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[Pharmacology](https://durgical.com/en/pharmacology/) · Class

# Bile acids

Bile acids given as medicines to change the make-up of bile: they dissolve some cholesterol gallstones and protect the liver in cholestatic disease.

Updated 2026-11-01

## What they are

Natural or modified bile acids used in biliary disease. Ursodeoxycholic acid dissolves small cholesterol gallstones and treats primary biliary cholangitis; obeticholic acid (an FXR agonist) and chenodeoxycholic acid belong to the same ATC group.

## Mechanism of action

Ursodeoxycholic acid lowers cholesterol secretion into bile and helps dissolve cholesterol in micelles and liquid crystals, so bile stops precipitating stones. It also replaces more toxic bile acids in the bile acid pool, which helps in cholestatic liver disease.

Target: Bile composition and the bile acid pool

## Key points

- Only radiolucent, non-calcified cholesterol stones dissolve; calcified or pigment stones do not.
- Approved treatment for primary biliary cholangitis, an autoimmune cholestatic liver disease.
- Prevents gallstones during rapid weight loss.
- Bile acid sequestrants and aluminium antacids bind it and reduce its effect.

## Drugs in this class

- [**Ursodeoxycholic acid** A natural bile acid that makes bile dissolve cholesterol. It treats primary biliary cholangitis and can slowly… Bile composition (cholesterol saturation and bile acid pool)](https://durgical.com/en/pharmacology/ursodeoxycholic-acid/)

## Others in the class

- Chenodeoxycholic acid
- Obeticholic acid
- Cholic acid

## Test yourself

Think of the answer, then tap the question to see it.

## Which gallstones can ursodeoxycholic acid dissolve?

Radiolucent, non-calcified cholesterol stones; calcified, radiopaque or pigment stones do not dissolve.

## Which autoimmune liver disease is treated with ursodeoxycholic acid?

Primary biliary cholangitis.

## Why do cholestyramine and aluminium antacids reduce its effect?

They bind bile acids in the gut and lower their absorption.

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Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=A05AA) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [DailyMed - URSODIOL capsule](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a061bb07-a85d-4b08-877f-ce02156f0de7) (DailyMed (U.S. National Library of Medicine), 2023); [DailyMed - URSODIOL tablet](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=a3c98080-0a4d-4a93-8dcb-02ab8533050b) (DailyMed (U.S. National Library of Medicine), 2026); [Ursodiol: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a699047.html) (MedlinePlus (U.S. National Library of Medicine), 2023).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/classes/bile-acids/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/classes/bile-acids/