Is Lantus Long Acting? Plus, 7 Other Lantus FAQs Answered
Key takeaways:
Lantus (insulin glargine) is a long-acting (basal) insulin for diabetes. It’s usually injected once a day. Lantus shouldn’t be mixed with other insulins in the same syringe.
Lantus is absorbed slowly by the body, taking about 1.5 to 2 hours to start working. But its effects last for 24 hours, providing a steady amount of insulin during this time.
Lantus doesn’t have a generic. Instead, it has biosimilars (Semglee and Rezvoglar) and an unbranded version. There are also a few other insulin glargine products available, including Basaglar, Toujeo, and Toujeo Max.
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Table of contents
Lantus (insulin glargine), a popular long-acting insulin, has been around for over 20 years. Even so, questions still arise about how long it takes to work, whether it has a generic version, and more. And even if you know the answer, you may be curious as to why — even if you’ve been using Lantus for years.
Below, we answer eight common questions about Lantus to help you better understand your medication.
1. Is Lantus long acting?
Yes. Lantus is considered a long-acting insulin. Its effects last for 24 hours, which is why you usually only need to inject it once a day. Lantus helps manage your blood glucose levels throughout the day, even when you’re not eating. So, it’s sometimes called “background” or “basal” insulin.
Most long-acting insulins work for 24 hours. But there are some that work longer, including Tresiba (insulin degludec), which lasts up to 42 hours.
2. How long does it take Lantus to work?
After you inject Lantus, it’s slowly released and absorbed by the body. So, it doesn’t take effect right away. It usually takes about 1.5 to 2 hours for Lantus to start working. Toujeo, a concentrated version of insulin glargine, takes longer — about 6 hours.
3. Does Lantus have a peak time?
No. Lantus does not have a peak time. Instead, it delivers a slow and steady amount of insulin throughout the day. This is different from shorter-acting insulins, which cause insulin levels to climb more quickly, peak, then fall back down.
4. What’s the maximum dose of Lantus?
There’s no specified maximum dose of Lantus. However, there are limits to how much you can inject at a time.
For example, each Lantus SoloStar pen contains 300 total units of insulin. You can inject up to 80 units at a time. A Lantus vial contains 1,000 total units of insulin. Using a U-100 syringe, you can measure up to 100 units (1 mL of liquid) per injection. But for higher insulin doses, injecting a larger volume of liquid can be painful. What’s more, you may not absorb the insulin the same way as with lower volumes.
In this case, Toujeo or Toujeo Max may be an option to consider. These products contain a greater amount of insulin glargine in a smaller amount of liquid, making larger doses more manageable. The Toujeo pen can provide 80 units per dose, but with less liquid than Lantus. The Toujeo Max pen can provide up to 160 units of insulin at a time.
5. Does Lantus have a generic?
No. Lantus doesn’t technically have a generic. Lantus is considered a biologic — a medication made using a living system. Instead of generics, biologics have biosimilars, which are highly similar (but not identical) to the original (reference) biologic.
Lantus has two biosimilars (Semglee and Rezvoglar) and an unbranded version. There are also a few other insulin glargine products, including Basaglar, Toujeo, and Toujeo Max.
6. Can Lantus and Humalog be mixed?
No. It’s not recommended to mix Lantus with any other insulin in the same syringe, including Humalog (insulin lispro). That’s because the other insulin may interfere with the acidity of Lantus, which plays an important role in how it’s released in the body. Lantus and other insulins should be injected separately.
7. Is Ozempic or Lantus better?
Ozempic (semaglutide) and Lantus are two injectable diabetes medications. Neither medication is “better” than the other. In fact, there are specific reasons why you might be prescribed Ozempic, Lantus, or both together.
If you have Type 2 diabetes, for example, a long-acting insulin like Lantus is usually recommended if your blood glucose levels or hemoglobin A1C (average blood glucose over 3 months) are very high. Long-acting insulins are also usually part of Type 1 diabetes treatment.
Unlike Lantus, Ozempic is only approved for Type 2 diabetes and isn’t a type of insulin. But it does cause your pancreas to release insulin after you eat and lessens the amount of glucose your liver makes. It can also affect your appetite and fullness, resulting in weight loss. What’s more, Ozempic has proven cardiovascular benefits if you have Type 2 diabetes and heart disease.
If you have Type 2 diabetes, Ozempic’s effects can work with Lantus and provide additional benefits. In fact, experts recommend adding a medication like Ozempic to insulin therapy. But there are certain situations where Ozempic may not be appropriate. Examples include having a history of certain types of thyroid cancer, pancreatitis, or allergic reactions.
8. Does Lantus affect the kidneys?
Lantus isn’t known to harm the kidneys. But certain side effects, such as hypoglycemia (low blood glucose), may be more likely if you have kidney problems.
As part of your diabetes treatment plan, Lantus can have positive effects on kidney health. That’s because high blood glucose levels can damage the blood vessels in the kidneys over time, leading to chronic kidney disease. Keeping your blood glucose levels within your target range can help lower the risk of this long-term complication.
The bottom line
Lantus (insulin glargine) is a long-acting insulin. It takes about 1.5 to 2 hours to work, and its effects last for 24 hours. Lantus provides slow and steady levels of insulin throughout the day. If you’ve been prescribed other insulins, they shouldn’t be mixed with Lantus.
There’s no specified maximum Lantus dose, but you can only inject so much at a time. If you require higher insulin doses, a concentrated form of insulin glargine (Toujeo and Toujeo Max) may be a better option.
Talk to your healthcare provider or pharmacist if you have additional questions about Lantus.
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References
Alsahli, M., et al. (2015). Hypoglycemia in patients with diabetes and renal disease. Journal of Clinical Medicine.
American Diabetes Association. (n.d). Insulin glargine U-100.
American Diabetes Association Professional Practice Committee. (2024). Pharmacologic approaches to glycemic treatment: Standards of care in diabetes—2024. Diabetes Care.
Atkinson, A. (2016). Chapter 32 - Type 1 diabetes mellitus. Williams Textbook of Endocrinology, Elsevier.
Centers for Disease Control and Prevention. (2022). Types of insulin.
Church, T. J., et al. (2016). Treatment approach to patients with severe insulin resistance. Clinical Diabetes.
Cunningham, A., et al. (2024). Glargine insulin. StatPearls.
Sanofi-Aventis U.S. LLC. (2023). Toujeo- insulin glargine injection, solution [package insert].
U.S. Food and Drug Administration. (2001). Drug approval package: Lantus injection.
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