Lactulose

Osmotic laxative
ALSO SOLD WITHOUT PRESCRIPTION

Lactulose is a osmotic laxative found in 1 medicine sold in India, such as Duphalac. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.

What it is used for

Draws water into the gut to soften stools; also used in liver disease.

How it works

A sugar the body cannot absorb. It draws water into the bowel to soften stools, and in liver disease it reduces ammonia absorbed from the gut.

How to take it

Usually 15 ml twice a day for constipation; it can take 2 to 3 days to work. Liver doses are higher and set by the doctor.

Common side effects

  • Wind
  • Bloating
  • Stomach cramps
  • Diarrhoea at high doses

Get medical help straight away if

  • Severe diarrhoea with dizziness
  • Confusion in people with liver disease

Be careful

Can cause gas and bloating at first.

Other medicines and interactions

No important interactions.

Pregnancy and breastfeeding

Safe in pregnancy and breastfeeding.

Brands of Lactulose (1)

Duphalac

Common questions

What is Lactulose used for?

Draws water into the gut to soften stools; also used in liver disease.

How does Lactulose work?

A sugar the body cannot absorb. It draws water into the bowel to soften stools, and in liver disease it reduces ammonia absorbed from the gut.

How should I take Lactulose?

Usually 15 ml twice a day for constipation; it can take 2 to 3 days to work. Liver doses are higher and set by the doctor.

What are the side effects of Lactulose?

Common: Wind, bloating, stomach cramps, diarrhoea at high doses. Get help straight away for: Severe diarrhoea with dizziness, confusion in people with liver disease.

Does Lactulose interact with other medicines?

No important interactions.

Is Lactulose safe in pregnancy and breastfeeding?

Safe in pregnancy and breastfeeding.

Does Lactulose need a prescription in India?

It is usually sold without a prescription in India, but ask a pharmacist if you take other medicines or have a long-term illness.

Which brands contain Lactulose?

Duphalac.

Sources and further reading

NHS (UK National Health Service) and MedlinePlus (US National Library of Medicine) are free, reviewed medicine guides. Brand names and doses there may differ from India.

Last reviewed 31 October 2026. Written by Satya Babu from standard prescribing information.

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For information only, not medical advice. This page is a plain-language summary written from standard prescribing information and the public guides linked below. Brands sometimes change their formula, so always check the composition printed on the pack. Doses here are typical adult doses; yours may differ. Do not start, stop or change a medicine without your doctor or pharmacist, and keep all medicines away from children. In an emergency, call 112 (India) or your local emergency number.