From the FDA Drug Label
The median time between subcutaneous injection and the end of pharmacological effect was 14.5 hours (range: 9. 5 to 19.3 hours) for NPH insulin, and 24 hours (range: 10. 8 to >24 hours) (24 hours was the end of the observation period) for Insulin Glargine. The duration of action after abdominal, deltoid, or thigh subcutaneous administration of Insulin Glargine was similar The time course of action of insulins, including Insulin Glargine, may vary between patients and within the same patient.
The duration of action of insulin glargine (Lantus) is approximately 24 hours, with a range of 10.8 to >24 hours 1.
From the Research
Insulin glargine has a duration of action of approximately 24 hours. This long-acting insulin analog is designed to provide a steady, basal level of insulin throughout the day with minimal peaks. After subcutaneous injection, glargine forms microprecipitates in the tissue, which slowly dissolve and release insulin into the bloodstream at a relatively constant rate. This pharmacokinetic profile allows for once-daily dosing for most patients, typically administered at the same time each day to maintain consistent blood glucose control. Some patients may experience slightly shorter durations of effect (20-22 hours) or longer durations (up to 26 hours), depending on individual factors such as dose, injection site, and metabolic variability. The long, flat action profile of glargine helps minimize the risk of nocturnal hypoglycemia compared to older intermediate-acting insulins like NPH. For optimal glycemic control, patients should maintain consistent timing of their daily glargine injection and monitor blood glucose levels regularly to ensure adequate 24-hour coverage. According to the most recent study 2, the duration of action of insulin glargine is dose-dependent, but in the clinically relevant range, it is close to 24 hours in people with type 1 diabetes and in excess of this in people with type 2 diabetes.
Key points to consider:
- Insulin glargine provides a steady, basal level of insulin throughout the day with minimal peaks
- The pharmacokinetic profile allows for once-daily dosing for most patients
- Individual factors such as dose, injection site, and metabolic variability may affect the duration of action
- The long, flat action profile of glargine helps minimize the risk of nocturnal hypoglycemia
- Consistent timing of daily glargine injection and regular blood glucose monitoring are essential for optimal glycemic control, as supported by studies 3, 4, 5, 6.