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Trade/other name(s): Zoladex, Zoladex 3-month

Why would this drug be used?

Goserelin is used to treat prostate and breast cancers, and is sometimes used for other conditions.

How does this drug work?

Goserelin is a member of the general group of drugs known as hormones or hormone antagonists. It is a man-made version of the body's luteinizing-hormone-releasing hormone (LHRH). This drug stops the release of testosterone from the testicles in men and the release of estrogen from the ovaries in women. This slows or stops the growth of cells (including cancer cells) that depend on these hormones. If the medicine is stopped, hormone levels are expected to return to normal.

Before taking this medicine

Tell your doctor…

  • If you are allergic to anything, including medicines, dyes, additives, or foods.
  • If you have any medical conditions such as kidney disease, liver disease (including hepatitis), congestive heart failure, gout, or infections. These conditions may require that your medicine dose, regimen, or timing be changed.
  • If you have ever had diabetes, heart disease, high blood pressure, high cholesterol, heart attack, or stroke. Also tell your doctor if you have ever smoked. Your doctor may watch you more closely for heart and blood vessel problems while you take this drug.
  • If you have ever been diagnosed with heart problems, especially long QT syndrome, an abnormal heart rhythm, congestive heart failure, or if you have been told you have low blood levels of potassium, calcium, or magnesium (which can affect the heart). In men, this drug can affect the rhythm of the heart, which might lead to irregular heartbeats and can even lead to death.
  • If you or others in your family have weakened bones (osteoporosis), if you have ever been a heavy user of alcohol, or if you have taken steroids or medicines to prevent seizures, which can cause bone loss. Goserelin can speed up loss of bone minerals and your doctor may need to watch for this.
  • If you have trouble passing your urine due to enlarged prostate or other blockage.
  • If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug may harm the baby or cause birth defects if it is taken at the time of conception or during pregnancy. (See “Precautions” section.)
  • If you are breast-feeding. This drug can interfere with milk production. Also, it is not known whether this drug passes into breast milk. If it does, it could harm the baby.
  • If you want to have children in the next few months or a year. This drug may reduce fertility while you are on it and for some time after.
  • About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

Because goserelin can affect the rhythm of the heart, be sure your doctor is aware of any drugs you take that affect heart rhythm. Examples of these drugs include:

  • Amiodorone (Cordarone, Pacerone)
  • Disopyramide (Norpace)
  • Dofetilide (Tikosyn)
  • Flecainide (Rhythmol)
  • Ibutilide (Corvert)
  • Mexiletine (Mexitil)
  • Moricizine (Ethmozine)
  • Procainamide (Procan, Pronestyl)
  • Propafenone (Tambocor)
  • Quinidine (Quinidex, Cardioquin)
  • Tocainide (Tonocard)

Beta blocker drugs slow the heart rate and can worsen effects on the heart. This class includes drugs like acebutolol (Sectral), atenolol (Tenormin), bisoprolol (Zebeta), esmolol (Brevibloc), metoprolol (Lopressor, Lopressor LA, Toprol XL), nadolol (Corgard), propranolol (Inderal), sotalol (Betapace), and timolol (Blocadren).

Clonidine (Catapres), digoxin (Lanoxin, Cardoxin, Digitek), and the calcium channel blockers diltiazem (Cardizem) and verapamil (Covera, Calan, Verelan) can also slow the heart and might cause problems while you are on goserelin.

These drugs affect the rhythm of the heart in the same way as goserelin and so can also increase your risk of abnormal heart rhythm if you take them during the same times you are on goserelin.

  • Anti-psychotic drugs such as thioridazine (Mellaril), haloperidol (Haldol), mesoridazine (Serentil)
  • Antidepressants such as venlafaxine (Effexor) and amitriptyline (Elavil)
  • Certain antibiotics (e.g., erythromycin, clarithromycin, levofloxacin, ofloxacin, moxifloxacin, sparfloxacin, pentamidine)
  • Nausea medicines such as ondansetron (Zofran), dolasetron (Anzemet), granisetron (Kytril), droperidol (Inapsine), promethazine (Phenergan), and chlorpromazine (Thorazine)

This is not a complete list. Other drugs that can slow the heart rate or prolong the QT interval of the heart can increase the increase the danger of an abnormal rhythm. Check with your doctor or pharmacist to find out if other drugs you’re taking have this effect.

This drug lowers estrogen levels in women. Birth control pills (and other drugs containing estrogen) can lower the effectiveness of this drug.

Check with your doctor, nurse, or pharmacist about other medicines, vitamins, herbs, and supplements, and whether alcohol can cause problems with this medicine.

Interactions with foods

No serious interactions with food are known at this time. Check with your doctor, nurse, or pharmacist about whether foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Goserelin is injected under the skin once a month. The medicine is slowly released over 1 month. There is also a dose that lasts for about 12 weeks, which is injected once every 3 months.


In men

Goserelin may briefly increase testosterone levels when the drug is first started. This causes the symptoms of prostate cancer to get worse for about a week and is called a disease or tumor “flare.” To prevent this, doctors can give drugs that block testosterone for the first week of treatment. These symptoms usually improve after a week or two, but sometimes extra treatment is needed.

  • The prostate gland may enlarge, and you may have blood in your urine, painful urination, or trouble passing urine. Call your doctor if you have these symptoms. If the flow of urine is blocked completely, this can lead to kidney failure.
  • Bone pain may also worsen. Call your doctor or nurse right away if your pain medicine is not stopping the pain during this time. Your doctor should help you get the right dose or drug for the time that the pain has increased.
  • If prostate cancer has spread to the bones of the spine, the flare can cause the cancer to press on the spinal cord and cause spinal cord compression. Early symptoms include numbness in the legs or feet, trouble urinating or moving your bowels, back pain, and weakness in the legs. If left untreated it can lead to paralysis (loss of movement). Call your doctor right away if you have any of these symptoms.
  • Tell your doctor if you have any of the above flare symptoms that last longer than 2 weeks.

Your doctor will check your blood during treatment to see the drugs effect on your cancer and look for side effects. It’s important to keep all your appointments, even those just for blood tests.

This drug may raise your blood sugar (glucose) levels or even lead to diabetes. Tell your doctor if you have ever had diabetes or high blood sugar, or if you have symptoms that can be caused by high blood sugar, such as feeling thirsty all the time or having to urinate more often than normal. Your doctor may check your blood sugar levels while you are taking this drug.

Patients on goserelin have an increased risk of heart attack and stroke. Call your doctor right away if you have pain in the chest, neck, pain, jaw or arm, shortness of breath, headache, numbness or weakness on one side of your body, or trouble talking,

Androgen deprivation therapy (such as goserelin) can cause a change in heart rhythm called prolonged QT interval. Tell your doctor if you have ever been diagnosed with any type of heart disease, especially an abnormal heart rhythm or long QT syndrome. Your doctor may need to test your heart rhythm with an EKG and test your blood levels of certain minerals that could affect heart rhythm during treatment. Tell your doctor or nurse right away if you notice a fast or irregular heartbeat, very slow heartbeat, lightheadedness, dizziness, fainting, or shortness of breath to your doctor right away. Tell your doctor if you start to take or have any changes in heart or blood pressure medicines.

Rarely, goserelin can cause the calcium level in the blood to increase in men who have prostate cancer that has spread to the bones. Call your doctor for treatment if you notice nausea, vomiting, thirst, weakness, and confusion.

Call your doctor right away if you develop skin welts, itching, swelling in the face, mouth, or throat, or other signs of an allergic reaction.

In women

Although you may have some vaginal bleeding at first, menstrual periods usually stop while you are on this drug. If you keep having periods, there may be a problem, and so you should talk to your doctor.

Although menstrual periods usually stop, it does not mean you cannot get pregnant. Taking this drug at the time of conception or during pregnancy can increase the risk of miscarriage or other harm to the fetus. Women who are taking this drug should use effective birth control during treatment. Ask your doctor what kinds of birth control can be used with this medicine. If you get pregnant while taking this drug, tell your doctor right away so that the drug can be stopped.

Rarely, goserelin can cause the calcium level in the blood to increase in women who have breast cancer that has spread to the bones. Call your doctor for treatment if you notice nausea, vomiting, thirst, weakness, and confusion.

By lowering estrogen levels, this drug can affect emotions and worsen problems with depression. Let your doctor know if you have a depressed mood, crying spells, trouble sleeping, loss of appetite, or suicidal thoughts.

Call your doctor right away if you develop skin welts, itching, swelling in the face, mouth, or throat, or other signs of an allergic reaction.

Possible side effects

You will probably not have most of the following side effects, but if you have any talk to your doctor or nurse. They can help you understand the side effects and cope with them. This drug can have different side effects in men and women.


  • Hot flashes and sweats
  • Decrease in sexual desire
  • Menstrual periods stopping or becoming much lighter.* In most women, periods resume within a few months after the drug is stopped.
  • Vaginal dryness or irritation (in women)
  • Depression or feeling emotional (in women)*
  • Skin problems, including acne or dry skin (in women)
  • Breasts becoming smaller or less full (in women)
  • Swelling in the hands or feet (more often seen in women)

Less common

  • “Flare” reaction at the start of treatment for prostate cancer (in men)*
  • Decreased sexual ability in men (impotence or erectile dysfunction)
  • Problems passing urine, including feeling the urgent need to pass urine, burning when passing urine, and blood in the urine
  • Pain during sexual intercourse (in women)
  • Increase in sexual desire (in women)
  • Increased face or body hair (in women)
  • Pain, including pain in the belly, back, muscles, bones, and joints
  • Feeling weak or low energy
  • Nausea
  • Feeling dizzy
  • Severe bone thinning or weakness (osteoporosis), which increases the risk of having a bone break


  • Breast tenderness or swelling (in men)
  • Increased weight
  • Constipation
  • Headache
  • Increased blood sugar (including diabetes)*
  • Increased levels of calcium in the blood (in people being treated for cancer)*
  • Kidney damage
  • Blood vessel disease (heart attack or stroke)*
  • Allergic reactions*
  • Problems with heart rhythm, which may be serious*
  • Pressure or bleeding in the pituitary gland, causing vomiting, headache, changes in vision, confusion, collapse, or other serious symptoms (this can occur in people who had a tumor in the pituitary, but didn’t know it before treatment)
  • Birth defects and other fetal harm if used during pregnancy*
  • Death due to diabetes, heart problems, stroke, or some other cause

*See "Precautions" section for more detailed information.

There are some other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 1989.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.

Last Medical Review: 09/17/2014
Last Revised: 10/14/2014