Comparison
Degarelix vs. Nafarelin
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Research other
CAS no.
214766-78-6
no data
Molecular weight
1632.3 g/mol
no data
Half-life
1320 h
no data
Sequence
Ac-D-2Nal-D-4Cpa-D-3Pal-Ser-4Aph(Hor)-D-4Aph(Cbm)-Leu-Ilys-Pro-D-Ala-NH2no data
Mechanism of action
Degarelix
Degarelix is a competitive GnRH receptor antagonist. It binds reversibly and immediately to the pituitary GnRH receptors and blocks their activation. This rapidly suppresses the release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn lowers testosterone production in the testes. Unlike GnRH agonists (e.g., leuprorelin), which first cause a transient stimulation with a testosterone surge (flare), this direct antagonism lacks the initial stimulation phase, so testosterone declines without a preceding rise. This mechanism underlies the literature-described use in hormone-dependent prostate cancer.
Nafarelin
Nafarelin is a potent GnRH agonist: after an initial stimulation ('flare'), continuous receptor occupancy leads to downregulation and thereby suppression of LH, FSH and the downstream sex hormones.
Evidence base
Highest evidence
Human RCT
Human RCT
Studies
4
0
of which in humans
4
0
Effects recorded
4
2
Open conflicts
1
0
Documented adverse events
2
1
Legal status
Full entries
Frequently asked questions
- What is the difference between Degarelix and Nafarelin?
- Degarelix is classified as "Research other", while Nafarelin is classified as "Research other". Degarelix: Degarelix (trade name Firmagon) is a synthetic decapeptide and a gonadotropin-releasing hormone (GnRH) receptor antagonist. Unlike GnRH agonists, it blocks the receptor directly and does not trigger an initial testosterone surge (flare). It is an approved prescription medicine for the treatment of advanced, hormone-dependent prostate cancer. This page neutrally summarizes the evidence base and legal status and is not a usage or dosing recommendation. Nafarelin: Nafarelin is a GnRH agonist and the only member of this class delivered as a nasal spray. It is approved for treating endometriosis and central precocious puberty. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
- Which peptide is better supported by science, Degarelix or Nafarelin?
- The highest available evidence level is "Human RCT" for Degarelix and "Human RCT" for Nafarelin. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
- What is the legal status of Degarelix and Nafarelin in Germany and the United States?
- Germany: Degarelix — Prescription, Nafarelin — Prescription. United States: Degarelix — Prescription, Nafarelin — Prescription. These are factual summaries with source and review date on the individual pages.