If you’re looking for the best long-acting insulin, you’ve probably heard of Tresiba and Lantus. In online forums, Tresiba vs. Lantus is one of the most commonly discussed comparisons among people with diabetes. Both are basal insulins designed to provide steady blood sugar control throughout the day and night. However, they differ in their active substance, how they work, how long they last, and how they fit into the patient’s diabetes treatment plan.
If you want to learn more about your diabetes medications, this guide covers everything you need to know about Lantus and Tresiba — including recommended dosages, side effects, and alternatives.
Is Tresiba the Same as Lantus?
Tresiba and Lantus are similar in some aspects. For instance, they’re insulin analogs approved by the FDA to control blood sugar levels in children and adults with diabetes. Both are basal insulins that provide a glucose-lowering effect throughout the day and night. Moreover, they’re taken through once-daily subcutaneous injection.
Tresiba and Lantus have more differences than similarities. For example, the generic name of Tresiba is insulin degludec, which is also its active substance, whereas Lantus contains insulin glargine.
While both are classified as long-acting insulins, Tresiba and Lantus aren’t the same and shouldn’t be used interchangeably.
Tresiba vs. Lantus: 9 Key Differences
How does Tresiba differ from Lantus for diabetes? Here are nine distinctions.
| Feature | Tresiba (Insulin Degludec) | Lantus (Insulin Glargine) |
|---|---|---|
| Type of Insulin | Ultra-long-acting | Long-acting |
| Duration of Action | Up to 42 hours | Around 24 hours |
| Onset of Action | ~1 hour | ~1.5-2 hours |
| Peak Activity | 12 hours after administration | No peak |
| Dosing Flexibility | High – can be taken at different times | Lower – best taken at the same time daily |
| Approved Patient Age | Ages 1 and older | Ages 6 and older |
| Formulations Available | U-100 and U-200 | U-100 only |
| Conversion Complexity | May require titration when switching | 1:1 dose adjustment with biosimilars |
| Average Cost | Often higher | Generally more affordable or has biosimilars |
1. Active Substance
Tresiba contains insulin degludec, while Lantus contains insulin glargine. Both long-acting insulins work for extended hours to provide steady background insulin. Although they mimic the function of human insulin, their chemical structures have been altered to improve absorption and action.
For instance, the amino acid asparagine at position A21 has been replaced by glycine to form the chemical structure of insulin glargine. Two arginines have also been added to the C-terminus of the B-chain.
2. Onset, Peak, and Duration of Action
When comparing insulin glargine vs. Tresiba (insulin degludec), their onset, peak, and duration of action are important features to consider when choosing a better maintenance medication.
Tresiba starts to work within 60 minutes after injection. It peaks 12 hours later and keeps working for up to 42 hours.
Meanwhile, insulin glargine typically starts working within 1.5-2 hours after administration. Lantus doesn’t have a peak time as it releases a steady amount of insulin throughout the day. Its duration of action lasts 24 hours.
3. Tresiba vs. Lantus Dosage and Administration
Here’s a table comparing the dosage information between Lantus and Tresiba.| Indications | Tresiba | Lantus |
|---|---|---|
| Dosage forms and strengths | 100 units/mL (U-100) available as:
|
100 units/mL (U-100) available as:
|
| Administration and timing | For adults:
|
|
| Injection sites |
|
|
| Recommended dose for Type 1 diabetes |
|
|
| Recommended dose for Type 2 diabetes |
|
0.2 units/kg or up to 10 units once daily |
Tresiba vs. Lantus Dosage Recommendations
For adult patients, Tresiba is injected under the skin once a day at any time of the day. This flexible dosing time makes it easier to fit into your schedule.
For children, insulin degludec should be injected once a day at the same time every day. If your child takes their insulin in the morning, the next dose should also be at the same time in the morning. This schedule is less flexible since children’s metabolism can vary more than adults’. A consistent injection schedule should be maintained to achieve predictable blood sugar control.
If you’re starting treatment with Tresiba, your doctor will determine the appropriate initial dose and increase it later when needed. If you miss your dose, you can still take it, but ensure at least an 8-hour window from your last shot.
Lantus is also injected once daily at a fixed time each day. For example, if you take the jab at 8 a.m., your next day’s injection must also be at 8 a.m.
Regarding the Tresiba vs. Lantus dosage schedule, the former offers more flexibility in timing because insulin degludec can be taken at different times. Meanwhile, insulin glargine is best taken at the same time every day.
4. Age Restrictions
The Food and Drug Administration has approved Tresiba to improve blood sugar in adults and children at least 1 year old. It may be used for Type 1 and Type 2 diabetes.
Likewise, the FDA has cleared Lantus for treating adults with Type 1 diabetes or Type 2 diabetes and children at least 6 years old with Type 1 diabetes. It’s not approved for use in pediatric patients below 6.
During your health assessment, your doctor will determine whether Tresiba or Lantus is a better treatment based on age, glycemic index requirements, and other related factors.
5. Drug Interactions
Lantus and Tresiba can interact with two types of medications — those that affect your blood sugar levels and antiadrenergic drugs, like beta-blockers, guanethidine, clonidine, and reserpine. These drugs may affect how your body responds to insulin.
To avoid potential drug interactions, your healthcare provider may adjust your dose. It’s important to always inform your doctor about all drugs you’re taking so they can personally monitor how you respond to your diabetes medications.
6. Lantus vs. Tresiba Side Effects
As long-acting insulins, both Tresiba and Lantus cause similar common side effects that include:
-
- Weight gain
- Hypoglycemia
- Injection site reactions
- Lipodystrophy
- Edema
- Allergic reactions
- Pruritus
- Rash
Let your doctor know if you experience symptoms related to these adverse reactions. They can adjust the treatment to minimize side effects and offer personalized lifestyle recommendations. Lifestyle shifts, such as eating a diabetes-friendly diet and exercising, can help maintain stable blood glucose.
7. Serious Risks
Using Tresiba or Lantus may elevate the risk of the following serious conditions:
-
- Severe high blood sugar levels
- Severe low blood sugar levels
- Hypersensitivity reactions, such as anaphylaxis
- Severe low potassium levels
- Fluid retention and heart failure
These serious side effects occur rarely, but communicate your concerns with your endocrinologist if you experience any signs of severe risks.
8. Tresiba vs. Lantus Weight Gain
Using insulin may lead to weight gain because of its anabolic effects, promoting fat and protein storage.
In clinical trials, patients with Type 1 diabetes treated with Tresiba gained an average of 1.8 kg, while those with Type 2 diabetes gained an average of 3 kg of body weight after 52 weeks.
On the other hand, weight gain in patients with Type 1 diabetes treated with Lantus ranged from 0.1-0.7 kg after 28 weeks of treatment.
Based on the findings of these separate studies, Lantus may result in less weight gain than Tresiba. However, results can vary from person to person and may be affected by their lifestyle. For instance, if you don’t exercise or eat healthy, you’ll likely gain weight, regardless of the brand of insulin you’re taking.
9. Cost of Tresiba vs. Lantus
In the U.S., the average cost of a Tresiba FlexTouch U-200 prefilled pen is $815, while a Lantus SoloStar Pen costs an estimated $550.
Insurance covering your diabetes supplies makes prescriptions more financially sustainable every month. If you don’t, manufacturer savings programs and patient assistance programs can reduce the prices if you meet certain criteria.
One way to make Tresiba and Lantus cost-effective is by buying from Canadian pharmacies and online prescription platforms like Buy Canadian Insulin, where diabetes supplies are more affordable.
For instance, you can purchase five Tresiba FlexTouch U-200 prefilled pens for only $179 instead of $815 and five Lantus Solostar U-100 pens for $177 instead of $550.
Why is it so much cheaper? In the U.S., big pharmacies determine prescription prices based on demand and supply. Insulins are an in-demand commodity, so they’re expensive — even overpriced sometimes.
In contrast, drug prices in Canada are regulated by a government agency, helping ensure insulin affordability. You can save up to 90% every month by purchasing prescriptions in Canada.
If you look at Tresiba cost vs. Lantus, Tresiba is slightly more expensive, which makes sense because it has a duration of action of up to 42 hours compared to Lantus’ 24-hour basal coverage.
If you have concerns about drug prices, your doctor may recommend cheaper yet effective alternatives.
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Can You Take Tresiba and Lantus Together?
Both Tresiba and Lantus are long-acting insulins — it’s not recommended and safe to use them together. Combining them increases the risk of extremely low blood sugar levels and other side effects.
Since they both serve as background insulin, using them together is unnecessary and potentially dangerous. You can only use one, alongside a short-acting insulin that your doctor will prescribe to manage mealtime spikes.
Alternatives and Biosimilars
If you’re looking for a Tresiba equivalent, several long-acting insulins provide basal coverage in controlling blood sugar levels and can serve as effective alternatives. They include:
Meanwhile, if you need a Lantus equivalent, your doctor may recommend its FDA-approved biosimilars, which include:
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- Semglee (insulin glargine-yfgn)
- Rezvoglar (insulin glargine-aglr)
These biosimilars are generic versions that are interchangeable with Lantus. They work the same way in controlling glycemic index but are more affordable. Your doctor may consider these options if you need to switch to a different insulin.
Which Is Better, Tresiba or Lantus?
In a nutshell, the better choice depends on your individual needs, blood sugar patterns, and lifestyle. Tresiba offers ultra-long-lasting coverage of up to 42 hours with more dosing flexibility. Lantus, on the other hand, provides basal coverage throughout the day and night and has a lower risk of overnight hypoglycemia because it’s peakless. It’s also generally more affordable.
Both are excellent options for basal insulin therapy and work well for managing fluctuating blood sugar levels. So, comparing Tresiba vs. Lantus and deciding which is better comes down to what you need and which is financially sustainable.
Proper dosing and following your doctor’s instructions are key to maintaining healthy blood sugar levels and preventing complications.
Frequently Asked Questions
Original Publish Date: 6/01/2022 – Updated 5/29/2025
