Insulin Glargine: uses, side effects & brands

Written & medically reviewed by Dr. Sanjay Anbu, MBBS · Last reviewed 5 November 2026

Glargine is a long-acting background insulin given once daily. It belongs to the Injectable diabetes medicine (insulin analogue & GLP-1) group. These injectable medicines control blood sugar; GLP-1 types also aid weight loss.

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Drug type — dosing is set by your doctor

Measure	Range
Drug class	Injectable diabetes medicine (insulin analogue & GLP-1)
Type	Prescription
Dose	Individual — ask your doctor or pharmacist

What it is used for

Type 1 diabetes (with mealtime insulin)
Type 2 diabetes when tablets are not enough
Steady background sugar control day and night

Common brand names

India: Lantus, Basalog, Glaritus
Worldwide: Lantus, Basaglar, Toujeo

Common side effects

Low blood sugar (hypoglycaemia)
Redness or itching at the injection site
Lumps under the skin if the same spot is used repeatedly
Weight gain

Before taking it — precautions

Never mix with other insulins in the same syringe
Rotate injection sites and check the pen type every time — products differ
Illness, alcohol, exercise and new medicines can change sugar levels — tell your doctor

When to see a doctor urgently

Low sugar: shaking, sweating, confusion or fits — take fast sugar and get help (urgent)
Very high sugar with vomiting, deep breathing or drowsiness (urgent)
Swelling of the face, widespread rash or difficulty breathing (urgent)

Not a prescription — no dose shown. The right dose of insulin glargine depends on age, weight, kidney/liver function and the condition, so MedDroid does not show a dose here. Always get your dose from a doctor or pharmacist and the leaflet inside the pack. General educational information only.

Frequently asked questions

What if I miss a dose?

Ask your doctor in advance what to do; do not double up without advice.

Why does it not cover meals?

Glargine releases slowly with no peak, so it gives background insulin only; meals may need a rapid insulin.

How do I store it?

Keep unopened pens in the fridge (never frozen); the pen in use can stay at room temperature away from heat for the time on the label.

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Sources & further reading

Reviewed by Dr. Sanjay Anbu, MBBS. MedDroid is an AI medical assistant and can make mistakes. It provides general health information, not a diagnosis or medical advice — always consult a qualified clinician. In an emergency, contact your local emergency number immediately.