cetrorelix + leuprolide

This is a combination of two synthetic hormones that affect the gonadotropin-releasing hormone (GnRH) system but through different mechanisms. Cetrorelix is a GnRH antagonist that competitively binds to GnRH receptors, preventing natural GnRH from interacting with its receptors. This results in the suppression of luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels within 8 hours after injection. Leuprolide is a GnRH receptor superagonist that, after an initial spike in GnRH-mediated steroidal production, causes a significant drop in circulating steroid levels with prolonged use. The combination has been studied for preventing premature LH surges in women undergoing controlled ovarian stimulation for assisted reproduction therapy.