Antigonadotropin

The best-known and widely used antigonadotropins are the gonadotropin-releasing hormone (GnRH) analogues (both agonists and antagonists). However, many other drugs have antigonadotropic properties as well, including compounds acting on sex steroid hormone receptors such as progestogens, androgens, and estrogens (due to negative feedback on the HPG axis), as well as steroid synthesis inhibitors such as danazol and gestrinone. Since progestins have relatively little effect on sexual differentiation compared to the other sex steroids, potent ones such as cyproterone acetate, medroxyprogesterone acetate, and chlormadinone acetate are often used at high doses specifically for their antigonadotropic effects.

Danazol, gestrinone, and paroxypropione have all been classified specifically as antigonadotropins.

Prolactin has antigonadotropic effects and hyperprolactinemia can cause hypogonadism.

Opioids have antigonadotropic effects and can reduce luteinizing hormone and testosterone levels in men. A 2015 systematic review and meta-analysis found that opioid therapy decreased testosterone levels in men by about 165 ng/dL (5.7 nmol/L) on average, which was a reduction in testosterone level of almost 50%. In contrast to opioids, opioid antagonists, like naltrexone, have progonadotropic effects, and can increase luteinizing hormone and testosterone levels.