PeptideHormone

Cetrorelix

A GnRH antagonist — immediate suppression with no flare.

AnalogEstablishedBased on Gonadotropin-releasing hormoneCompare lineage

Identity

Class
GnRH receptor antagonist (decapeptide)
Source
Synthetic GnRH antagonist
Receptor
GnRH receptor (GnRHR) — competitive antagonist

Key properties

Molecular weight
~1,431 Da
Half-life (native)
~5 h (immediate-release)
Model dosing

Approximate values for the native hormone. Engineered analogs are often deliberately larger and far longer-acting.

Mechanism

Cetrorelix blocks the GnRH receptor directly, so it suppresses gonadotropin release immediately and without the initial flare that agonists cause. This clean, rapid suppression is the key mechanistic contrast with agonists like leuprolide.

Reference notes

  • As an antagonist, it produces immediate suppression — no agonist flare.
  • It is the mechanistic mirror image of GnRH agonists at the same receptor.
  • The flare-vs-no-flare difference is a clear teaching case in receptor pharmacology.

Selected literature

Curated peer-reviewed reviews, sourced from PubMed. Selected for relevance, not exhaustive — open any entry on PubMed for the full record and its primary citations.

  1. 1.The LHRH antagonist cetrorelix: a review · Human reproduction update, 2000 · PMID 10972520
  2. 2.LHRH antagonists · Pharmaceutical biotechnology, 1998 · PMID 9760679