More than eighty years ago, insulin was discovered, marking a significant milestone in medical history. Today, that discovery has become even more crucial as diabetes, a condition affecting blood sugar levels, ranked as the eighth leading cause of death in the US in 2021.
Managing diabetes requires a careful approach involving medication, lifestyle changes, and regular monitoring. Long-acting insulin analogs like Levemir and Lantus are vital medications for many individuals striving to control their blood sugar levels.
In this comparison, we explore the differences between Levemir and Lantus, including how they work, how effective they are, possible side effects, and factors to consider when choosing treatment. Whether you’re newly diagnosed or experienced in managing diabetes, understanding these differences can help you make better decisions about your health.
Key Differences Between Levemir and Lantus
Parameters Levemir Lantus Cost (manufacturer’s suggested retail price) $161.77 for pre-filled pens and $107.85 for a 10 ml vial $438.07 for pre-filled pens and $292.07 for a 10 ml vial Prescription requirement Prescription-only Prescription-only Active ingredient Insulin detemir Insulin glargine Biosimilars Not available Available (Semglee and Rezvoglar) Approved indications Type 1 and type 2 diabetes Type 1 and type 2 diabetes Forms Prefilled pen and vial Prefilled pen and vial Route of administration Injection Injection Effectiveness HbA1c lowered by an average of 0.1% to 0.8% for type 1 diabetes and 0.6% to 2% for type 2 diabetes. HbA1c lowered by an average of 0% to 0.7% for type 1 diabetes and up to 1.7% for type 2 diabetes. Side effects Hypoglycemia, allergic reactions, injection site reactions, lipodystrophy, rash, and pruritus. Hypoglycemia, allergic reactions, injection site reactions, lipodystrophy, pruritus, rash, edema, and weight gain. Dosage frequency Once or twice per day Once per day Duration of action Long-acting insulin Long-acting insulin
Efficacy and Safety
Levemir (insulin detemir) and Lantus (insulin glargine) work similarly in controlling blood sugar levels and have similar levels of efficacy. Both are effective and generally well-tolerated.
A 2017 study compared the efficacy and safety of glargine and detemir insulin in non-intensive care unit (non-ICU) hospital patients with diabetes. The results showed no significant difference in mean daily blood glucose levels, mortality rates, hospital complications, or readmission rates between the two groups.
After adjusting for potential confounding variables, there was no statistically significant difference in hypoglycemia rates. Although glargine was associated with a slightly longer hospital stay, this difference may not be clinically important.
Another study focused on the efficacy of insulin detemir versus insulin glargine, specifically for type 2 diabetes mellitus. The analysis revealed no significant differences in glycemic control, as measured by HbA1c levels, or in achieving an HbA1c of 7% or lower, with or without hypoglycemia. Rates of overall, nocturnal, or severe hypoglycemia were also similar between the two treatment groups.
However, insulin detemir was associated with less weight gain compared to insulin glargine. Additionally, patients on insulin glargine required a lower daily basal insulin dose and experienced fewer injection site reactions than those on insulin detemir. No significant differences were found in fasting plasma glucose (FPG) or 24-hour glucose profiles between the groups.
To further investigate, a 2018 systematic review and meta-analysis examined the effectiveness and safety of insulin glargine versus detemir in patients with type 1 diabetes. Out of 705 publications, 8 cohort studies were included, all classified as high quality. The analysis found no statistically significant difference in HbA1c levels between the two insulins.
While insulin detemir had some favorable outcomes, such as fewer episodes of severe hypoglycemia and lower fasting glucose levels, the overall effectiveness and safety of the two insulins were not significantly different.
Side Effects of Levemir vs. Lantus
Levemir and Lantus have similar side effects, with the most common being hypoglycemia (low blood sugar). Hypoglycemia is a significant barrier and limiting factor in managing diabetes, as it can cause unpleasant physical symptoms, potential cognitive impairment in children, and fear and anxiety over future episodes. It can also lead to serious complications, including cardiac arrhythmia, which may result in mortality.
An older study compared the risk of hypoglycemia between twice-daily insulin detemir (Levemir) and once-daily insulin glargine (Lantus) in individuals with type 1 diabetes. The study found that the overall risk was similar for both insulins. However, severe and nocturnal hypoglycemia was significantly less common with insulin detemir (Levemir).
Both medications can also cause allergic reactions and injection site reactions. A randomized, 52-week trial compared insulin detemir with insulin glargine in people with type 2 diabetes who have not yet initiated insulin treatment.
The trial found that injection site reactions were more frequent with detemir compared to glargine (4.5% versus 1.4%). Additionally, the withdrawal rate was higher in the detemir group (21% versus 13%), partly due to adverse effects like injection site reactions.
Other common side effects of Levemir and Lantus include:
- Upper respiratory tract infections
- Headache
- Edema (swelling in the arms or legs)
- Lipodystrophy (abnormal or degenerative conditions of the body’s fat tissue)
- Rash
- Pruritus (itching)
These side effects should be monitored by healthcare providers to manage and adjust treatment as necessary.
Weight Gain as a Side Effect

Many ask, “Will Levemir cause weight gain?” or “Will Lantus cause weight gain?” Unfortunately, weight gain is a common side effect of insulin therapy or intensifying insulin doses. On average, insulin therapy is associated with a weight gain of 8.8-11 lbs.
So, why does Lantus or Levemir cause weight gain? This can be due to reduced glycosuria, which is the loss of glucose through urine, and overeating in response to low blood sugar. Additionally, insulin promotes the creation and storage of fat (lipogenesis) and can affect brain receptors that control appetite.
Potential weight gain can be a psychological barrier to starting insulin, and actual weight gain can affect patients’ willingness to continue treatment, leading to poor adherence and suboptimal blood sugar control. Weight gain is not just a cosmetic concern; it can also negatively impact cardiovascular health by worsening blood pressure and cholesterol levels.
Insulin detemir (Levemir) has been shown in high-quality studies to help prevent weight gain in people with both type 1 and type 2 diabetes. This weight-loss benefit is most noticeable in people with higher body fat (measured by BMI).
In a 2008 study, it was found that detemir led to slightly less weight gain compared to glargine, with reported increases of 6.6 lbs and 8.6 lbs, respectively. This was supported by a 52-week, multinational, open-label, parallel-group, noninferiority, treat-to-target trial, which reported a weight gain of 6.2 lbs with detemir versus 8.4 lbs with glargine.
The exact reasons for this weight-loss effect are not fully understood, but researchers found that insulin detemir tends to act more in the brain than in other parts of the body. This might be because it can more easily cross the barrier that protects the brain. Since insulin can reduce appetite when it acts in the brain, this might help explain why detemir helps prevent weight gain.
Active Ingredient and Mechanism of Action
Insulin detemir and insulin glargine are both long-acting insulins, but due to their unique molecular modifications, they achieve their prolonged action through different mechanisms.
Levemir (insulin detemir)
Insulin detemir is a recombinant DNA-produced human insulin analog. The key modification is attaching a 14-carbon fatty acid (myristic acid) to the B29 lysine residue. This modification increases the molecule’s affinity for binding to albumin in the bloodstream.
This means that insulin detemir is modified with a fatty acid attached. When injected, much of it binds to a protein in the blood called albumin. This binding acts like a storage, releasing the insulin slowly over time. Because it’s released slowly, it provides a steady insulin level, helping control blood sugar over a long period.
Lantus (insulin glargine)
Insulin glargine is also a recombinant DNA-produced human insulin analog, but with different structural modifications. It has two extra arginine molecules attached to the B-chain (B31 and B32) and a substitution of glycine for asparagine at the A21 position. These modifications make glargine soluble at an acidic pH (around pH 4) but less soluble at the physiological pH (around pH 7.4).
This means that when injected, it forms tiny particles (microcrystals) because of the body’s pH level. These particles dissolve slowly, gradually releasing insulin into the bloodstream. This results in a consistent insulin level throughout the day without sharp peaks.
To summarize, insulin detemir binds to a blood protein and is released slowly, while insulin glargine forms tiny particles under the skin that dissolve over time. Both provide long-lasting insulin action.
Approved Indications
In the spring of 2001, the first long-acting insulin analog, insulin glargine, was launched in the US. Following this, insulin detemir was also introduced and is now accessible.
Both Levemir (insulin detemir) and Lantus (insulin glargine) are prescription medications that have received FDA approval for controlling high blood sugar levels in adults and children with type 1 or type 2 diabetes.
Specifically, Lantus is approved for use in children (aged 6 and above) and adults with type 1 diabetes, and adults with type 2 diabetes. In contrast, Levemir is approved for adults and children aged 2 years and older with type 1 diabetes, as well as adults with type 2 diabetes.
Dosing and Administration
Both Levemir and Lantus are administered via subcutaneous injection. However, their dosing frequencies differ, with Lantus typically given once daily and Levemir administered twice daily, based on the patient’s requirements and their healthcare provider’s guidance.
Dosage adjustments should be tailored to individual metabolic demands, regular blood glucose monitoring, glycemic management goals, diabetes type, and prior insulin therapy. Below is a summary of the dosage and administration guidelines for treating both type 1 and type 2 diabetes with Levemir and Lantus.
| Levemir | Lantus | |
| Forms |
|
|
| Strength | 100 units per mL | 100 units per mL |
| Frequency | Once or twice per day | Once per day |
| Dosage for type 1 diabetes (starting dose) | About 1/3 of the total daily insulin requirement | About 1/3 to 1/2 of the total daily insulin requirement |
| Dosage for type 2 diabetes (starting dose) | 0.1 to 0.2 units/kg or 10 units per day, which may be adjusted over time based on the patient’s blood sugar levels | 0.2 units/kg, up to 10 units per day, which may be adjusted over time based on the patient’s blood sugar levels |
Source: Lantus Website and Levemir Website
For most individuals with type 1 diabetes, the typical insulin requirement ranges from 0.5 to 1 unit per kilogram (kg) of body weight per day. Patients should consult their healthcare provider for personalized guidance on determining their daily insulin needs and calculating the appropriate dosage of Lantus or Levemir. Dosage adjustments may be made over time in response to changes in blood sugar levels.
Reminder
The Levemir FlexTouch pen was discontinued in February 2023. Moreover, Novo Nordisk is discontinuing Levemir FlexPens and vials in the US, effective December 31, 2024.
Switching to Other Insulin Therapies
Switching to other insulin therapies may be done for various reasons, such as achieving better glycemic control, managing side effects, or adapting to lifestyle changes.
| Clinical Scenario | Recommendation |
| Levemir to Lantus conversion | Consider converting unit-per-unit. A lower once-daily dose may be needed. |
| Levemir to Tresiba conversion | Perform a unit-per-unit conversion of the total daily dose and administer it once daily. Alternatively, reduce the dose by 20% and administer once daily, particularly applicable for patients with type 1 diabetes (in Canada), those using twice-daily basal insulin (in Canada), or pediatric patients (in the US).
Do not increase the Tresiba dose more frequently than every 3 to 4 days. |
| Levemir to Toujeo conversion |
It may take ?5 days to see the maximum effect of the selected dose of Toujeo. Do not increase the Toujeo dose more frequently than every 3 to 4 days. |
| Levemir to NPH conversion |
|
| Levemir to Basaglar conversion | Consider converting unit-per-unit. A lower once-daily dose may be needed. |
| Lantus to Tresiba conversion | Perform a unit-per-unit conversion of the total daily dose and administer it once daily. Alternatively, reduce the dose by 20% and administer once daily, particularly applicable for patients with type 1 diabetes (in Canada), those using twice-daily basal insulin (in Canada), or pediatric patients (in the US).
Do not increase the Tresiba dose more frequently than every 3 to 4 days. |
| Lantus to Toujeo conversion | Convert unit-per-unit and give once daily. To maintain control, expect to need a higher daily dose (about 10% to 18%) of Toujeo.
It may take ?5 days to see the maximum effect of the selected dose of Toujeo. Do not increase the Toujeo dose more frequently than every 3 to 4 days. |
| Lantus to Basaglar conversion | Has no dosing differences for insulin initiation. |
| Lantus to Semglee conversion | Interchangeable biosimilar. |
| Lantus to NPH conversion |
|
Source: Pharmacist’s Letter
It’s essential to consult with a healthcare provider before making any adjustments to insulin therapy to ensure a smooth transition and minimize potential risks. They can provide personalized advice based on individual health status, medication history, and treatment goals.
Levemir vs. Lantus Biosimilar Availability
Another key distinction between Levemir and Lantus is the availability of biosimilars. Levemir currently lacks any available biosimilars, while Lantus has two FDA-approved interchangeable biosimilars, namely:
- Semglee (insulin glargine-yfgn)
- Rezvoglar (insulin glargine-aglr)
Biosimilars are biological products that are highly similar to an already approved biological medicine, known as the reference product. However, they are not identical due to the inherent complexity of biological molecules. Biosimilars are created to be comparable in terms of quality, safety, and efficacy to the reference product.
Note that biosimilars are not the same as generic versions of a medication. Biosimilars and generics offer cost-effective alternatives to brand-name drugs, but they differ in their replication process and regulatory pathways.
Generics are identical copies of small-molecule drugs produced once patent protection expires, while biosimilars are similar but not identical versions of biologics undergoing rigorous testing to ensure similarity in safety, efficacy, and quality.
Interchangeable biosimilars are a designation in the US that signifies a higher level of similarity to the reference biologic drug than standard biosimilars. To be designated as interchangeable, a biosimilar must demonstrate that it produces the same clinical result as the reference product in any given patient and that switching between the interchangeable biosimilar and the reference product does not result in any additional risks compared to using the reference product alone.
This designation allows pharmacists to substitute the interchangeable biosimilar for the reference product without needing prescriber intervention, similar to how generic drugs are substituted for brand-name drugs. It provides added assurance to healthcare providers and patients regarding the safety and efficacy of interchangeable biosimilars.
Cost of Levemir vs. Lantus
The list price of Lantus is $438.07 for pre-filled pens and $292.07 for a 10 ml vial. The retail price for a pack of 5 Lantus SoloStar pens in the US varies between $408 and $550, each SoloStar pen contains 3 mL of Lantus.
The list price for a Levemir FlexPen package of 5 prefilled pens, each containing 3 mL, is $161.77. The list price for a 10 mL vial of Levemir is $107.85. Retail prices are approximately $553.99 for the FlexPens and $127.84 for the vial.
Save on Levemir & Lantus through Pharma Giant!
At Pharma Giant, you can save up to 90% on prescription medications such as Levemir and Lantus. Plus, you can enjoy additional discounts and offers when ordering larger quantities. To save more, use the coupon code PGSAVE10 for a 10% discount on your first order.
Pharma Giant promises expedited delivery, with medications typically arriving within 3-5 business days.
Duration of Action of Levemir and Lantus
Levemir and Lantus are classified as long-acting insulins, beginning to take effect within 1 to 2 hours and maintaining a steady level of action for 12 to 24 hours. Typically administered in the evening following meals, their extended duration of action minimizes the need for frequent dosing throughout the day.
Final Thoughts on Levemir vs Lantus
Levemir (insulin detemir) and Lantus (insulin glargine) are long-acting insulins prescribed for both type 1 and type 2 diabetes. While they share similarities in effectiveness and side effects, one key difference is their dosing frequency. Levemir may require two daily doses, whereas Lantus is typically injected once daily.
Additionally, Levemir may be preferred by individuals concerned about nocturnal hypoglycemia and weight gain, whereas Lantus has shown fewer injection site reactions. Both glargine and detemir offer promising options as basal insulin analogs, consulting with your healthcare provider can help determine the most suitable insulin for your needs.
Frequently Asked Questions
Related Articles
Sources
Silva, T. B., Almeida, P. H., Araújo, V. E., De Assis Acurcio, F., Júnior, A. a. G., Godman, B. B., & Alvares, J. (2018). Effectiveness and safety of insulin glargine versus detemir analysis in patients with type 1 diabetes: systematic review and meta-analysis. Therapeutic Advances in Endocrinology and Metabolism, 9(8), 241–254. https://doi.org/10.1177/2042018818781414
Swinnen, S. G., Simon, A. C., Holleman, F., Hoekstra, J. B., & Devries, J. H. (2011). Insulin detemir versus insulin glargine for type 2 diabetes mellitus. The Cochrane database of systematic reviews, 2011(7), CD006383. https://doi.org/10.1002/14651858.CD006383.pub2
Galindo, R. J., Davis, G. M., Fayfman, M., Reyes-Umpierrez, D., Alfa, D., Peng, L., Tamler, R., Pasquel, F. J., & Umpierrez, G. E. (2017). Comparison of efficacy and safety of Glargine and Detemir insulin in the management of inpatient hyperglycemia and diabetes. Endocrine Practice, 23(9), 1059–1066. https://doi.org/10.4158/ep171804.or
Hermansen, K., & Davies, M. (2006). Does insulin detemir have a role in reducing risk of insulin?associated weight gain? Diabetes, Obesity & Metabolism/Diabetes, Obesity and Metabolism, 9(3), 209–217. https://doi.org/10.1111/j.1463-1326.2006.00665.x
Hennige, A. M., Sartorius, T., Tschritter, O., Preissl, H., Fritsche, A., Ruth, P., & Häring, H. U. (2006). Tissue selectivity of insulin detemir action in vivo. Diabetologia, 49(6), 1274–1282. https://doi.org/10.1007/s00125-006-0192-9
Poon, K., & King, A. B. (2010). Glargine and detemir: Safety and efficacy profiles of the long-acting basal insulin analogs. Drug, healthcare and patient safety, 2, 213–223. https://doi.org/10.2147/DHPS.S7301
Rosenstock, J., Davies, M., Home, P. D., Larsen, J., Koenen, C., & Schernthaner, G. (2008). A randomised, 52-week, treat-to-target trial comparing insulin detemir with insulin glargine when administered as add-on to glucose-lowering drugs in insulin-naive people with type 2 diabetes. Diabetologia, 51(3), 408–416. https://doi.org/10.1007/s00125-007-0911-x
Pieber, T. R., Treichel, H. C., Hompesch, B., Philotheou, A., Mordhorst, L., Gall, M. A., & Robertson, L. I. (2007). Comparison of insulin detemir and insulin glargine in subjects with Type 1 diabetes using intensive insulin therapy. Diabetic medicine : a journal of the British Diabetic Association, 24(6), 635–642. https://doi.org/10.1111/j.1464-5491.2007.02113.x
Hollander, P., Cooper, J., Bregnhøj, J., & Pedersen, C. B. (2008). A 52-week, multinational, open-label, parallel-group, noninferiority, treat-to-target trial comparing insulin detemir with insulin glargine in a basal-bolus regimen with mealtime insulin aspart in patients with type 2 diabetes. Clinical therapeutics, 30(11), 1976–1987. https://doi.org/10.1016/j.clinthera.2008.11.001
Philips, J. C., & Scheen, A. (2006). Insulin detemir in the treatment of type 1 and type 2 diabetes. Vascular health and risk management, 2(3), 277–283. https://doi.org/10.2147/vhrm.2006.2.3.277
Thota, S., & Akbar, A. (2023, July 10). Insulin. StatPearls – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK560688/#
FDA. (2019). HIGHLIGHTS OF PRESCRIBING INFORMATION OF LEVEMIR. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/021536s054lbl.pdf
FDA. (2022). HIGHLIGHTS OF PRESCRIBING INFORMATION OF LANTUS. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/021081s076lbl.pdf
Levemir (insulin detemir)




