Ursodiol is not available over the counter. It is a prescription-only medication in the United States, classified as “Rx only” by the FDA. You need a doctor’s prescription to obtain it at a pharmacy, and that requirement applies to all dosage forms and strengths.
Why Ursodiol Requires a Prescription
Ursodiol treats serious liver and gallbladder conditions that need medical diagnosis and ongoing monitoring. Its three main uses are dissolving existing gallstones in people who cannot or do not want surgery, preventing gallstone formation during rapid weight loss, and treating primary biliary cholangitis (an autoimmune liver disease). Each of these conditions requires imaging, blood work, or both before treatment starts, and a doctor needs to confirm that ursodiol is appropriate for the specific situation.
Dosing also varies significantly depending on the condition. For gallstone prevention during weight loss, the typical dose is 300 mg twice a day. For primary biliary cholangitis, the dose is weight-based, usually 13 to 15 mg per kilogram of body weight per day, split into multiple doses. Getting the dose wrong can mean the medication simply doesn’t work. At the same time, doses above a certain threshold don’t increase the drug’s concentration in bile, so more is not better. These are decisions that require a prescriber’s judgment.
Gallstone dissolution is also a slow process that needs follow-up. Stones shrink at a median rate of about 0.7 mm per month, meaning treatment often runs for many months. If stones haven’t responded after six months, or haven’t fully dissolved after two years, the approach typically changes. Without medical oversight, a person could spend months on an ineffective regimen or miss a complication that needs urgent attention.
How Well Ursodiol Works for Gallstones
Success rates depend heavily on stone size. Gallstones smaller than 5 mm dissolve completely in about 70% of patients. For stones under 10 mm, that rate drops to around 49%, and for stones larger than 10 mm, only about 29% fully dissolve. A meta-analysis of all randomized trials on dissolution treatment found an overall success rate of 37%. These numbers explain why ursodiol is typically reserved for people with small, cholesterol-based stones who aren’t good candidates for surgery. Stopping treatment too early can also prevent full dissolution, which is another reason ongoing medical follow-up matters.
What Ursodiol Does in the Body
Ursodiol is a naturally occurring bile acid that makes up a small fraction of the bile your liver produces. When you take it as a medication, it shifts the composition of your bile by reducing the amount of cholesterol secreted into it. Since most gallstones are primarily cholesterol, lowering cholesterol saturation in bile allows existing stones to gradually dissolve and prevents new ones from forming.
At a standard dose of 8 to 10 mg per kilogram per day, ursodiol enriches your bile acid pool by roughly 40%. Beyond that, it also has protective effects on liver cells, which is why it’s used for primary biliary cholangitis, a condition where the immune system slowly damages the bile ducts inside the liver.
Can You Buy It OTC in Other Countries?
Ursodiol (also called ursodeoxycholic acid) is a registered prescription medicine in Australia as well, where it is classified as a regulated medication through the Therapeutic Goods Administration. In Canada and the United Kingdom, it similarly requires a prescription. There is no major market where ursodiol is sold as a standard over-the-counter product. You may encounter supplements marketed as bile acid support or containing small amounts of bile acids, but these are not the same as pharmaceutical-grade ursodiol and are not approved for treating gallstones or liver disease.
How to Get a Prescription
If you think ursodiol could help your situation, the path starts with your primary care doctor or a gastroenterologist. For gallstones, you’ll typically need an ultrasound to confirm the stones are cholesterol-based and to measure their size, since ursodiol does not work on calcified stones. For liver conditions, blood tests assessing liver function will guide both the decision to prescribe and the dosing. Once prescribed, ursodiol is widely available at retail pharmacies and through mail-order services, and generic versions keep the cost lower than many specialty medications.