Insulin is a hormone that is made inside an organ called the pancreas. Every time we eat, cells within our pancreas release insulin that help our body use or store our blood glucose. People with type 1 or type 2 diabetes may need insulin therapy to make up for dysfunction in the use or production of insulin. People with type one diabetes have a pancreas that cannot make insulin any longer. In type 2 diabetes people’s pancreas still makes insulin, but the bodies do not respond to it well.

How does insulin work?

Long-acting insulin

Long-acting insulin mimics the pancreas’s natural ability to maintain steady blood glucose throughout each day. Therefore, using long-acting insulin can help people with diabetes better control their blood glucose. While there are many types of short-acting insulin, there are only a couple long-acting preparations.

Types of intermediate and long-acting insulin

NPH (Humulin N, Novolin N)Degludec (Tresiba)
Glargine (Lantus)
Detemir (Levemir)

Key differences

Onset: 2-4 hoursOnset: several hours after injection
Peak: 4-12 hoursPeak: None
Duration: 12-18 hoursDuration: up to 24 hours


Lantus is a long-acting insulin that is used to treat type 2 diabetes in adults and type 1 diabetes in children over the age of six. Lantus is manufactured by Sanofi and has been on the market since 2000. Lantus has been scientifically proven to lower hemoglobin A1C, a measure of blood sugar control. Once it is open it can last for four weeks outside of the refrigerator.

Lantus Vial 100 Units / mL

100u/mL/10mL – 1 Vial


Tresiba is a long-acting insulin that controls blood sugar for 24 hours. It is approved for use in anyone over the age of one with type 1 or type 2 diabetes. Tresiba has been proven to reduce the hemoglobin A1C level and provide slow and steady blood glucose control like the pancreas. Tresiba is manufactured by NovoNordisk and has been on the market since 2015. Tresiba allows adults to vary the daily dosing interval by 8 to 40 hours, providing around-the-clock glycemic control. Tresiba is currently the only insulin approved for use in children as young as one.

Tresiba FlexTouch 200 Insulin Pens

 200 Units / mL – 3 pens


Lantus can be used in adults and children ages 6 and older for type one or type two diabetes. Tresiba can be used in adults and children aged 1 and older for type one and type 2 diabetes. Both are considered long-acting insulin with no identifiable peak; therefore their use is most consistent with the pancreas’s basal production of insulin throughout the day.


Administered by either the SoloStar injection pen or a vial and a syringe it can be used once a day. It is recommended to administer it at the same time every day. Lantus can continue to work throughout the day and the night, from 12-24 hours. Lantus is indicated to improve glycemic control in adults and in pediatric patients with type one diabetes over the age of six.


Tresiba can be taken by injection once a day and is available in a flex pen or a vial and syringe. It is recommended you use Tresiba at the same time every day, but if an adult misses a dose, they can take their next dose as soon as they remember. Tresiba offers a little more dosing flexibility compared to other long-acting insulin preparations. If a dose is missed, just ensure that eight hours are between each dose.

Key differences between Lantus and Tresiba



Must be 6 years or olderMust be 1 year or older
Insulin glargineInsulin degludec
Manufactured by SanofiManufactured by NovoNordisk
Type 2 diabetes in adults, type one over 6Type 1 or type 2 diabetes
Lasts up to 24 hoursLasts up to 42 hours
Must be taken at the same time each dayAdministration times can vary

In addition to the duration of action, chemical make-up, and age range in which users can begin using this medicaiton, there are a few other key differences. While any preparation of insulin has a risk of hypoglycemia or low blood sugar, Tresiba has been shown to be less likely to cause these events. Cost is also a likely factor when considering differences in your diabetes medications. Lantus is generally cheaper than Tresiba.

Side effects

Both Lantus and Tresiba

The side effects are very similar for both Tresiba and Lantus. Some side effects can be an emergency, while others just require close monitoring and a discussion with your doctor.

Common side effects

Emergency side effects

Swelling of the hands and feetHypoglycemia
Weight gainTrouble breathing
Injection site irritationSwelling of the face, lips, and mouth
Skin pitting at the injection siteRash all over the body
Skin thickening at the injection siteExtreme dizziness or confusion
Low blood potassium levels

Hypoglycemia. The most common side effect of any insulin is hypoglycemia or low blood sugar which can be very serious and even life-threatening. Commonly people will experience symptoms prior to an episode of hypoglycemia which includes:

  • sweating
  • fast heartbeat
  • shakiness
  • blurred vision

To remain safe while on insulin therapy, it is essential that you track your blood sugar and know what to do in the event of a hypoglycemia event. If you experience any of the above symptoms, you should immediately check your blood sugar levels, and eat a sugary snack.


Do not mix either Lantus or Tresiba with any other insulins or solutions. Discuss all your other medications with your doctor to ensure none of the medications you are taking could potentially interact with your long-acting insulin. You should also avoid alcohol while using long-acting insulins as they can complicate the detection of hypoglycemic events.

You should avoid taking TZDs while using Tresiba as it can cause heart failure in those who do not already have heart failure. Additionally, if you become more active, drastically change your diet, or become sick, you may need to discuss dose adjustments with your doctor.

Do not share needles or insulin pens or syringes with anyone else. You should not reuse your own needles, disposing of them after each use. To prevent infections, you should change and rotate your injection sites. This can also reduce your risk of getting pitted or thickened skin. You should avoid reusing the same injection sites for your insulin.


Your dosage can vary widely based on your own insulin needs. Your doctor will evaluate your laboratory values in conjunction with your current medication regimen to determine what dosing is the best option for you.



Lantus comes in two preparations, a prefilled pen, or a vial. Options for administration include vial and syringes or the SoloStar Lantus pen. Lantus is most commonly available in a 100 unit per milliliter vial which is a total of 10 milliliters. The prefilled pen comes as 100 units per milliliter in a 3-milliliter pen.


Tresiba also comes in two preparations, like Lantus. Tresiba can be administered from a vial with syringes, or the FlexTouch pen. The vial comes in two concentrations, 100 or 200 units per milliliter. The Tresiba FlexTouch pen comes as 100 units per milliliter in a 3-milliliter prefilled syringe. Once opened, the FlexTouch pen can last up to eight weeks of use if it is refrigerated or kept at room temperature.

Frequently Asked Questions


How do I take Lantus?

Lantus is an injection that will be administered under this skin it’s called a subcutaneous injection which can either be administered via the Lantus SoloStar pen or with a vial and a syringe.

Can Lantus cause weight gain?

Weight gain can occur with any insulin therapy which includes Lantus following a healthy diet and exercise program can help you with weight control

Are there any side effects with Lantus?

The most common side effect of any insulin including Lantus is low blood sugar which can be serious or life-threatening. other serious reactions include allergic reactions. seek medical attention immediately if you develop a rash over your body trouble breathing sweating swelling of your tongue throat or face shortness of breath or extreme drowsiness or confusion.

Can I mix Lantus with other insulin?

No, you should not mix Lantus with any other insulin or other solutions it may not work as intended and you could lose blood sugar control

I take mealtime insulin will I need to change my dose while I’m on Lantus?

You should discuss with your doctor what if any adjustments you should make to your insulin regimen when you add Lantus

Is there a generic version of Lantus?

No. There is only one Lantus preparation. There are other biosimilars on the market, although they may have a slightly different action than Lantus. Talk with your doctor to determine what long-acting insulin may be best for you.


What is Tresiba?

Tresiba is a long-acting insulin that is used to control high blood sugar in adults and children as young as one year of age with diabetes.

Do I have to take Tresiba at the same time every day?

Adults can take Tresiba at any time of the day. It is up to you to decide which time and place work best for you. Children must take their dose at the same time every day. Adults who miss or delay a dose should take their dose as soon as they remember and then continue with their regular dose schedule. You should ensure that there are at least eight hours between your doses. If a child misses a dose, you should call their health care provider and monitor blood sugar more closely until the next scheduled dose.

Does Tresiba interact with other drugs?

It is important to discuss any medications you take with your health care provider including any prescription and over-the-counter drugs. Your dose of Tresiba may be changed if you take other medications, and doses of other medicines can be changed as well. Heart failure can occur in some people who take TZDs. It can develop even if you’ve never had heart problems before if you already have heart problems it can worsen them so tell your health care provider if you have any new or worsening symptoms of heart failure like shortness of breath tiredness or swelling of your ankles and feet.

Can Tresiba be used with other diabetes medications?

It can be used in combination with diabetes pills or short-acting insulin.

How do I take Tresiba?

Tresiba is administered by subcutaneous injection once a day. you should discuss with your doctor how to take Tresiba based on your individual insulin needs. if you believe you may need to change your dosing because of new medicines stress changing your diet or exercise you need to consult with your health care provider. do not make any changes to your dose or the type of insulin that you’re using unless your health care provider tells you to

Can children take Tresiba?

Tresiba is the only long-acting insulin that’s approved for both type 1 and type 2 diabetes in children as young as one-year-old.

How is Tresiba dispensed by a pharmacy?

Tresiba is available in three preparations:

100 units/milliliter200 units/milliliter100 units/milliliter
FlexTouch (5 pens/pack)FlexTouch (3 pens/pack)Multi-dose 10mL vial

What should I avoid while taking Tresiba?

You shouldn’t drive or operate heavy machinery until you know how Tresiba affects you.  you also shouldn’t drink alcohol or use prescription or over the counter medications that may alcohol

What are the possible side effects of using Tresiba?

The most serious and potentially life-threatening side effects include low blood sugar, low blood potassium, and heart failure.