact）
Buserelin (INN) is a gonadotropin-releasing hormone agonist (GnRH agonist). The drug's effects are dependent on the frequency and time course of administration. GnRH is released in a pulsatile fashion in the postpubertal adult. Initial interaction of any GnRH agonist, such as buserelin, with the GnRH receptor induces release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) by gonadotrophes. Long-term exposure to constant levels of buserelin, rather than endogenous pulses, leads to downregulation of the GnRH receptors and subsequent suppression of the pituitary release of LH and FSH.