Ursodiol: what it treats, how to take it, side effects
Last updated September 3, 2026.
Ursodiol is a bile acid - it decreases cholesterol production and dissolves cholesterol in bile, preventing stones and diluting the toxic bile acids that accumulate in liver disease. You may know it as Actigall. The slow medicine: it works over months, and it is honest about it.
What does it treat?
Three jobs: dissolving gallstones in people who do not want surgery or cannot have it; preventing gallstones in people losing weight very quickly; and treating primary biliary cholangitis (PBC), an autoimmune liver disease.
How do you take it?
Capsule or tablet, schedule by use: gallstone dissolution usually two or three times daily; prevention during rapid weight loss, twice daily; PBC, 2 or 4 times daily with food. Breaking a scored tablet: snap it with thumbs by the score, swallow with water without chewing - it is bitter - and store the other half separately, used within 28 days. The patience clause, verbatim from the evidence: months to work, up to 2 years for stone dissolution, some stones never fully dissolve, and half of dissolved stones can return within 5 years. Continue even when you feel well; do not stop without your doctor. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: generally well tolerated - the gut effects (indigestion, nausea, diarrhea or constipation) and headache are the usual reports.
- Serious - call your doctor immediately or get emergency care: persistent stomach pain, nausea, vomiting, or diarrhea; and the allergic set - hives, rash, itching, swelling of face, eyes, mouth, throat, tongue, lips, hands, feet, ankles, or lower legs, or trouble breathing or swallowing.
Who should not take it?
Flag bile duct blockage, pancreatitis, and liver disease beyond the treated one. Antacids with aluminum and the bile-acid resins (cholestyramine) can bind it - spacing matters; tell your doctor and pharmacist everything you take. If you become pregnant, call your doctor.
When is it an emergency?
Throat swelling or trouble breathing is a 911 call. Severe right-upper-abdomen pain with fever is urgent care - that is a gallbladder problem declaring itself, not a drug effect to wait out. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
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Common questions
How long does ursodiol take to dissolve gallstones?
Months, honestly counted: MedlinePlus says up to 2 years for dissolution, the medication must be taken the whole time, some stones never fully dissolve, and stones return within 5 years in up to half of successful cases. That is why patient selection matters - it suits small cholesterol stones in people avoiding or unable to have surgery. The ultrasounds along the way are how your team decides whether the slow road is working.
Why take a pill for years when surgery exists?
Because surgery is not free: anesthesia risk, recovery, and the cases where an operation is genuinely inadvisable. Ursodiol trades months of pills for avoiding the OR - the right trade for the right stone and the right patient, and the wrong one for a large stone or a scarred gallbladder. The selection conversation with your doctor is where the honest comparison happens.
Why is ursodiol used for PBC - a liver disease - too?
Different job, same molecule: in primary biliary cholangitis, toxic bile acids pile up in the liver and damage it; ursodiol displaces and dilutes them, slowing the disease. For PBC it is long-term therapy with liver tests on schedule - not stone dissolution at all. Two uses, two timelines, two monitoring plans - make sure you know which one you are on.
Why did my doctor ask about my antacids and other medications?
Aluminum-containing antacids and bile-acid resins like cholestyramine can bind ursodiol and keep it from absorbing - spacing matters. The rule generalizes: everything you take goes on the list for the pharmacist check. It is a gentle drug with few interactions, which makes the few it has easy to forget.
What are the real side effects?
Mostly none - it is one of the gentler prescriptions, and stomach upset, indigestion, and diarrhea or constipation are the usual reports. The stop-and-call set is the allergic one: hives, rash, itching, swelling of face, lips, tongue, or throat, trouble breathing or swallowing. And the disease's own red flag - severe belly pain with fever - is an emergency regardless of the drug.
What happens if I miss a dose of ursodiol?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. Bile-acid therapy works on steady months of exposure; a missed dose is invisible to the outcome, while a doubled dose just buys stomach upset. The twice-daily anchor with meals is the habit that keeps the long game running.