insulin degludec
Tresiba (insulin degludec) is an ultra-long-acting basal insulin from Novo Nordisk. After injection it forms multi-hexamer chains under the skin that release insulin steadily for more than 24 hours, providing a stable, peakless background level for diabetes control.
This page is based on FDA prescribing information and the EMA medicine record for insulin degludec; the mechanism is explained in plain language, and analogies are used only where they stay accurate.
How it works
Explains what the medicine does in the body, not dosing, side effects, or safety.
An analogy
Think of insulin as the building manager who unlocks cells so glucose can come in. In diabetes the manager is missing or overwhelmed. Insulin degludec is a slow-release stand-in: injected once a day, it forms long chains under the skin that drip manager molecules out evenly for more than 24 hours, keeping the doors open without sudden rushes.
In simple terms
Insulin is the hormone that lets cells absorb glucose from the blood. People with type 1 diabetes make none, and many with type 2 diabetes eventually need extra. Insulin degludec is a modified human insulin designed to last longer than a day. Injected under the skin, it forms long chains that dissolve slowly, providing a constant background insulin level around the clock. This steady supply holds blood sugar stable between meals and through the night.
In depth
Insulin degludec differs from human insulin by deletion of threonine at B30 and attachment of a hexadecanedioic acid moiety via a glutamic acid spacer at LysB29. After subcutaneous injection, it self-assembles into long multi-hexamer chains at the injection site. Hexamers dissociate slowly from the chain ends, releasing monomers that enter the circulation with a half-life of approximately 25 hours, producing a flat, stable pharmacodynamic profile beyond 24 hours. It provides basal insulin coverage and is paired with rapid-acting insulin or other glucose-lowering agents.
See it in motion
A schematic animation of the mechanism — simplified for clarity, not drawn to scale.
How insulin degludec forms multi-hexamer chains for a 24-hour basal level
- Insulin degludec differs from human insulin by deletion of threonine at B30 and attachment of a hexadecanedioic acid moiety via a glutamic acid spacer at LysB29.
- After subcutaneous injection, it self-assembles into long multi-hexamer chains at the injection site.
- Hexamers dissociate slowly from the chain ends, releasing monomers that enter the circulation with a half-life of approximately 25 hours, producing a flat, stable pharmacodynamic profile beyond 24 hours.
- It provides basal insulin coverage and is paired with rapid-acting insulin or other glucose-lowering agents.
Target: Insulin receptor
The receptor through which insulin tells muscle, fat, and liver cells to take up glucose; a steady basal insulin level keeps glucose stable between meals and overnight.
Approved uses
Approved uses differ by country and change over time. Always follow your local prescribing information.
Approved uses in United States
FDA- To improve glycemic control in patients 1 year of age and older with diabetes mellitus
Approved uses in European Union
EMA- Treatment of diabetes mellitus in adults
Official sources
The statements on this page trace back to these records.
- U.S. Food and Drug Administration: insulin degludec prescribing information
U.S. Food and Drug Administration
- Tresiba (insulin degludec) — Summary of product characteristics and package leaflet, English version
European Medicines Agency
- Emc SmPC: Insulin Degludec (UK licensed product)
Medicines and Healthcare products Regulatory Agency (EMC)
This page explains how the medicine works — it isn’t the patient leaflet. For anything that applies to you, read the leaflet that came with your medicine or ask your pharmacist.
MedUnfold provides educational content and is not medical advice. Always follow your local prescribing information and healthcare professional.