---
title: "Cetrorelix"
canonical_url: https://peptidelibrary.app/library/cetrorelix
description: "GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian stimulation."
updated: 2026-11-07
publisher: Peptide Library
notice: "Research and educational use only. Not medical advice."
---

# Cetrorelix

Cetrorelix is an FDA-approved GnRH receptor antagonist. Cetrorelix competitively blocks GnRH receptors on pituitary gonadotrophs, suppressing luteinising hormone secretion within hours and without the initial flare seen with agonists. In assisted reproduction this prevents premature ovulation while allowing follicles to continue developing under exogenous gonadotropin stimulation.

GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian stimulation.

## Classification

- Type: FDA-approved GnRH receptor antagonist
- Mechanism class: GnRH Modulator
- Development stage: Approved product
- Regulatory class: FDA-approved medicine

## Mechanism

Cetrorelix competitively blocks GnRH receptors on pituitary gonadotrophs, suppressing luteinising hormone secretion within hours and without the initial flare seen with agonists. In assisted reproduction this prevents premature ovulation while allowing follicles to continue developing under exogenous gonadotropin stimulation. The effect is dose-dependent and reverses on discontinuation.

## Properties

- Molecular formula: C70H92ClN17O14
- Molecular weight: 1,431 g/mol
- Studied routes: Subcutaneous

## Evidence

- Evidence level: FDA Approved
- Highest documented: Regulatory review (FDA label)
- Human trials: 1
- Controlled human trials: 0
- Preclinical sources: 0
- Latest source: 2000

Each step shows whether the sources Peptide Library has reviewed include that kind of research. Counts are reviewed sources, not every study ever published. Reviews and programme summaries that describe human use are shown as "reported", not as trials, and registered trials without published results are listed but not counted. A higher step means research has progressed further; it does not mean a compound works better or is safer. Compounds whose evidence has not been reviewed yet show "Not reviewed" instead of a guess.

### Studies

1. Cited source (title omitted: it states a dose). Regulatory label (FDA), human. Population: Women undergoing controlled ovarian stimulation. Inhibition of premature LH surges [Source](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aca7768e-28a7-4027-b1d8-e66247665f79)
2. Mettler L, Brandenburg K. Clin Exp Obstet Gynecol. 2000. 2000. Human study (early or uncontrolled). Population: Women having ovarian stimulation with recombinant FSH for IVF or ICSI (n=26). Mean 5.5 oocytes retrieved in 24 patients; pregnancy in 10 patients [Source](https://pubmed.ncbi.nlm.nih.gov/10968345/)

## Safety

Human safety basis: FDA prescribing information

## Regulatory status

Cetrorelix is an FDA-approved product for specific labelled indications. Approval does not extend to the research contexts described on this page, and approved products are prescription medicines.

- FDA status: Approved
- Availability: Prescription-Only

## Frequently asked questions

### What is Cetrorelix?

GnRH receptor antagonist approved to prevent premature luteinising hormone surges in women undergoing controlled ovarian stimulation.

### How does Cetrorelix work?

Cetrorelix competitively blocks GnRH receptors on pituitary gonadotrophs, suppressing luteinising hormone secretion within hours and without the initial flare seen with agonists. In assisted reproduction this prevents premature ovulation while allowing follicles to continue developing under exogenous gonadotropin stimulation.

### Is Cetrorelix FDA approved?

Yes. Cetrorelix is approved by the FDA, and approved products are prescription medicines. Approval is always for specific indications studied in clinical trials, so an approved status does not mean the compound is approved for every use it is discussed for. Research-chemical material sold under the same name is not the approved product.

### What peptides are similar to Cetrorelix?

Compounds most often compared with Cetrorelix include Degarelix, Ganirelix, Leuprolide and Gonadorelin. They are grouped by shared mechanism or research area rather than by equivalence, and their regulatory status and evidence base differ.

## References

- [Efficacy of GnRH antagonists in the treatment of uterine fibroids: a meta-analysis — Arch Gynecol Obstet, 2025](https://pubmed.ncbi.nlm.nih.gov/39821450/)
- [Source](https://pubmed.ncbi.nlm.nih.gov/10968345/)
- [Delayed Start Versus Conventional GnRH Antagonist Protocol in Poor Responders Pretreated With Estradiol in Luteal Phase: A Randomized Controlled Trial — Reprod Sci, 2015](https://pubmed.ncbi.nlm.nih.gov/26045549/)
- [Cetrorelix in reproductive medicine — F S Rep, 2023](https://pubmed.ncbi.nlm.nih.gov/37223762/)
- [The LHRH antagonist cetrorelix: a review — Hum Reprod Update, 2000](https://pubmed.ncbi.nlm.nih.gov/10972520/)

Note: Dose figures are left out of this Markdown version. See the cited sources.