[6] The GnRH antagonist degarelix, through its ability to reduce serum testosterone, is used to treat hormone-sensitive prostate cancer.

Injection-site reactions are usually mild or moderate in intensity and occur predominantly after the first dose, decreasing in frequency thereafter.

Measuring PSA levels helps to monitor how patients with prostate cancer are responding to treatment.

[medical citation needed] Unlike GnRH agonists, which cause an initial stimulation of the hypothalamic-pituitary-gonadal axis (HPGA), leading to a surge in testosterone levels, and under certain circumstances, a flare-up of the tumour, GnRH antagonists do not cause a surge in testosterone or clinical flare.

As testosterone surge does not occur with GnRH antagonists, there is no need for patients to receive an antiandrogen as flare protection during prostate cancer treatment.

[medical citation needed] In December 2008, the US Food and Drug Administration (FDA) approved degarelix for the treatment of people with advanced prostate cancer.

[15] A study demonstrated a reduced the risk score for committing child sexual abuse in men with pedophilic disorder two weeks after initial injection.