A long-acting (basal) insulin
Insulin detemir
A long-acting (basal) insulin that gives background insulin cover, often taken once or twice a day.
What is Insulin detemir?
Insulin detemir is a long-acting insulin that provides background (basal) insulin cover, helping keep blood glucose steady between meals and overnight. Depending on a person's needs it is injected under the skin once or twice a day, and in type 1 diabetes it is combined with a separate mealtime insulin. Because it lowers blood glucose, the main risk is a hypo, so it is important to recognise and treat the warning signs. Always rotate injection sites and never share your pen or needles with anyone else.
Education and reference only. This is a plain-language guide to Insulin detemir — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Insulin detemir is a long-acting insulin analogue used as the background, or basal, part of insulin treatment in type 1 and type 2 diabetes. It binds to a protein in the blood so that it is released slowly and gives steady cover over an extended period, though its action is a little shorter than some other basal insulins, so it is sometimes taken twice a day. This background cover handles the glucose released between meals and overnight, and in type 1 diabetes it is paired with a fast-acting mealtime insulin. It comes in prefilled pens and cartridges.
How it works
Insulin lets glucose move from the blood into the cells for energy and tells the liver to stop releasing extra glucose. In diabetes the body makes too little insulin or cannot use it properly, so glucose rises. Detemir replaces the slow, steady background insulin a healthy pancreas would supply; it attaches to a blood protein and is released gradually, smoothing out blood glucose between meals and overnight. Because its effect does not always last a full day, some people take it twice daily for even cover.
Company & origin
Originated / developed by: Novo Nordisk.
A long-acting insulin analogue developed by Novo Nordisk and used in the UK as a background insulin, sometimes taken once or twice a day depending on individual needs.
What it treats
Conditions Insulin detemir is used for
Practical use
How to take Insulin detemir
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Inject under the skin once or twice a day as advised, at roughly the same times, into the tummy, thigh, buttock or upper arm.
- Rotate your injection site within an area each time to prevent lumpy or hardened skin that changes absorption.
- Use a new needle each time, prime the pen as instructed, and never share a pen or needle with anyone else.
- Detemir is a clear solution; do not shake it or mix it in the same syringe with other insulins.
- Recognise hypo warning signs and always carry fast-acting sugar such as glucose tablets or a sugary drink.
- On sick days keep taking your insulin, check your blood glucose more often and follow your sick-day plan.
Weighing it up
Advantages & disadvantages of Insulin detemir
Advantages
- Gives steady background cover and tends to be associated with relatively stable, predictable effects.
- Can be tailored to once- or twice-daily use depending on what gives the best control.
- Often linked with somewhat less weight gain than some other insulins.
Disadvantages
- Like all insulin it can cause hypoglycaemia, which needs prompt treatment and ongoing awareness.
- Its action may not last a full day for everyone, so some people need two injections a day.
- It only covers background needs, so a separate mealtime insulin is still required in type 1 diabetes.
Practical use
Good to know
Detemir is a background insulin, not a mealtime one, so it controls glucose between meals and overnight rather than the rise after eating. Some people find one injection a day is enough, while others need it twice a day for steady cover; your team will advise. The key safety point is hypoglycaemia: warning signs include shakiness, sweating, hunger, a fast heartbeat and confusion, treated with fast-acting sugar then a snack. Always inject under the skin, rotate sites to avoid lumpy skin that affects absorption, and never share a pen or needle because of infection risk. On sick days do not stop your insulin; illness often raises glucose, so keep taking it, monitor more often and follow your sick-day plan.
Who should not take it / use with caution
- It must not be used during an episode of low blood glucose (hypoglycaemia).
- People with a known allergy to insulin detemir or its ingredients should not use it.
- It is not suitable on its own for diabetic ketoacidosis, which needs urgent hospital treatment with fast-acting insulin.
Monitoring
- Regular blood glucose checks, and HbA1c over time, to guide the background insulin amount.
- Reviewing injection sites for lumps or hardened skin that can affect absorption.
- Watching the frequency and pattern of hypos, especially overnight, to adjust treatment.
Side effects
- Hypoglycaemia (low blood glucose) is the most important side effect, with shakiness, sweating, hunger and confusion.
- Redness, itching or lumpy, hardened skin at injection sites if sites are not rotated.
- Weight gain and, rarely, allergic reactions or swelling.
Key interactions
- Other glucose-lowering medicines, alcohol and some painkillers can increase the risk of a hypo.
- Steroids, some diuretics and certain other medicines can raise blood glucose and reduce insulin's effect.
- Beta-blockers can mask the warning signs of a hypo, so extra glucose monitoring may be needed.
Available as: Solution for injection under the skin, in prefilled pens and cartridges.
Answers
Insulin detemir: frequently asked questions
Is insulin detemir a background or mealtime insulin?
It is a long-acting background (basal) insulin; in type 1 diabetes a separate fast-acting insulin is still needed for meals.
Do I take it once or twice a day?
It depends on the person; some need one injection a day and others two for steady cover. Your diabetes team will advise what suits you.
What should I do for a hypo?
Treat it straight away with fast-acting sugar such as glucose tablets or a sugary drink, then a snack; learn the warning signs and always carry sugar.
Can I share my insulin pen?
No. Pens and needles must never be shared, even with a new needle, because of the risk of passing on infection.
Should I keep taking it when I am ill?
Yes. Illness often raises blood glucose, so keep taking your insulin, monitor more often and follow your sick-day advice.
The wider class
About Insulin
Insulin detemir belongs to the insulin class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
Browse by body system
Authoritative sources
- BNF
- NICE CKS
Building a medicines information resource?
We create evidence-led, dose-free drug and formulary references for teams.