Goserelin is a medication that mimics the actions of gonadotropin-releasing hormone (GnRH or LHRH), a hormone that affects the release of sex hormones such as testosterone and estrogen. Goserelin, in its long-acting form, is used to treat prostate cancer, breast cancer, and endometriosis (a painful condition caused by growth of extra tissue inside or outside the uterus).

Goserelin works by suppressing the production of testosterone and estrogen.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are receiving this medication, speak to your doctor. Do not stop receiving this medication without consulting your doctor.

The usual dose of long-acting goserelin is 10.8 mg injected under the skin on the abdomen every 12 to 13 weeks. The injection is usually given by a health care professional.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are receiving the medication without consulting your doctor.

It is important this medication be given exactly as recommended by your doctor. If you miss an appointment to receive this medication, contact your doctor as soon as possible to reschedule your appointment.

This medication is stored at room temperature and should be protected from light and moisture.

Each depot is supplied as a cylindrical rod containing goserelin acetate equivalent to 10.8 mg of goserelin. This depot is available as a sterile ready-to-use syringe with a 14-gauge needle for a single subcutaneous injection. Nonmedicinal ingredients: lactide-glycolide copolymer.

Do not use goserelin if you:

• are allergic to goserelin or any of the ingredients of the medication
• are breast-feeding
• are pregnant
• have undiagnosed abnormal vaginal bleeding

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• abdominal pain
• acne
• breast tenderness
• change in breast size
• decreased sexual interest
• hair loss
• headache
• "hot flashes" (sudden sweating and feeling of warmth)
• joint pain
• nausea
• pain or redness at the place of injection
• pelvic pain
• sexual difficulties
• skin rash, redness, or itching
• stopping of menstrual periods
• thirst
• tingling in fingers and toes
• trouble urinating
• vaginal burning, dryness, or itching
• vomiting
• weight gain

Although most of these side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blood pressure changes
• bone pain
• bone thinning
• hallucinations (seeing or hearing things that aren't there)

• headache
• increased tumour pain
• joint pain
• mood changes, including anxiety or depression
• severe bleeding due to injection site injury (e.g., bleeding under the skin, bruising, swelling at injection site, dizziness, low blood pressure)
• signs of depression (e.g., poor concentration, changes in weight, changes in sleep, decreased interest in activities, thoughts of suicide)
• symptoms of heart failure (e.g., swelling of the feet or legs, shortness of breath, and fatigue)

• symptoms of pituitary tumours (e.g., headache, vomiting, loss of eyesight, loss of consciousness)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• pain, redness, swelling, and feeling of warmth in the calf
• severe allergic reaction (e.g., hives; difficulty breathing; wheezing; or swelling of the eyes, mouth, or lips)
• signs of bleeding in the stomach (e.g., bloody, black, or  tarry stools, spitting up of blood, vomiting blood or material that looks like coffee grounds)
• symptoms of a heart attack (e.g., sudden pain or discomfort in the chest, neck, jaw, shoulder, arms, or back; shortness of breath; nausea or vomiting; cool clammy skin; and anxiety or denial)
• symptoms of spinal cord compression (e.g., numbness or tingling sensations, loss of movement or weakness in arms or legs)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Anemia: Reduced testosterone levels contribute to low levels of red blood cells. If you experience symptoms of reduced red blood cell count (anemia) such as shortness of breath, feeling unusually tired, or pale skin, contact your doctor as soon as possible.

Your doctor will do blood tests regularly to monitor the number of specific types of blood cells, including red blood cells, in your blood.

Depression: Changed levels of hormones in the body have been known to cause mood swings and symptoms of depression. If you have depression or a history of depression, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

If you experience symptoms of depression such as poor concentration, changes in weight, changes in sleep, or decreased interest in activities, or notice them in a family member who is taking this medication, contact your doctor as soon as possible.

Diabetes: Goserelin may cause a loss of blood glucose control, and glucose tolerance may change. People with diabetes may find it necessary to monitor their blood sugar more frequently while using this medication.

If you have diabetes or are at risk for developing diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Fertility: When estrogen production is stopped, people stop ovulating. As a result of stopping the production of sex hormones, menstrual bleeds will also stop. Once goserelin has been discontinued, normal ovulation and menstrual bleeding should return in approximately 12 weeks. If you are planning to become pregnant, wait until you have had at least one normal menstrual period. On rare occasions, some people may enter menopause early and menstruation does not return after stopping treatment.

Heart problems: If you have heart disease or another heart problem such as heart failure or an abnormal heart rhythm, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

There may be an increased risk of heart-related events (e.g., heart attacks, stroke, heart-related death) in men being treated for prostate cancer with GnRH medications. Before you start treatment, tell your doctor if you have diabetes, heart disease, had a previous heart attack or stroke, or have cardiovascular risk factors (e.g., high blood pressure, smoking, or cholesterol). If you have any of these conditions, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Osteoporosis: Goserelin can cause bones to lose thickness. Your doctor will monitor you for this while you are using this medication. If you have osteoporosis or are at risk for it (e.g., have been smoking or drinking excessive amounts of alcohol for a long time, have a family history of osteoporosis, or are taking medications such as prednisone or anti-seizure medications), discuss with your doctor how this medication may affect your medical condition and whether any special monitoring is needed.

Pituitary tumour: Although very rare, pituitary gland tumours may develop, bleed, or collapse with goserelin treatment. If you experience severe headaches, vomiting, loss of eyesight, or unconsciousness, get immediate medical attention.

Short-term worsening of medical condition: For some people, their medical condition may temporarily worsen during the first month of treatment with goserelin. If your medical condition appears to worsen, contact your doctor.

Spine problems: When people with cancer that has spread to their spine receive goserelin, spinal cord compression can occur. If you develop severe pain, numbness or weakness of the arms or legs, or difficulty urinating, contact your doctor immediately.

Pregnancy: Goserelin should not be used during pregnancy. A nonhormonal method of birth control (e.g., condom, diaphragm) should be used during treatment. If you become pregnant while using this medication, stop receiving goserelin and contact your doctor.

Breast-feeding: It is not known if goserelin passes into breast milk. People should not breast-feed while receiving goserelin treatment due to risk of harm to the breast-feeding infant.

Children: The safety and effectiveness of using the medication have not been established for children.

For a full list of interactions, use the Drug Interaction Checker available on the Drugs.com website.

If you are taking other medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.