Blocks GnRH receptors directly — no initial hormone flare, unlike agonists.
Also known as: Cetrotide · GnRH antagonist
Part of the Foundational & therapeutic peptides cluster
Overview
Cetrorelix is a synthetic decapeptide GnRH antagonist that competitively blocks the GnRH receptor. It is an approved prescription medicine used in in-vitro fertilization to prevent premature luteinizing hormone surges. This page is educational and is not medical advice.
Source & context
Biological / chemical source: Synthetic decapeptide analog of GnRH
Primary research or clinical context: Approved medicine used in assisted reproduction to prevent premature luteinizing hormone surges (prescription)
Antagonist vs. agonist
Unlike GnRH agonists, which cause an initial hormone surge before suppression, antagonists like cetrorelix block the receptor immediately. This rapid, flare-free suppression is valued in fertility protocols where precise timing of the LH surge matters.
Design
Cetrorelix incorporates multiple non-natural amino-acid substitutions across the GnRH decapeptide backbone. These changes convert the natural agonist into a stable competitive antagonist while resisting enzymatic degradation.
FAQ about Cetrorelix
What is Cetrorelix?+
Cetrorelix is a synthetic decapeptide GnRH antagonist that competitively blocks the GnRH receptor. It is an approved prescription medicine used in in-vitro fertilization to prevent premature luteinizing hormone surges. This page is educational and is not medical advice.
Is Cetrorelix an approved medicine?+
Cetrorelix: Approved medicine used in assisted reproduction to prevent premature luteinizing hormone surges (prescription). Always follow licensed medical guidance for approved products.
What is the typical length of Cetrorelix?+
Cetrorelix is commonly described as approximately 10 amino acids (GnRH antagonist (decapeptide analog)).