Mild burning/pain/bruising at the injection site, hot flashes (flushing), increased sweating, night sweats, tiredness, headache, upset stomach, breast changes, acne, joint/muscle aches, trouble sleeping, reduced sexual interest, vaginal discomfort/dryness, vaginal bleeding, swelling of the ankles/feet, increased urination at night, or dizziness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Rarely in men, shrinking of the testicles, breast tenderness/swelling, and reduced sexual interest/ability may also occur as a result of lowered testosterone levels. Talk to your doctor if these effects occur.
In girls, when this medication is used regularly, it is expected that the menstrual period will stop or decrease to light bleeding/spotting during the first 2 months. Tell the doctor promptly if regular periods continue after 2 months of treatment with leuprolide.
Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
Tell your doctor right away if any of these serious side effects occur: new/worsening bone pain (in adults), easily broken bones (in adults), increased thirst/urination (in adults), mental/mood changes (such as depression, thoughts of suicide, mood swings, aggression).
In adults, this medication may rarely cause heart problems and stroke. Get medical help right away if any of these very serious side effects occur: symptoms of a heart attack (such as chest/jaw/left arm pain, shortness of breath, unusual sweating), signs of a stroke (such as weakness on one side of the body, trouble speaking, sudden vision changes, confusion), fast/irregular heartbeat, severe dizziness, fainting.
Get medical help right away if any of these very serious side effects occur: seizures.
Rarely, a very serious problem with your pituitary gland (pituitary apoplexy) may occur, usually in the first hour to 2 weeks after the first injection. Get medical help right away if any of these very serious side effects occur: sudden severe headache, sudden severe mental/mood changes (such as severe confusion, difficulty concentrating), vision changes, severe vomiting, fainting.
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.