Degarelix (Firmagon)_Dosage, benefits & legal status
Also known as Firmagon
A GnRH antagonist for prostate cancer, and the one with no testosterone flare.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Degarelix (Firmagon)?
Plain language first. The technical label stays, but it never stands alone.Overview
Drops testosterone straight away for prostate cancer, with none of the initial surge the older drugs cause. That surge is dangerous for some men, which is the whole reason this exists.
Degarelix, a GnRH receptor antagonist producing immediate suppression of gonadotropins and testosterone without an initial flare. FDA-approved 2008 for advanced prostate cancer. Administered as a subcutaneous loading dose followed by monthly maintenance.
What it's used for
A prescription drug for advanced prostate cancer, giving immediate testosterone suppression.
How does Degarelix (Firmagon) work?
What it does in the body, and where.Degarelix exists because the flare that leuprolide causes is a genuine clinical problem in some patients.
- 01Immediate blockade, no flareAs a receptor antagonist it suppresses gonadotropins from the first dose. Testosterone falls within days rather than after an initial surge.
- 02The flare it avoids can be dangerousIn men with spinal metastases or urinary obstruction, a testosterone surge can worsen the situation quickly. That is the clinical scenario where an antagonist is preferred over an agonist.
- 03It is dosed monthly after a loading doseA larger starting dose is followed by monthly maintenance, given subcutaneously.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Advanced prostate cancerFDA-approved
- Situations where the testosterone flare from an agonist would be dangerousClinical use
The published record
Papers and trials about Degarelix (Firmagon)
342 papers tagged human · 177 not reviews or lab · 64 clinical trial publications
170 registered trials · 28 with posted results
Furthest stage reached: Approved in the US
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count. 400 papers and 100 trials indexed in detail.
At a glance
Four things to know about Degarelix (Firmagon)
Evidence
FDA-approved
Category
Sexual and hormonal
Common vial
Varies
Half-life
About 53 days
How much, and do you cycle it?
The range, and whether you take breaks.Set by the label, loading dose, then monthly. Set by the prescription FDA label
This is a prescription drug. Duration and schedule are set by the label and the prescriber, not by a cycling convention.
About 53 daysFDA label
Median terminal half-life in prostate cancer patients, clearing in two phases. The long figure is not slow clearance. Degarelix forms a depot under the skin and releases slowly from it, which is what makes monthly dosing possible.
Source: Firmagon label section 12.3
You can compare this against the whole library to see where it sits.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
How do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized Degarelix (Firmagon) keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.Solubility, computed: 30% charged residues, 80% hydrophobic. Water usually sufficient.
A first-pass rule from peptide manufacturers' guidance. It does not account for disulfide bridges, salt form or how the powder was dried, and it predicts what should be easy rather than what will happen in your vial.
Who should avoid it
- Known hypersensitivity to degarelix or any component
- Pregnancy, which does not apply to its approved population but matters for handling
- Use outside a prescription, where no label governs the dose
Stop and get help
- Signs of an allergic reaction, including facial or throat swelling or trouble breathing
- Severe or spreading injection site reaction
- Yellowing of the skin or eyes
Common effects
- Injection site pain, redness and swelling
- Hot flushes
- Weight gain
- Raised liver enzymes
- Reduced libido and sexual function
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Degarelix (Firmagon) approved?
And where the numbers on this page come from.Yes. Degarelix (Firmagon) is FDA approved and available on prescription in the United States.
- Approval statusFDA-approved
- RouteUnder the skin (subcutaneous)
- Checked24 August 2026
- DoseFrom the drug label. The manufacturer tested this range and a regulator reviewed it.
- Vial sizeFrom what vendors typically list; not a recommendation.
- SourcesNone traced yet.
What has happened recently
FDA-approved 2008 as Firmagon for advanced prostate cancer. Prescription only.
You can compare this against the whole library, or read how to check a seller.
What else is like Degarelix (Firmagon)?
Others in Sexual and hormonal, side by side.If you're weighing Degarelix (Firmagon), it's worth reading Desmopressin (DDAVP), ENDO-205, and Goserelin (Zoladex) in the same class.
A GnRH antagonist for prostate cancer, and the one with no testosterone flare.
- Dose
- Set by the label
- How often
- Loading dose, then monthly
A vasopressin analog with more FDA approvals than any other peptide, and a real hyponatremia risk.
- Dose
- Set by the label and the formulation
- How often
- Varies by indication
An experimental non-hormonal peptide for endometriosis with an FDA-cleared IND and no human data yet.
- Dose
- No human dose disclosed
- How often
- Not established
A GnRH agonist given as an implant under the skin rather than an injection.
- Dose
- Set by the label
- How often
- Monthly or 3-monthly implant
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
Sources
No primary source has been traced for this compound yet. Treat everything on this page as unverified until one is. How we grade evidence
Beyond these, 500 records are indexed. Browse the records