Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Call your doctor at once if you have:
liver problems--nausea, upper stomach pain, itching, tired feeling, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); or
signs of a new infection--sudden weakness or ill feeling, fever, chills, sore throat, mouth sores, skin sores, trouble swallowing.
Common side effects may include:
headache, dizziness;
mild stomach pain or discomfort;
nausea, diarrhea, constipation;
cold symptoms such as stuffy nose, sneezing, sore throat;
hair loss; or
mild itching or rash.
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.
 Ursodiol side effects (more detail)
