Tresiba (insulin degludec) and Lantus (insulin glargine) are brand-name prescription medications. They’re approved by the Food and Drug Administration (FDA) to treat type 1 and type 2 diabetes in adults and certain children.
This article explains the main ways that Tresiba and Lantus are alike and different. If you’re considering using one of these insulins, discuss this information with your doctor. They can help determine whether Tresiba or Lantus may be better for you.
Note: For more comprehensive information about these drugs, you can refer to our Tresiba and Lantus articles.
Key differences between Tresiba and Lantus
These are a few of the main differences between Tresiba and Lantus:
- Strengths: Tresiba and Lantus are both available in a strength of U-100. This means each drug comes in a form that contains 100 units of insulin per milliliter (mL) of solution. Tresiba is also available in a strength of U-200, which means it contains 200 units per mL of solution. (See “Dosages, forms, and administration” below.)
- Use in children: Tresiba is approved for use in certain children with either type 1 or type 2 diabetes. Lantus is approved for use in certain children with type 1 diabetes. (See “Uses of Tresiba vs. Lantus” below.)
Below are answers to some common questions about Tresiba and Lantus.
What’s the dose conversion when switching between Tresiba and Lantus?
Your doctor will determine the dose conversion if they recommend that you switch between Tresiba and Lantus.
If you’d like to switch from Tresiba to Lantus or vice versa, talk with your doctor. They’ll advise you on whether it’s possible for you to switch.
If your doctor agrees with a switch, they can instruct you on how to adjust your dosage of Tresiba or Lantus. It’s important that you do not change your treatment plan unless your doctor recommends it.
For details about dosages for these insulins, see our dosage articles about Tresiba and Lantus. You can also talk with your doctor or pharmacist.
Is weight gain a side effect of Tresiba and Lantus?
Yes, weight gain is a common side effect of all insulins, including Tresiba and Lantus. These drugs are both long-acting insulins (also called basal insulins). Long-acting insulins help manage blood sugar overnight and between meals.
Insulin helps your body move sugar from your blood to your cells. Some of this sugar is stored as fat, and this can lead to weight gain.
Weight gain with Tresiba and Lantus may also be due to a type of swelling called peripheral edema. This is a possible side effect of both drugs.
For details about weight gain with these medications and how to manage it, see our side effect articles about Tresiba and Lantus. You can also talk with your doctor or pharmacist.
How do Tresiba and Lantus compare with the diabetes drugs Levemir and Toujeo?
Below are a few ways Tresiba and Lantus compare with the diabetes drugs Levemir and Toujeo.
| Tresiba | Lantus | Levemir | Toujeo | |
| Active ingredient | insulin degludec | insulin glargine (see note below) | insulin detemir | insulin glargine (see note below) |
| Drug class | long-acting insulin* | long-acting insulin* | long-acting insulin* | long-acting insulin* |
| Uses in adults | type 1 and type 2 diabetes in adults | type 1 and type 2 diabetes in adults | type 1 and type 2 diabetes in adults | type 1 and type 2 diabetes in adults |
| Uses in children | type 1 and type 2 diabetes in certain children | type 1 diabetes in certain children | type 1 diabetes in certain children | type 1 and type 2 diabetes in certain children |
* Long-acting insulins (also called basal insulins) act slowly. They’re used to help manage blood sugar overnight and between meals.
To learn more about how Tresiba and Lantus compare with Levemir and Toujeo, talk with your doctor.
Note: Both Lantus and Toujeo contain insulin glargine as an active ingredient. However, Toujeo is more concentrated than Lantus. This means that compared with Lantus, Toujeo has more units of insulin per milliliter (mL) of solution. So you might be able to use a smaller volume of Toujeo than Lantus.
Switching between Tresiba and Lantus is possible.
If you’d like to know more about switching between Tresiba and Lantus, talk with your doctor. They can give you additional details and help determine the best course of action for your personal situation. Even if two drugs treat the same condition or are in the same drug class, your body can still respond differently.
It’s important that you do not stop, start, or switch any of your drug treatments without your doctor’s recommendation.
Here’s a quick look at the dosage and administration of Tresiba and Lantus for the conditions both drugs treat. In the tables below, milliliters and kilograms are abbreviated as mL and kg.
Dosage for type 1 diabetes
Below are the dosages of Tresiba and Lantus for type 1 diabetes in adults.
| Tresiba for type 1 diabetes in adults | Lantus for type 1 diabetes in adults | |
| Forms | • solution in a 10-mL multiple-use vial, given by subcutaneous injection • solution in a 3-mL FlexTouch pen, given by subcutaneous injection | • solution in a 10-mL multiple-use vial, given by subcutaneous injection • solution in a 3-mL SoloStar pen, given by subcutaneous injection |
| Strengths | • Tresiba vial: U-100 (100 units of insulin per mL) • Tresiba FlexTouch pen: U-100 and U-200 (200 units of insulin per mL) | • Lantus vial: U-100 • Lantus SoloStar pen: U-100 |
| Dose | about one-third to one-half of your total daily insulin dosage | about one-third of your total daily insulin dosage |
| Frequency | once per day | once per day |
| Given by | self (see below) | self (see below) |
Your doctor will tell you the exact dosage of Tresiba or Lantus that’s recommended for you.
A healthcare professional will show you or a caregiver how to inject Tresiba or Lantus. Both drugs are typically injected under the skin of your abdomen, thigh, or upper arm.
Dosage for type 2 diabetes
Below are the dosages of Tresiba and Lantus for type 2 diabetes in adults.
| Tresiba for type 2 diabetes in adults | Lantus for type 2 diabetes in adults | |
| Forms | • solution in a 10-mL multiple-use vial, given by subcutaneous injection • solution in a 3-mL FlexTouch pen, given by subcutaneous injection | • solution in a 10-mL multiple-use vial, given by subcutaneous injection • solution in a 3-mL SoloStar pen, given by subcutaneous injection |
| Strengths | • Tresiba vial: U-100 (100 units of insulin per mL) • Tresiba FlexTouch pen: U-100 and U-200 (200 units of insulin per mL) | • Lantus vial: U-100 • Lantus SoloStar pen: U-100 |
| Dose | 10 units | either: • 10 units or • 0.2 units per kg of body weight* |
| Frequency | once per day | once per day |
| Given by | self (see below) | self (see below) |
* One kg is about 2.2 pounds (lb). As an example Lantus dosage, a person weighing 75 kg (about 165 lb) would use 15 units of Lantus each day.
Your doctor will tell you the exact dosage of Tresiba or Lantus that’s recommended for you.
A healthcare professional will show you or a caregiver how to inject Tresiba or Lantus. Both drugs are typically injected under the skin of your abdomen, thigh, or upper arm.
Children’s dosage
Tresiba and Lantus are both approved to treat type 1 diabetes in children ages 6 years and older. (Tresiba is also approved to treat the condition in children ages 1 to 6 years. In addition, Tresiba is approved to treat type 2 diabetes in children ages 1 year and older.)
Dosage for type 1 diabetes in children
Below are the dosages of Tresiba and Lantus for type 1 diabetes in children ages 6 years and older.
| Tresiba for type 1 diabetes in children | Lantus for type 1 diabetes in children | |
| Forms | • solution in a 10-mL multiple-use vial, given by subcutaneous injection • solution in a 3-mL FlexTouch pen, given by subcutaneous injection | • solution in a 10-mL multiple-use vial, given by subcutaneous injection • solution in a 3-mL SoloStar pen, given by subcutaneous injection |
| Strengths | • Tresiba vial: U-100 (100 units of insulin per mL) • Tresiba FlexTouch pen: U-100 and U-200 (200 units of insulin per mL) | • Lantus vial: U-100 • Lantus SoloStar pen: U-100 |
| Dose | about one-third to one-half of their total daily insulin dosage | about one-third of their total daily insulin dosage |
| Frequency | once per day | once per day |
| Given by | adult (see below) | adult (see below) |
Your child’s doctor will tell you the exact dosage of Tresiba or Lantus that’s recommended for your child.
A healthcare professional will show you or a caregiver how to inject Tresiba or Lantus. Both drugs are typically injected under the skin of the abdomen, thigh, or upper arm.
Note: For more information about dosage, see our dosage articles about Tresiba and Lantus.
How much Tresiba or Lantus costs depends on the treatment plan your doctor prescribes, your insurance plan, and your pharmacy. You can visit Optum Perks for price estimates of Tresiba and Lantus.
Both Tresiba and Lantus are brand-name biologic drugs. Lantus also comes in two biosimilar forms:
- Semglee (insulin glargine-yfgn)
- Rezvoglar (insulin glargine-aglr)
The reason “-yfgn” and “-aglr” appear at the end of the drug name is to show that the drug is distinct from other biosimilar versions.
Brand-name medications are often more expensive than biosimilars. To learn about biosimilar drugs, see “Generics or biosimilars: Tresiba and Lantus” below. You can also talk with your doctor or pharmacist.
Tresiba and Lantus both contain a long-acting insulin. And they’re both used to treat type 1 and type 2 diabetes. Tresiba and Lantus can cause some of the same side effects, as well as some different ones. Some of the side effects reported in clinical trials of these drugs are mentioned below.
For more details about side effects of these drugs, see our side effect articles about Tresiba and Lantus. You can also refer to the Tresiba prescribing information and Lantus prescribing information.
Mild side effects
The following table lists some of the more commonly reported mild side effects of Tresiba and Lantus. The table may also include mild side effects that are less common but that you might have concerns about in some cases.
| Mild side effects | Tresiba | Lantus |
| injection site reactions, such as pain, swelling, itching, or discoloration around the injection area | ✓ | ✓ |
| upper respiratory infections, such as the common cold | ✓ | ✓ |
| headache | ✓ | ✓ |
| edema (swelling), typically in the legs, ankles, or feet | ✓ | ✓ |
| weight gain | ✓ | ✓ |
| mildly low blood sugar level | ✓ | ✓ |
| diarrhea | ✓ | ✓ |
| pain in your joints, arms, back, or legs | ✓ | |
| mild allergic reaction | ✓ | ✓* |
* An allergic reaction is possible after using Lantus, but it’s not clear whether this side effect occurred in clinical trials.
These side effects may be temporary, lasting a few days to weeks. If the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.
Serious side effects
The following table lists the reported serious side effects of Tresiba and Lantus.
| Serious side effects | Tresiba | Lantus |
| low blood potassium level | ✓ | ✓ |
| severely low blood sugar level | ✓ | ✓ |
| severe allergic reaction | ✓ | ✓* |
* An allergic reaction is possible after using Lantus, but it’s not clear whether this side effect occurred in clinical trials.
If you have serious side effects while using Tresiba or Lantus, call your doctor immediately. If the side effects feel life threatening or you believe you’re having a medical emergency, call 911 or your local emergency number right away.
Here’s information about the generic and biosimilar status for Tresiba and Lantus, as well as details about their active ingredients.
| Tresiba | Lantus | |
| Generic available | no (see note below) | no |
| Biosimilar available | no (see note below) | yes |
| Active ingredients | insulin degludec | insulin glargine |
| Drug class | long-acting insulin* | long-acting insulin* |
* Long-acting insulins (also called basal insulins) act slowly. They’re used to help manage blood sugar overnight and between meals.
Note: Tresiba and Lantus are biologics, meaning they’re made from parts of living cells. Biologics differ from traditional drugs, which are made from chemicals. Generics are exact copies of the active drug in traditional brand-name medications. However, biologics cannot be copied exactly. So instead of generics, biologics have biosimilars.
The Food and Drug Administration (FDA) has approved Tresiba and Lantus to treat the following:
- Both Tresiba and Lantus are FDA-approved to treat:
- type 1 and type 2 diabetes in adults
Tresiba or Lantus and children
The FDA has approved Tresiba and Lantus to treat the following conditions in children.
- Tresiba is FDA-approved to treat:
- type 1 and type 2 diabetes in children ages 1 year and older
- Lantus is FDA-approved to treat:
- type 1 diabetes in children ages 6 years and older
Note: For more information about the drugs’ uses, see our articles about Tresiba and Lantus.
Keep reading to learn more about the effectiveness of Tresiba and Lantus.
Review of clinical trials. Below is a brief look at whether Tresiba or Lantus was found to be more effective for treating type 1 and type 2 diabetes.
Separate clinical trials of Tresiba and Lantus were compared in a larger review of trials. The results of this review found both drugs to be similarly effective for treating type 1 and type 2 diabetes. However, this review found that Tresiba may be less likely than Lantus to cause low blood sugar as a side effect.
Keep in mind that reviews of trial results may not apply to your individual health situation. To learn whether Tresiba or Lantus may be right for you, talk with your doctor.
Prescribing information. For information about how effective these drugs were in clinical trials, see the prescribing information for Tresiba and Lantus. Keep in mind that trial results may not apply to your individual health situation.
Treatment guidelines. Another way to determine whether a drug is considered effective is to look at treatment guidelines. When an organization includes certain drugs in treatment guidelines, this means that research has shown the drug to be safe and effective.
Long-acting insulins (such as Tresiba and Lantus) are recommended treatment options for people with diabetes in guidelines from the American Diabetes Association.
Tresiba and Lantus may not be right for you if you have certain medical conditions or other factors that affect your health. The drugs share some of the same precautions, but they also have different ones. Some of these precautions are mentioned below.
If any of the following medical conditions or other health factors are relevant to you, talk with your doctor before using Tresiba or Lantus.
| Precaution | Tresiba | Lantus |
| if you’ve had an allergic reaction to either drug or any of its ingredients | ✓ | ✓ |
| if you’re pregnant or thinking about becoming pregnant | ✓ | ✓ |
| if you’re breastfeeding or thinking about breastfeeding | ✓ | ✓ |
| if you have a low blood potassium level | ✓ | ✓ |
| if you have a low blood sugar level | ✓ | ✓ |
| if you have heart failure and take a type of diabetes drug called a thiazolidinedione (TZD)* | ✓ | ✓ |
| if you have liver or kidney disease | ✓ | ✓ |
* Examples of TZDs include Actos (pioglitazone) and Avandia (rosiglitazone).
Note: For more comprehensive information about these two drugs, you can refer to our Tresiba and Lantus articles.
Some key points to remember when comparing Tresiba and Lantus include:
- Both Tresiba and Lantus can be used to treat type 1 and type 2 diabetes in adults, and type 1 diabetes in certain children. In addition, Tresiba can be used to treat type 2 diabetes in certain children.
- Both Tresiba and Lantus are available in a strength known as U-100. This means each medication comes in a form that has 100 units of insulin per milliliter (mL) of solution. Tresiba also comes in a form that has 200 units per mL of solution (U-200).
If you’d like to learn more about Tresiba or Lantus, talk with your doctor or pharmacist. They can help answer any questions you have about similarities and differences between the drugs. They can also help determine whether one drug or the other might work well for you.
Note: For more information about diabetes, see our diabetes hub.
Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.