Zoladex (goserelin) is a brand-name drug that’s prescribed for conditions including breast and prostate cancer in adults. Zoladex comes as an implant that’s placed under your skin by a healthcare professional. The dosage can vary depending on what condition the drug is prescribed to help treat.

Zoladex is approved by the Food and Drug Administration (FDA) for the following uses:

Zoladex belongs to a drug class called gonadotropin-releasing hormone agonists. Zoladex is not available in a generic version.

Keep reading for specific information about the dosage of Zoladex, including its strengths and how you’ll receive the medication. For a comprehensive look at Zoladex, see this article.

Note: This article describes typical dosages for Zoladex provided by the drug’s manufacturer. However, your doctor will prescribe the Zoladex dosage that’s right for you.

The information below describes Zoladex’s typical dosages and other details about the drug.

Zoladex form

Zoladex comes as an implant that’s placed under your skin by a healthcare professional in their office.

Zoladex strengths

Zoladex comes in two strengths: 3.6 milligrams (mg) and 10.8 mg.

Typical dosages

The following information describes dosages that are commonly prescribed or recommended in adults. Your doctor will determine the best dosage to fit your needs.

Dosage for prostate cancer

Doctors may prescribe Zoladex to treat prostate cancer. The drug is typically prescribed along with flutamide and radiation therapy.

If your doctor prescribes Zoladex for prostate cancer, you’ll receive one 3.6-mg implant once every 28 days for 8 weeks. After 8 weeks, you’ll start radiation therapy while you continue receiving Zoladex. Your doctor may recommend that you continue to receive one 3.6-mg implant once every 28 days, or they may change your dosage to one 10.8-mg implant.

For example, you may receive four 3.6-mg implants. Or you may receive two 3.6-mg implants followed by one 10.8-mg implant.

For more information about your specific dosage, talk with your doctor.

Dosage for palliative treatment of advanced prostate cancer

Doctors may prescribe Zoladex as a palliative treatment for advanced prostate cancer.

If your doctor prescribes Zoladex for this condition, you’ll receive one 3.6-mg implant once every 28 days or one 10.8-mg implant once every 12 weeks.

For more information about your specific dosage, talk with your doctor.

Dosage for palliative treatment of breast cancer

Zoladex is approved to help ease the pain of advanced breast cancer. You’ll receive one 3.6-mg implant once every 28 days for as long as your doctor recommends.

Talk with your doctor if you have questions about your dosage.

Dosage for endometriosis

Zoladex is approved to help treat endometriosis. In this case, you’ll receive one 3.6-mg implant once every 28 days for up to 6 months.

Talk with your doctor if you have questions about your dosage.

Dosage for uterine bleeding

Zoladex is approved to help treat abnormal uterine bleeding. For this use, Zoladex is given before a procedure known as an endometrial ablation. You’ll receive one 3.6-mg implant. In some cases, your doctor may recommend a second 3.6-mg implant placed 4 weeks after the first.

If you receive one 3.6-mg implant, your surgery will take place 4 weeks later. If you receive two 3.6-mg implants, your surgery will be 2–4 weeks after the second implant is given.

Talk with your doctor if you have questions about your dosage.

Long-term treatment

Depending on the condition, Zoladex may be prescribed long term or short term.

Talk with your doctor if you have questions about how long you can expect to receive treatment with Zoladex.

The Zoladex dosage your doctor prescribes will depend on several factors. These include:

  • how your body responds to Zoladex
  • the type and severity of the condition you’re prescribed Zoladex to treat

Other medical conditions you have can also affect your Zoladex dosage.

Zoladex comes as a solid implant in a syringe. A healthcare professional will administer Zoladex in their office.

First, the healthcare professional will clean an area of your abdomen with an alcohol swab. Then, they’ll pinch your skin slightly and insert the needle of the syringe into it to administer the implant. The implant is about 1 centimeter (less than 0.5 inches) long. It will stay under your skin and slowly dissolve over time.

If you have questions about what to expect with your Zoladex implant, talk with your doctor or pharmacist.

If you miss your appointment to receive your Zoladex implant, call your doctor’s office as soon as possible to reschedule. They’ll adjust your dosing schedule as needed.

If you need help remembering your appointments, try setting an alarm or downloading a reminder app on your phone.

Below are some frequently asked questions about Zoladex.

Is the dosage of Zoladex similar to the dosage of Lupron Depot?

No, it isn’t. Zoladex and Lupron Depot may be prescribed for similar uses. However, Lupron Depot is given as a subcutaneous injection, while Zoladex is a solid implant.

The dose in mg and how often you receive each drug differs because they have different active ingredients. 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 Zoladex to start working?

Zoladex starts to work after your first dose. However, it may take a couple of weeks to feel the full effect of the drug. Your doctor will monitor you during treatment to check whether the drug is working to treat your condition.

Talk with your doctor if you have questions about what to expect with Zoladex treatment.

The dosages in this article are typical dosages provided by the drug’s manufacturer. If your doctor recommends Zoladex for you, they will prescribe the dosage that’s right for you.

If you have questions about the dosage of Zoladex that’s best for you, talk with your doctor.

Besides learning about dosage, you may want other information about Zoladex. These additional articles might be helpful:

Disclaimer: Medical News Today 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.