The following are commonly used: Continuous combination (estrogen-progestin) contraceptives The following drugs are usually used only when women cannot take combination oral contraceptives or when treatment with combination oral contraceptives is ineffective: Progestins Gonadotropin-releasing hormone (GnRH) agonists and antagonists Danazol Table GnRH agonists initially increase hypothalamic GnRH secretion, but continued use then temporarily decreases pituitary release of follicle-stimulating hormone (FSH), resulting in a decreased in estrogen production by the ovaries; however, treatment is limited to ≤ 6 months because long-term use may result in bone loss.