Nausea, bloating, headache, changes in appetite, weight gain, tiredness, swelling, acne, hot flashes, breast tenderness, or irritation/pain at the injection site may occur. Vaginal bleeding between periods (spotting) or missed/irregular periods may occur, especially during the first few months of use. If any of these effects last or get worse, tell your doctor or pharmacist promptly. Your periods may stop completely after you have been using this medication for about a year. If this occurs, your periods will normally return after you stop using this medication. If you miss a period and have missed an injection, or if more than 14 weeks pass between injections and you think you might be pregnant, contact your doctor for a pregnancy test.
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 you have any serious side effects, including: nausea/vomiting that doesn't stop, mental/mood changes (such as new/worsening depression), changes in sexual interest/ability, swelling of the ankles/feet, bone pain, unusual changes in vaginal bleeding (such as continuous spotting, sudden heavy bleeding), severe stomach/abdominal/pelvic pain, unusual weakness/tiredness, dark urine, yellowing skin/eyes, seizure.
This medication may increase your risk of breast cancer. Tell your doctor right away if you have symptoms such as a lump in the breast, nipple discharge. Ask your doctor for more details.
Rarely, people using this medication have had very serious (possibly fatal) problems from blood clots (such as heart attack, stroke, blood clots in the lungs, legs, or eyes). Get medical help right away if you have: shortness of breath/rapid breathing, chest/jaw/left arm pain, unusual sweating, confusion, sudden dizziness/fainting, pain/swelling/warmth in the groin/calf, sudden/severe headaches, trouble speaking, weakness on one side of the body, sudden vision changes.
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 MedWatch: The FDA Safety Information and Adverse Event Reporting Program.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.