Degarelix is a competitive and reversible gonadotropin-releasing hormone receptor (GnRHR) antagonist.

Degarelix directly acts on the pituitary receptors to luteinizing hormone-releasing hormone (LHRH), preventing the effect of endogenous LHRH. The use of degarelix eliminates the undesirable surge of initial gonadotropin and testosterone levels produced by LHRH agonists. With the exception of PC-3 cells, Degarelix treatment reduces the cell viability of all prostate cell lines (WPE1-NA22, WPMY-1, BPH-1 cells, VCaP cells). GnRH antagonist degarelix has a direct effect on the growth of prostate cells through apoptosis.

In a single subcutaneous injection of 0.3 to 10 μg/kg in rats, degarelix produced a dose-dependent inhibition of the pituitary-gonad axis as revealed by the decrease in plasma luteinizing hormone (LH) and testosterone levels. The duration of LH inhibition increased with increasing dose: in rats, after subcutaneous injection of digarelix 12.5, 50 or 200 μg/kg, the significant inhibition of LH lasted 1, 2 and 7 days, respectively [ 3]. Degarelix is stable when incubated in microsomes and liver cells cryopreserved in animal liver tissue.