Source: FDA label
| Molecular formula | C82H103ClN18O16 |
|---|---|
| Molecular weight | 1632.3 g/mol |
| Registered trials | 174 |
| PubChem CID | 16136245 |
| Brand names | FIRMAGON |
Mechanism of Action
12.1 Mechanism of Action Degarelix is a GnRH receptor antagonist. It binds reversibly to the pituitary GnRH receptors, thereby reducing the release of gonadotropins and consequently testosterone.
Men diagnosed with advanced prostate cancer often want to understand how hormone-blocking therapy actually works before starting it. Degarelix is one option in this category, and its approved label spells out both its mechanism and its safety profile in detail.
Key takeaways
- Degarelix is a GnRH receptor antagonist sold under the brand name FIRMAGON.
- It is approved for treatment of patients with advanced prostate cancer.
- It works by directly blocking pituitary GnRH receptors to lower testosterone.
- More than 170 registered trials have studied degarelix across various prostate cancer settings.
- The most frequently reported reactions involve injection site effects and general fatigue.
What Degarelix Is
Degarelix belongs to the class of GnRH receptor antagonists. Rather than initially stimulating hormone release, it binds reversibly to pituitary GnRH receptors right away. This action reduces the release of gonadotropins, which in turn lowers testosterone production.
What Degarelix Is Approved For
FIRMAGON is indicated for the treatment of patients with advanced prostate cancer. The label does not carry a boxed warning. No other brand names or indications are listed.
What the Evidence Shows
Degarelix has been studied in 174 registered clinical trials. One early-phase trial examined chemohormonal therapy followed by prostatectomy in high-risk prostate cancer and has since completed. A completed Phase 2 study looked at combining abiraterone with discontinuation of GnRH analogues in metastatic prostate cancer. A separate completed study, an intensive drug monitoring program for FIRMAGON, has also concluded.
Reported Side Effects
Reported reactions reflect submitted cases, not confirmed rates or direct causation. The most commonly reported effects center on the injection site, including pain, erythema, and swelling. Systemic reports of fatigue, hot flush, and asthenia were also common. Reports of death and product storage error were logged as well, each with 209 reports.
FAQ
What is degarelix used for?
Degarelix, sold as FIRMAGON, is approved for treatment of patients with advanced prostate cancer. It is a GnRH receptor antagonist that works by lowering testosterone production.
How does degarelix work?
Degarelix binds reversibly to GnRH receptors in the pituitary gland. This reduces the release of gonadotropins, which lowers the amount of testosterone the body produces.
Does degarelix carry a boxed warning?
No, the FIRMAGON label does not carry a boxed warning.
What are the most commonly reported side effects of degarelix?
The most frequently reported reactions involve the injection site, such as pain, erythema, and swelling, along with fatigue, hot flush, and asthenia. These figures come from adverse event reports, which reflect submitted cases rather than confirmed rates or proof of causation.
How much clinical research exists on degarelix?
Degarelix has been studied in 174 registered clinical trials, including work in high-risk and metastatic prostate cancer settings as well as post-market drug monitoring.
This page is an editorial information resource. It does not sell, prescribe, or recommend any medication.
Content is editorial information, not medical advice. Talk to your doctor before any treatment decision.
Sources: DailyMed label (FIRMAGON) ClinicalTrials.gov FDA Adverse Event Reporting System (FAERS) PubChem CID 16136245
Updated 2026-09-26