A GnRH antagonist that lowers testosterone without the initial hormone flare.
Also known as: Firmagon
Part of the Foundational & therapeutic peptides cluster
Overview
Degarelix is a synthetic decapeptide GnRH receptor antagonist approved for advanced hormone-dependent prostate cancer. Unlike GnRH agonists, it blocks the receptor directly and suppresses testosterone rapidly without the transient flare, and it received FDA approval in 2008. This page is educational only.
Source & context
Biological / chemical source: Synthetic decapeptide derivative of GnRH
Primary research or clinical context: Approved for advanced hormone-dependent prostate cancer
Antagonist versus agonist
Because degarelix competitively blocks the GnRH receptor rather than over-stimulating it, gonadotropin and testosterone levels fall within days and there is no testosterone surge. This contrasts sharply with agonists such as leuprolide and is a key teaching example in endocrine pharmacology.
Peptide chemistry
Degarelix incorporates several non-natural D-amino acids that resist enzymatic breakdown and form a slow-release subcutaneous depot. Its design shows how substituting unnatural residues extends peptide half-life and reshapes receptor behavior.
FAQ about Degarelix
What is Degarelix?+
Degarelix is a synthetic decapeptide GnRH receptor antagonist approved for advanced hormone-dependent prostate cancer. Unlike GnRH agonists, it blocks the receptor directly and suppresses testosterone rapidly without the transient flare, and it received FDA approval in 2008. This page is educational only.
Is Degarelix an approved medicine?+
Degarelix: Approved for advanced hormone-dependent prostate cancer. Always follow licensed medical guidance for approved products.
What is the typical length of Degarelix?+
Degarelix is commonly described as approximately 10 amino acids (GnRH antagonist).