Lantus is a U-100 insulin glargine product used for background insulin coverage. Its vial and SoloStar pen contain the same concentration but require different handling and supplies.
The approved uses and formulations described here follow US prescribing information. They may differ in other countries.
| Medicine detail | Details |
|---|---|
| Active ingredient(s) | insulin glargine |
| Medicine class | Long-acting basal insulin |
| Forms and strengths | U-100 solution: 10 mL vial and 3 mL SoloStar pen |
Background glucose control
The US label covers adults and children with diabetes. Lantus is long acting and is not a treatment for diabetic ketoacidosis. It is generally used once daily at the same time, with an individualized dose. In type 1 diabetes, the complete regimen also addresses mealtime insulin needs.
Source: [1]
Vial and pen identification
The labeled 10 mL vial contains 1,000 units; a 3 mL U-100 SoloStar pen contains 300 units. Total contents are not an injection dose. Check the device instructions and prescribed units, and never infer a dose from the volume of a different insulin product.
Source: [1]
Important handling limits
Do not mix or dilute Lantus, and never share a pen. Follow its storage and in-use disposal instructions, including the exact device supplied. If a prescription changes from vial to pen, obtain training and the correct supplies rather than assuming the old technique transfers unchanged.
Source: [1]
Insulin-related risks
Low blood glucose and low potassium can be serious. Meals, activity, illness and other medicines can affect insulin needs. Product changes and dose adjustments require clinical supervision and glucose monitoring. Missing insulin unexpectedly can also be dangerous.
Source: [1]
Other insulin glargine products
Basaglar and other medicines also contain insulin glargine, but concentrations, devices and instructions can differ. Toujeo is not the same U-100 presentation as Lantus. Any change needs the prescribing team’s guidance, including the dose and monitoring; sharing an ingredient does not make all products interchangeable.
Source: [1]
Questions and answers
Is Lantus a U-300 insulin?
No. Lantus is U-100; a different glargine brand may use a different concentration.
Can Lantus be mixed with another insulin?
The Lantus label says not to mix or dilute it.
Does one SoloStar pen contain one dose?
No. It is a multidose pen; the individual injection is the prescribed number of units.
Related reading
Sources
Sources checked 1 October 2026. This information does not replace advice from your healthcare professional. For complete warnings and instructions, read the product information and consult the prescribing team.
Reviewed by: Mattias Hagman, PhD
About the reviewer:
Dr Mattias Hagman (PhD, University of Sydney) has an academic background and experience working with healthcare-related content and regulated industries. He has lecturing experience at international universities, including Stockholm University and the University of Malta.
Last reviewed: October 2026