Insulin glargine

Long-acting insulin
PRESCRIPTION ONLY IN INDIA

Insulin glargine is a long-acting insulin found in 3 medicines sold in India, such as Lantus, Toujeo, Basalog. Below: what it is for, how it works, how to take it, side effects, interactions and pregnancy advice.

Also called: glargine

What it is used for

Provides steady background insulin over 24 hours in diabetes.

How it works

A long-acting (basal) insulin that releases slowly over about 24 hours to control background blood sugar.

How to take it

Inject once a day at the same time. Inject under the skin of the tummy, thigh or upper arm, rotating sites. Never share pens. Store spare pens in the fridge (not frozen); the pen in use keeps at room temperature for about 4 weeks.

Common side effects

  • Low blood sugar
  • Weight gain
  • Lumps or dents at injection sites if the same spot is used

Get medical help straight away if

Low blood sugar: shaking, sweating, hunger, confusion or fainting (take 15 g of sugar such as glucose or juice, then food)

Be careful

Can cause low sugar; check sugar levels as advised.

Other medicines and interactions

Alcohol, missed meals and exercise lower sugar further; beta blockers can hide warning signs. Steroids raise sugar. Pioglitazone with insulin can cause fluid build-up.

Pregnancy and breastfeeding

Insulin is the standard treatment for diabetes in pregnancy and is safe while breastfeeding; doses change and need close monitoring.

Brands of Insulin glargine (3)

BasalogLantusToujeo

Common questions

What is Insulin glargine used for?

Provides steady background insulin over 24 hours in diabetes.

How does Insulin glargine work?

A long-acting (basal) insulin that releases slowly over about 24 hours to control background blood sugar.

How should I take Insulin glargine?

Inject once a day at the same time. Inject under the skin of the tummy, thigh or upper arm, rotating sites. Never share pens. Store spare pens in the fridge (not frozen); the pen in use keeps at room temperature for about 4 weeks.

What are the side effects of Insulin glargine?

Common: Low blood sugar, weight gain, lumps or dents at injection sites if the same spot is used. Get help straight away for: Low blood sugar: shaking, sweating, hunger, confusion or fainting (take 15 g of sugar such as glucose or juice, then food).

Does Insulin glargine interact with other medicines?

Alcohol, missed meals and exercise lower sugar further; beta blockers can hide warning signs. Steroids raise sugar. Pioglitazone with insulin can cause fluid build-up.

Is Insulin glargine safe in pregnancy and breastfeeding?

Insulin is the standard treatment for diabetes in pregnancy and is safe while breastfeeding; doses change and need close monitoring.

Does Insulin glargine need a prescription in India?

Yes. In India it is a prescription (Schedule H) medicine, so a pharmacist should sell it only with a doctor's prescription.

Which brands contain Insulin glargine?

Basalog, Lantus, Toujeo.

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.