Yes, Lantus and glargine are the same medication
Lantus is simply the brand name for insulin glargine, which is the active pharmaceutical ingredient. They refer to the exact same medication, just as "Tylenol" and "acetaminophen" are the same drug 1.
Key Points to Understand
Active Ingredient vs. Brand Name:
- Insulin glargine = the generic/chemical name of the medication
- Lantus = the brand name manufactured by Sanofi-Aventis
- Each milliliter of Lantus contains 100 Units (3.6378 mg) of insulin glargine 1
Chemical Identity: Insulin glargine is a recombinant human insulin analog produced by recombinant DNA technology. It differs from human insulin by having glycine replace asparagine at position A21, with two arginines added to the C-terminus of the B-chain 1. This modification creates its long-acting (up to 24-hour) duration of action.
Important Clinical Considerations
Biosimilar Products: While Lantus is the original reference product, biosimilar versions of insulin glargine now exist (such as Basaglar/LY IGlar and Semglee), which contain the same active ingredient but are manufactured through different processes 2, 3, 4. These biosimilars have demonstrated pharmacokinetic and pharmacodynamic similarity to Lantus 5, 3.
Practical Implications:
- When prescribing, you can write either "insulin glargine" or "Lantus"
- If writing "insulin glargine," the pharmacy may dispense Lantus or an approved biosimilar depending on formulary
- If you specifically want the Sanofi brand, write "Lantus" on the prescription
- Different concentrations exist (U-100 vs U-300 glargine), so specify the concentration 6
Common Pitfall: Do not confuse different insulin glargine products - Lantus (U-100), Toujeo (U-300 glargine), and biosimilars all contain insulin glargine but have different formulations and may require dose adjustments when switching 6.