Basal insulin (also Long-term insulin or Basic insulin called) covers the body's continuous basic need for insulin - even at night and between meals. It simulates the natural basal secretion of the pancreas and ensures stable fasting blood sugar levels. Modern basal insulins are usually only injected once a day.
Mode of action
Basal insulin is released slowly and evenly from the subcutaneous fatty tissue. It inhibits the liver's glucose production and keeps blood sugar stable for many hours without sharp spikes. In contrast to bolus insulin (mealtime insulin), it does not affect food intake, but rather the basic requirement.
Important active ingredients and preparations (as of 2026)
| active ingredient | Brand names | Duration of action | Injection frequency |
|---|---|---|---|
| Insulin glargine U100 | Lantus, Abasaglar | approx. 24 hours | 1× daily |
| Insulin glargine U300 | Toujeo | up to 36 hours | 1× daily |
| Insulin degludec | Tresiba | up to 42 hours | 1× daily (very flexible) |
| Insulin detemir | Levemir | 18-24 hours | 1-2 times daily |
Advantages
- Stable blood sugar levels over 24 hours
- Lower risk of hypoglycemia than older NPH insulins
- More flexible injection times (especially Tresiba)
- Fewer nighttime hypoglycaemia
Disadvantages and risks
- Hypoglycemia possible if the dose is too high
- Weight gain (typical of all insulins)
- Lipohypertrophy in the absence of injection site rotation
Further information:
→ Diabetes mellitus – knowledge and overview
→ Why hyporest
→ Type 2 diabetes
Sources
- German Diabetes Society (DDG). S3 guideline “Type 2 diabetes”. As of 2025. Available at: www.deutsche-diabetes-gesellschaft.de/leitlinien.
- American Diabetes Association. Standards of Medical Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1). Available at: diabetesjournals.org.
- Robert Koch Institute (RKI). Federal health reporting – diabetes mellitus in Germany. Berlin 2024.
- International Diabetes Federation (IDF). IDF Diabetes Atlas. 11th edition. Brussels 2025. Available at: diabetesatlas.org.
Important note:
The information in this encyclopedia article is intended solely for general and non-binding information. They do not replace medical advice, diagnosis or therapy. If you have any health questions or complaints, please always consult a doctor or qualified healthcare professional. The content was created with the greatest possible care, but errors cannot be completely ruled out.
Last updated: February 26, 2026
