Head to head
Cetrorelix against Degarelix
Two GnRH antagonists used in completely different settings, preventing premature ovulation in fertility treatment and suppressing testosterone in prostate cancer. Same mechanism, different dose, different duration, and no reason to substitute one for the other.
Column A
CetrorelixCetrorelix (GnRH antagonist)
An FDA-approved GnRH antagonist used in fertility treatment to prevent premature ovulation.
Column B
DegarelixDegarelix (Firmagon), GnRH receptor antagonist
A GnRH antagonist approved in 2008 for advanced prostate cancer. In its 610-patient phase 3, testosterone was at or below 0.5 ng/mL by day 3 in about 96 percent of degarelix patients and in none of the leuprolide patients, and it met non-inferiority over 12 months. Injection site reactions occurred in 40 percent versus under 1 percent with intramuscular leuprolide, and the trial designed to test whether it is safer for the heart was terminated early and found no difference.
Side by side, on the facts we can check
| Attribute | Cetrorelix | Degarelix |
|---|---|---|
| Category | Hormone | Hormone |
| FDA status | FDA-approved (Cetrotide) | FDA-approved on 24 December 2008 under NDA 022201, marketed as Firmagon, for treatment of patients with advanced prostate cancer. No boxed warning. Not approved for localised prostate cancer management outside that indication, for any use in women, or for any use in healthy adults. |
| Half-life | ~5-63 hours (formulation dependent) | About 53 days terminal, driven by slow release from the subcutaneous depot. |
| Molecular weight | 1,431.1 Da | About 1632 Da as the free base, per the label. A decapeptide with five D-amino acids. |
| Mechanism | Competitively blocks GnRH receptors, producing immediate suppression of LH and FSH release. | Direct competitive antagonism at the pituitary GnRH receptor. Blocking the receptor stops luteinising hormone and follicle-stimulating hormone release immediately, so testosterone falls within days with no initial surge. This is the mechanistic opposite of the agonists leuprolide, goserelin and triptorelin, which produce their suppression by first overstimulating the same receptor. Degarelix also forms a subcutaneous depot at the injection site from which it releases slowly, which explains both the long terminal half-life and the high rate of local reactions. |
| Human studies cited | 2 | 3 |
| Legal status, US | FDA-approved, prescription only | FDA-approved, prescription only |
Frequently asked questions
What is the difference between Cetrorelix and Degarelix?
Cetrorelix: An FDA-approved GnRH antagonist used in fertility treatment to prevent premature ovulation. Degarelix: A GnRH antagonist approved in 2008 for advanced prostate cancer. In its 610-patient phase 3, testosterone was at or below 0.5 ng/mL by day 3 in about 96 percent of degarelix patients and in none of the leuprolide patients, and it met non-inferiority over 12 months. Injection site reactions occurred in 40 percent versus under 1 percent with intramuscular leuprolide, and the trial designed to test whether it is safer for the heart was terminated early and found no difference.
Which has stronger research evidence, Cetrorelix or Degarelix?
This database does not grade compounds. It counts what was run in people: 2 of the 3 studies cited on the Cetrorelix profile were human work, against 3 of 3 for Degarelix. Those counts are of our own citation lists and understate any larger literature, and neither is a recommendation.
Are Cetrorelix and Degarelix FDA-approved?
Cetrorelix: FDA-approved (Cetrotide). Degarelix: FDA-approved on 24 December 2008 under NDA 022201, marketed as Firmagon, for treatment of patients with advanced prostate cancer. No boxed warning. Not approved for localised prostate cancer management outside that indication, for any use in women, or for any use in healthy adults..
Reviewed Sep 2026. This page sets two published records side by side. It is educational, it is not medical advice, and it contains no dosing protocols or recommendations for personal use.