[4] GnRH agonists are also sometimes used in reproductive therapy, as well as to treat disorders involving sex-steroid hormones, such as endometriosis.

Ganirelix prevents ovulation until it is triggered by injecting human chorionic gonadotrophin (hCG).

[4] Clinical studies have shown that the most common side effect is a slight reaction at the site of injection in the form of redness, and sometimes swelling.

In some rare cases, less than 1 user in 10,000, hypersensitivity to ganirelix can cause anaphylactoid reactions, most likely due to allergy.

Ganirelix competitively blocks GnRH receptors on the pituitary gonadotroph, quickly resulting in the suppression of gonadotropin secretion.

A study administering ganirelix to healthy adult females (n=15) found the mean (SD) elimination half-life (t1/2) to be 16.2(1.6) hours, volume of distribution/absolute bioavailability (Vd/F) 76.5(10.3) liters, maximum serum concentration (Cmax) 11.2(2.4) ng/mL, and the time until maximum concentration (tmax) 1.1(0.2) hours.