Firmagon (degarelix) is a prescription drug used to treat prostate cancer that’s spread to other organs. The drug is given as an injection under your skin, typically every 28 days.
Firmagon is used to treat advanced prostate cancer in adults.
The active ingredient in Firmagon is degarelix. (An active ingredient is what makes a drug work.) Firmagon belongs to a group of drugs called gonadotropin-releasing hormone (GnRH) receptor antagonists.
This article describes the dosages of Firmagon, as well as its strengths and how to take it. To learn more about Firmagon, see this in-depth article.
The table below highlights the basics of Firmagon’s dosage. All doses are listed in milligrams (mg).
| starting dose | 240 mg |
| maintenance dosage | 80 mg every 28 days |
Keep reading for more details about Firmagon’s dosage.
What is Firmagon’s form?
Firmagon comes as a powder in vials. A healthcare professional will mix the powder with sterile water to make a liquid solution that’s injected under your skin.
What strengths does Firmagon come in?
Firmagon comes in two strengths: 240 mg and 80 mg.
For the 240-mg starting dose, you’ll receive two injections of 120 mg each. The 80-mg strength is given as a single injection.
What’s the usual dosage of Firmagon?
The information below describes the dosage that’s commonly used or recommended. But your doctor will determine the best dosage to meet your needs.
Dosage for prostate cancer
The typical Firmagon dosage for adults with prostate cancer that’s spread to other organs consists of a starting dose and an ongoing maintenance dose.
A starting dose is the first dose you’ll receive when your doctor prescribes Firmagon. The typical starting dose is 240 mg given as two injections under your skin at the same appointment.
Your first maintenance dose will be given 28 days after your starting dose. The maintenance dose of 80 mg is then administered every 28 days via a single injection.
Is Firmagon used long term?
Yes, Firmagon is usually a long-term treatment. If you and your doctor determine that it’s safe and effective for your condition, you’ll likely receive it long term.
Dosage adjustments
Firmagon may cause changes to your heart’s rhythm, especially if:
- you have long QT syndrome or heart failure
- you take certain medications that may lengthen the QT interval, such as:
You could also be at risk if levels of certain electrolytes in your blood (sodium, potassium, calcium, magnesium) are higher or lower than usual. Your doctor may periodically check your heart rhythm with an electrocardiogram (EKG). They may also order tests to check your blood levels of certain electrolytes.
If you have moderate to severe kidney problems, your doctor may prescribe Firmagon more cautiously. That’s because a portion of the drug is processed through your kidneys.
If you have liver problems (especially severe ones), your body may only be able to use a portion of each Firmagon dose. To make sure Firmagon is working, your doctor may recommend checking your testosterone levels more frequently. If Firmagon is working, your testosterone levels will decrease, ideally to 50 nanograms/deciliter (ng/dL) or less.
The dosage of Firmagon you’re prescribed may depend on several factors. These include:
- the type and severity of the condition the drug is being used to treat
- your age
- other conditions you may have (see the “Dosage adjustments” section just above)
Firmagon comes as a powder in a vial. A small amount of sterile water is mixed with this powder to create a liquid solution. The solution is given as an injection under your skin by a healthcare professional in a doctor’s office or clinic.
The healthcare professional will inject the dose into your abdomen. Be sure not to scratch or rub the area after the injection. Your dose will be given in a different area of your abdomen each time. Make sure the injection isn’t given in a place where skin is exposed to pressure, such as near your waistband.
If you miss an appointment to receive a dose of Firmagon, call your doctor’s office as soon as possible to reschedule. If you need help remembering your appointments, try downloading a reminder app on your phone.
Below are answers to some commonly asked questions about Firmagon’s dosage.
Is Firmagon’s dosage similar to dosages of Lupron or Zoladex?
Firmagon (degarelix), Lupron Depot (leuprolide acetate), and Zoladex (goserelin) are injections used to treat prostate cancer that’s spread to other organs. But how, where, and when they’re administered can differ.
Firmagon and Zoladex are given as injections under your skin. Lupron Depot is given as an injection into a muscle.
Firmagon and Zoladex are injected into your abdomen. Lupron Depot may be injected into your buttocks, thighs, or shoulders.
Firmagon requires a higher (starting) dose the first time you receive it. Lupron Depot and Zoladex usually don’t require a starting dose.
Firmagon is given every 28 days. Zoladex may also be given every 28 days, but can also be given every 12 weeks, depending on the dosage you’re prescribed. Similarly, Lupron Depot may be given every 4, 12, 16, or 24 weeks, depending on your dosage.
The dose in milligrams (mg) differs for each drug. Your doctor will prescribe the drug and the dosage that’s right for you.
To learn more about how these drugs compare, talk with your doctor.
How long does it take for Firmagon to start working?
Firmagon reduces testosterone levels in your body that make prostate cancer cells grow. A recommended testosterone level to help slow or stop cancer cell growth is 50 nanograms/deciliter (ng/dL) or less. This level is also referred to as medical castration.
Firmagon starts to work right after you receive your first dose. In fact, 52% of people achieved a testosterone level of 50 ng/dL or less within 1 day based on a study. And 99% of people achieved this testosterone level within 14 days of receiving a Firmagon dose.
Your doctor will monitor you during treatment to check whether the drug is working to treat your condition. Talk with them if you have other questions about what to expect with Firmagon.
The sections above describe the usual dosage provided by the manufacturer of Firmagon. If your doctor recommends this drug, they’ll prescribe the dosage that’s right for you. Talk with them if you have questions or concerns about your current dosage. Examples of questions you may want to ask include:
- If I experience side effects, can I receive Firmagon less often than every 28 days?
- Can you teach me how to inject Firmagon on my own at home?
- Can I receive Firmagon injections somewhere other than my abdomen?
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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.