Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
chest pain; or
uneven heartbeats.
Common side effects may include:
loss of appetite;
diarrhea, constipation, upset stomach, belching;
back pain; or
dry mouth, altered sense of taste.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
 Lovaza side effects (more detail)
