---
title: "Degarelix"
canonical_url: https://peptidelibrary.app/library/degarelix
description: "Gonadotropin-releasing hormone receptor antagonist approved for advanced hormone-sensitive prostate cancer. Unlike GnRH agonists it lowers testosterone without an initial surge."
updated: 2026-11-07
publisher: Peptide Library
notice: "Research and educational use only. Not medical advice."
---

# Degarelix

Degarelix is an FDA-approved GnRH receptor antagonist. Degarelix binds GnRH receptors on pituitary gonadotrophs competitively and reversibly, immediately blocking the receptor rather than first overstimulating it. Luteinising hormone and follicle-stimulating hormone fall within hours and testosterone follows, avoiding the testosterone flare and the tumour-symptom worsening that can accompany initiation of a GnRH agonist.

Gonadotropin-releasing hormone receptor antagonist approved for advanced hormone-sensitive prostate cancer. Unlike GnRH agonists it lowers testosterone without an initial surge.

## Classification

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

## Mechanism

Degarelix binds GnRH receptors on pituitary gonadotrophs competitively and reversibly, immediately blocking the receptor rather than first overstimulating it. Luteinising hormone and follicle-stimulating hormone fall within hours and testosterone follows, avoiding the testosterone flare and the tumour-symptom worsening that can accompany initiation of a GnRH agonist.

## Properties

- Molecular formula: C82H103ClN18O16
- Molecular weight: 1,632.3 g/mol
- CAS number: 214766-78-6
- Studied routes: Subcutaneous

## Evidence

- Evidence level: FDA Approved
- Highest documented: Regulatory review (FDA label)
- Human trials: 1
- Controlled human trials: 1
- Preclinical sources: 0
- Latest source: 2008

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. FIRMAGON (degarelix for injection) — FDA prescribing information (Ferring), DailyMed. Regulatory label (FDA), human. Population: Patients with advanced prostate cancer. Treatment of advanced prostate cancer [Source](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ab11dd8a-0fd9-4013-89ab-e114557c7e4b)
2. Klotz L et al. The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer. BJU Int. 2008. 2008. Controlled human trial. Population: Men with prostate adenocarcinoma needing androgen deprivation (n=610) [Source](https://pubmed.ncbi.nlm.nih.gov/19035858/)

## Safety

Human safety basis: FDA prescribing information

## Regulatory status

Degarelix 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 Degarelix?

Gonadotropin-releasing hormone receptor antagonist approved for advanced hormone-sensitive prostate cancer. Unlike GnRH agonists it lowers testosterone without an initial surge.

### How does Degarelix work?

Degarelix binds GnRH receptors on pituitary gonadotrophs competitively and reversibly, immediately blocking the receptor rather than first overstimulating it. Luteinising hormone and follicle-stimulating hormone fall within hours and testosterone follows, avoiding the testosterone flare and the tumour-symptom worsening that can accompany initiation of a GnRH agonist.

### Is Degarelix FDA approved?

Yes. Degarelix 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 Degarelix?

Compounds most often compared with Degarelix include Cetrorelix, 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

- [Cambridge Neoadjuvant Cancer of the Prostate (CANCAP03): A Window Study into the Effects of Olaparib ± Degarelix in Primary Prostate Cancer — Clin Cancer Res, 2025](https://pubmed.ncbi.nlm.nih.gov/40358364/)
- [ARNEO: A Randomized Phase II Trial of Neoadjuvant Degarelix with or Without Apalutamide Prior to Radical Prostatectomy for High-risk Prostate Cancer — Eur Urol, 2023](https://pubmed.ncbi.nlm.nih.gov/36167599/)
- [Cardiovascular Safety of Degarelix Versus Leuprolide in Patients With Prostate Cancer: The Primary Results of the PRONOUNCE Randomized Trial — Circulation, 2021](https://pubmed.ncbi.nlm.nih.gov/34459214/)
- [The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer — BJU Int, 2008](https://pubmed.ncbi.nlm.nih.gov/19035858/)
- [Relationship between \[(18)F\]PSMA-1007 PET parameters and biochemical recurrence-free survival in high-risk prostate cancer patients receiving neoadjuvant hormonal treatment — Eur J Nucl Med Mol Imaging, 2026](https://pubmed.ncbi.nlm.nih.gov/41231407/)

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