Injection site reactions (pain/swelling/redness), diarrhea, upset stomach, nausea, or vomiting may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.
Flu-like symptoms such as headache, tiredness, fever, chills, and muscle aches may occur, especially when you first start this medication. These symptoms usually last about 1 day after the injection and improve or go away after a few months of continued use. You can reduce these side effects by injecting this medicine at bedtime and using a fever reducer/pain reliever such as acetaminophen before or after each dose. Consult your doctor or pharmacist for more information.
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: lightheadedness, fainting, mental/mood changes (such as confusion, depression), shaking (tremors), trouble walking, slow/fast/irregular heartbeat, shortness of breath, swelling of the ankles/feet, increasing tiredness, joint pain, butterfly-shaped rash on the face, easy bleeding/bruising, signs of infection (such as sore throat that doesn't go away, fever), signs of liver problems (such as nausea/vomiting that doesn't stop, stomach/abdominal pain, dark urine, yellowing eyes/skin), black/tarry stools, signs of kidney problems (such as change in the amount of urine).
Get medical help right away if you have any very serious side effects, including: chest/jaw/left arm pain, weakness on one side of the body, trouble speaking, sudden vision changes, seizures, pain/redness/swelling of the arms/legs, calf pain/swelling that is warm to the touch, coughing up blood.
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.