Zoladex for Breast Cancer: What to Expect, Side Effects, and More

Zoladex (chemical name: goserelin) is used to reduce the risk of early-stage, hormone receptor-positive breast cancer coming back in pre-menopausal women after surgery and other treatments. It is usually prescribed for five to ten years, and is prescribed with an oral anti-estrogen medication as well. Zoladex may also be used alone or in combination with other antiestrogen oral medications for the treatment of stage IV or metastatic breast cancer.

Zoladex also can be used for ovarian suppression to preserve fertility during treatment during chemotherapy for early-stage breast cancer.

See Zoladex prescribing information.

Zoladex is an LHRH (luteinizing hormone-releasing hormone) agent. LHRHs shut down the ovaries and stop them from producing estrogen — estrogen fuels the growth of hormone receptor-positive breast cancer.

Lupron and Trelstar are also LHRHs.

Zoladex is a small implant that is about the size of a grain of rice. Your doctor or nurse will use a needle to inject Zoladex under your skin every 28 days into your lower abdomen. It’s called a “depot injection,” which means the medicine slowly releases into your bloodstream over four weeks. Zoladex can also be given in an every-three-month form, but this is not used as frequently in breast cancer treatment.

Since Zoladex is an implant, the needle used to inject it may be larger than you’re used to. Talk to your care team if you have concerns. 

Like almost all breast cancer medicines, Zoladex can cause side effects, some of them severe.

The most common side effects of Zoladex are:

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  hot flashes

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  loss of libido

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  vaginal dryness

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  irregular periods or loss of period

More rare side effects include edema, nausea and vomiting, fatigue, and changes in bone mineral density. 

You should not take Zoladex if you’re pregnant or breastfeeding. 

Members of our community discuss their experiences with Zoladex in the community forum. Here are some of their comments. Remember, it's essential to talk to your doctor about any side effects you're having and ask about ways to manage them.

“My only side effect is hot flashes from the Zoladex.” —Member_of_the_Club

“I've been on Zoladex for almost seven years. I have no side effects from it. However, Zoladex is a pill that is inserted in your subcutaneous fat with a giant needle, the biggest needle I have ever seen. Fortunately, I don't mind but the nurses keep apologizing for the size of the needle. Bottom line: Zoladex is not for needlephobes.” —elainetherese

“I've had two shots so far and I don't think I've had any side effects yet, except maybe some hot flashes. But that's expected. I haven't needed any preparation, it hurts a little but it's not bad and over quickly.” —parakeetsrule

Read more in our Zoladex discussion forum.

The cost of Zoladex may vary. The price you’ll pay depends on the drug manufacturer, your health insurance provider and plan, where you live, and the pharmacy you use. 

Note: Your insurance company may require you to get prior authorization before covering Zoladex. 

Learn more about financial assistance and medicine cost-lowering tips.