Degarelix dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
Degarelix is a hormone blocker approved in 2008 for advanced prostate cancer.
Evidence grade for Degarelix: Moderate. The rule: at least one finished study in people, and at least 100 people who took it. The sum on this page: 2 completed trials, 610 people given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 610
- Human studies
- 2
- Found nothing
- 0
Dose
Approved medicine. No human dose established for unlabelled uses
Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose.
FDA-approved on 24 December 2008 under NDA 022201, sold as Firmagon, to treat advanced prostate cancer. No boxed warning. Not approved for any use beyond that, including prostate cancer that has not spread, any use in women, or any use in healthy adults.
3 effects reported, 3 unwanted, by people using it, not a trial
Goal pages: Hormones and growth hormone, Heart and circulation
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Degarelix is a monthly shot for advanced prostate cancer. It blocks the signal that tells the body to make testosterone. It works within days, with no first burst of testosterone. That is its whole approved use.
What people take it for
- Lowering testosterone fast in advanced prostate cancer.
- Avoiding the testosterone flare of the older drugs.
- Being easier on the heart, which has not been shown.
What studies in people showed
In 610 men with prostate cancer, testosterone was shut down by day 3 in about 96 percent on degarelix. On the older drug, leuprolide, it was none. Over 12 months, both held testosterone down just as well. But 40 percent had reactions where the shot went in, against under 1 percent on leuprolide. A heart safety study was stopped early, after 545 of 900 men. It found 15 heart events on degarelix and 11 on leuprolide. That is too few to say either way.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- In the main study, 40 percent had pain, redness or swelling where the shot went in.
- Hot flushes and rises in liver enzymes each show up in 10 percent or more.
- It stays in the body for weeks, so side effects do not stop fast.
Where these come from: We have no user reports. The side effects are from the main study and the label figures on this page.
My bottom line
Fast and effective for the one thing it is for. The heart question is still open. This is a call for your cancer doctor, not a forum.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Degarelix has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Testosterone and male hormones610 people · 1 study
- Heart attacks and strokesno headcount stated · 1 study
34 of the 36 indexed goals have no study of any kind behind Degarelix
No study in people, animals or cells on this page reports a result for these. That does not prove Degarelix does nothing for them. It does mean anything you have heard about Degarelix and one of these did not come from a study cited here.
Show full evidence
What is Degarelix?
Degarelix is a hormone blocker approved in 2008 for advanced prostate cancer. In its main study of 610 men, testosterone was down to castration level by day 3 in about 96 percent on degarelix, and in none on the older drug, leuprolide. Over 12 months it held testosterone down just as well. 40 percent had reactions where the shot went in, against under 1 percent on leuprolide. The study built to test whether it is easier on the heart was stopped early and found no difference.
Degarelix is a man-made chain of ten building blocks. Five of them are mirror-image forms. It blocks the GnRH receptor directly, instead of overworking it. The FDA approved it on 24 December 2008 for advanced prostate cancer. That one short line is its whole approved use.
The case for blockers like this is speed, and no flare. Because the receptor is blocked, not worn out, testosterone falls right away. In the main study, by day 3, testosterone was at or below the castration line of 0.5 ng/mL in 96.1 and 95.5 percent of men in the two degarelix groups. On leuprolide, it was none. No extra testosterone-blocking pill is needed at the start.
That advantage comes with two costs. They are easy to find in the data and easy to leave out of a summary. The first is the shot itself. 40 percent of men on degarelix, given under the skin, had reactions where the shot went in. On leuprolide, given into the muscle, it was under 1 percent. For a monthly shot taken for years, that is a real reason people stop. The second is that the hoped-for heart advantage has not been shown. A study called PRONOUNCE was built to test exactly that, in men with prostate cancer who already had clogged arteries. It was stopped after 545 of a planned 900 men. It found 15 major heart events on degarelix and 11 on leuprolide. That gap is too small to mean anything.
The right way to read PRONOUNCE is the one its own authors give. Whether blockers or the older drugs are safer for the heart is still unknown. The study did not show degarelix is worse. It did not show it is better. It was stopped before it could show anything.
How does Degarelix work?
It blocks the GnRH receptor in the pituitary gland directly. That stops the hormones that drive the testes right away, so testosterone falls within days with no first surge. This is the opposite of how leuprolide, goserelin and triptorelin work. Those drugs get their effect by first overworking the same receptor. Degarelix also forms a little store under the skin where it was injected, and seeps out slowly. That explains both why it lasts so long in the body and why so many people react at the shot site.
What have studies in people found about Degarelix?
One large study showing it pushes testosterone down as well as leuprolide, faster and with no flare. And one heart safety study, stopped early, that found no difference in major heart events.
- Main study, 610 men, 12 months: testosterone stayed at castration level in 97.2 and 98.3 percent on degarelix and 96.4 percent on leuprolide. It did just as well.
- Day 3 castration-level testosterone: about 96 percent on degarelix, zero percent on leuprolide. That is the whole difference between the two drug types in one number.
- Reactions where the shot went in: 40 percent against under 1 percent. Urine infections 3 against 9 percent, joint pain 4 against 9 percent, chills 4 against 0 percent.
- PRONOUNCE, 545 men of 900 planned, stopped early: 15 major heart events on degarelix against 11 on leuprolide. That gap is too small to separate from chance.
- Side effects on the label in 10 percent or more: shot site reactions, hot flushes, and rises in liver enzymes.
What this does not tell you: The main study measured testosterone, which is a stand-in, not a health outcome. No study has shown degarelix leads to longer life, fewer broken bones or fewer heart events than the older drugs. In the main study, everyone knew which drug they got. That matters for side effects people report themselves. PRONOUNCE was too small because it failed to sign up enough men, not by plan. So it cannot be read as a no-difference result. And the drug lasts about 53 days in the body. If someone does not handle it well, it stays in them for weeks after the last shot.
The state of the research
PRONOUNCE is the most useful thing on this page, and it is almost always described wrongly.
The idea behind it was fair. Earlier data from watching patients, and a review of past studies, had hinted that blockers might be easier on the heart than the older drugs. So the study signed up men who already had clogged arteries. That is where a difference should be easiest to see. It needed 900 men. It got 545 and was stopped, because men signed up more slowly and fewer heart events happened than expected.
With only 26 heart events in total, the range of possible results runs from a big benefit to a big harm. Citing this study as proof that degarelix has no heart advantage treats missing data as a finding.
These drugs were approved because they push testosterone down. That is a stand-in measure, not a health outcome. They do it reliably. But no study has shown that any one of these hormone-lowering drugs helps men live longer than another. The big modern studies that use triptorelin or degarelix mostly give it to everyone as background treatment while testing something else. That might be when to give radiation, or whether to add chemotherapy. Those studies tell you about the added treatment. They do not rank the hormone drugs against each other.
The evidence, in charts
Fig. 1a · how many people
610people, across 1 study in people cited here
| Study | People | Share |
|---|---|---|
| BJU International 2008 | 610 | 100% |
The whole total is one study of 610. Counts are the number of people each study on this page says it signed up. That includes studies that only watched people and gave nobody the compound. 2 more studies in people give no headcount and are not counted here. Studies still signing people up are left out, and only studies cited on this page are counted.
Fig. 1b · evidence mix
All 3 sources here are studies in people.
- Study in people · done in people3100%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
Sources here come from just two years, 2008 and 2021.
Too few different years on this page to draw a timeline.
Fig. 3 · legal status at a glance
US
Approved
UK
Approved
AU
Approved
CA
Approved
Approved in all four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 5 · what the molecule is
- Kind of compound
- Peptide
- Molecule weight
- About 1632 Da as the free base, per the label. A decapeptide with five D-amino acids.
- Half-life
- About 7.6 weeksVery long, weeks+
- Chain length
- None on file
Half-life as stated on file: About 53 days terminal, driven by slow release from the subcutaneous depot.
No amino acid sequence is on file for Degarelix, so none is drawn rather than guessed from a name.
The studies we cite
- Study in people2008The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer
Degarelix shut testosterone down as well as the older drug and did it far faster. 610 men with prostate cancer, typically in their early seventies, got one of two degarelix schedules or a monthly leuprolide injection. By a year, nearly all men in every group were fully suppressed. The difference showed at day three, when almost every degarelix patient was already suppressed and not one leuprolide patient was. The catch is the injection. Four in ten degarelix patients reacted at the injection site, against almost nobody on leuprolide.
610 men with prostate adenocarcinoma, median age 72, randomised to two degarelix regimens or monthly intramuscular leuprolide. Testosterone at or below 0.5 ng/mL at every monthly measurement from day 28 to day 364 in 97.2, 98.3 and 96.4 percent respectively, meeting non-inferiority. At day 3, testosterone was at or below 0.5 ng/mL in 96.1 and 95.5 percent of degarelix patients and in none on leuprolide. Injection site reactions 40 percent with subcutaneous degarelix versus under 1 percent with intramuscular leuprolide, P below 0.001.
- Study in people2021Cardiovascular Safety of Degarelix Versus Leuprolide in Patients With Prostate Cancer: The Primary Results of the PRONOUNCE Randomized Trial
This trial was meant to settle whether degarelix is kinder to the heart than the older drug, and it stopped before it could. 545 men with prostate cancer and known artery disease were enrolled, out of 900 planned. Over a year, 15 men on degarelix and 11 on leuprolide had a heart attack, stroke or cardiac death. Those counts are far too small to separate the two drugs. The authors say the question is still open. Do not read this as proof that the two are equally safe.
Randomised, open-label, in men with prostate cancer and known atherosclerotic cardiovascular disease. Enrolment stopped early at 545 of a planned 900 patients across 113 sites in 12 countries. Major adverse cardiovascular events at 12 months: 15 (5.5 percent) on degarelix versus 11 (4.1 percent) on leuprolide, hazard ratio 1.28 (95 percent CI 0.59 to 2.79), P equal to 0.53. The authors conclude that the relative cardiovascular safety of GnRH antagonists and agonists remains unresolved.
- Study in people2021A Trial Comparing Cardiovascular Safety of Degarelix Versus Leuprolide in Patients With Advanced Prostate Cancer and Cardiovascular Disease
The registry entry records what the published paper does not make obvious. The trial was terminated. It signed up 545 men when it had planned for 900. This matters, because the paper is routinely quoted as showing degarelix offers no heart advantage. A trial stopped at three fifths of its target cannot show that, or the opposite. The registry record is the receipt.
The registry record for PRONOUNCE. Overall status is TERMINATED, with actual enrolment 545 against a planned 900. Worth citing directly, because the published paper is routinely quoted as evidence that degarelix confers no cardiovascular benefit when the registry entry records a trial that was stopped before it could answer the question either way.
Where to buy Degarelix
Degarelix is an approved medicine. The approved product comes from a pharmacy, with a prescription. The vials below are sold “for research” and are not the approved drug.
No seller we track lists Degarelix yet. We read sellers’ public product lists every week, and this section fills in as soon as one does. Every seller, graded
Common questions
Has Degarelix been tested in people?
Yes. 610 people given it across 2 completed trials cited here, 0 of which found nothing. Degarelix is a hormone blocker approved in 2008 for advanced prostate cancer.
What is the Degarelix dosage?
Approved medicine. No human dose established for unlabelled uses. Labeled amounts sit on the prescribing information. This page records what trials measured, not a personal dose. FDA-approved on 24 December 2008 under NDA 022201, sold as Firmagon, to treat advanced prostate cancer. No boxed warning. Not approved for any use beyond that, including prostate cancer that has not spread, any use in women, or any use in healthy adults.
Is Degarelix FDA-approved?
FDA-approved on 24 December 2008 under NDA 022201, sold as Firmagon, to treat advanced prostate cancer. No boxed warning. Not approved for any use beyond that, including prostate cancer that has not spread, any use in women, or any use in healthy adults.
What is degarelix approved for?
Treating advanced prostate cancer. That is the entire use on the US label. The licences in the UK, Australia and Canada are just as narrow.
Why choose degarelix over leuprolide?
Speed, and no testosterone flare. By day 3, about 96 percent of men on degarelix had testosterone at castration level, against none on leuprolide. So no extra testosterone-blocking pill is needed at the start. Over 12 months the two hold testosterone down equally well. No study has shown a difference in survival.
Does degarelix protect the heart?
That has not been shown. PRONOUNCE tested it head on in men with heart disease. It was stopped after 545 of a planned 900 men. It found 15 heart events on degarelix and 11 on leuprolide. The range of possible results is wide enough to include a real benefit and a real harm. The question is open, not answered.
How bad are the injection site reactions?
Common. 40 percent of men on degarelix in the main study, against under 1 percent on leuprolide shots into the muscle. Pain, redness, swelling and hardening at the site are each listed at 10 percent or more on the label. For a monthly shot taken for years, that is a real reason people stop, not just a cosmetic issue.
How long do the effects last after stopping?
It lasts about 53 days in the body, so it stays in you for weeks to months after the last shot. Testosterone comes back just as slowly.