Lantus vs. Ozempic: 6 Differences to Consider

Lantus (insulin glargine) and Ozempic (semaglutide) are injectable medications that are used to lower blood glucose (sugar) levels in adults with Type 2 diabetes. They’re both considered highly effective at treating diabetes. But Lantus and Ozempic work differently, have different recommended dosages, and cause different side effects. They’re also used in some different ways.

Your prescriber may recommend adding Lantus, Ozempic, or both medications to your treatment plan. Knowing what sets them apart can help you understand the benefits that each medication offers. Below, we highlight and discuss seven key differences of Lantus versus Ozempic.

1. Lantus and Ozempic work differently

Lantus and Ozempic both treat diabetes by lowering blood glucose levels, but they achieve this goal in different ways. Additionally, Ozempic can help manage diabetes by promoting weight loss. And it has heart- and kidney-related benefits, too, which we’ll discuss more later.

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With Type 1 and Type 2 diabetes, the body is either not making enough insulin or is using insulin incorrectly. Insulin is necessary to move glucose from the blood into the cells, where it can be used for energy.

Lantus is a lab-made insulin medication. It’s a type of insulin called basal insulin, and it stays in the body for about 24 hours. It replaces, or adds to, the insulin your body would make if you didn’t have diabetes. 

Ozempic isn’t insulin. It mimics a type of incretin (gut hormone) called glucagon-like peptide-1 (GLP-1). Medications that do this are called GLP-1 agonists, and they have several effects on the body, including:

• Triggering the body to release more insulin after meals

• Reducing how much glucose the liver makes

• Slowing down the passage of food through the stomach, which slows down glucose absorption and leads to feeling full for longer

• Decreasing hunger by targeting certain areas in the brain

2. Lantus and Ozempic have different FDA-approved uses

Both Lantus and Ozempic are FDA-approved to treat Type 2 diabetes in adults. But they’re also approved for different uses. For example:

• Lantus is also approved to treat Type 1 diabetes in adults and children age 6 and older. Although Ozempic isn’t approved for Type 1 diabetes, some healthcare professionals may prescribe it off-label.

• Ozempic is approved to lower the risk of major adverse cardiovascular events (like heart attacks, strokes, and heart-related deaths) in people with Type 2 diabetes and heart disease.

Ozempic has also shown potential benefits for people with diabetes who have chronic kidney disease and heart failure. Some healthcare professionals may also prescribe Ozempic for prediabetes or weight loss, but these are off-label uses. 

3. Lantus and Ozempic have different recommended dosages

Lantus is usually a once-daily injection. Ozempic is only administered once a week, so it’s used less frequently than Lantus. You can inject Lantus and Ozempic subcutaneously (under the skin) in the stomach, upper arm, or upper thigh. And you can inject them at any time of day, without regard to meals. But with Lantus, you should aim to inject it at the same time every day.

Lantus comes as a multidose vial and a multidose injection pen (SoloStar). Both Lantus products contain 100 units per mL. Your exact Lantus dosage will depend on factors such as your blood glucose levels and your treatment goals. You may be prescribed Lantus alone or in combination with a shorter-acting insulin that’s injected at mealtime. Lantus may also be combined with other injectable or oral diabetes medications.

Ozempic comes as an injection pen that’s available in several doses. The starting Ozempic dosage is typically 0.25 mg once weekly for 4 weeks. After 4 weeks, your dosage will likely be increased to 0.5 mg once weekly. And it may be increased further from there. This approach gives your body time to adjust to Ozempic, and it helps you find a dosage that manages your blood glucose levels with as few side effects as possible.

4. It’s common to lose weight with Ozempic, but Lantus can make you gain weight

Lantus and Ozempic can affect body weight differently. Some people who take Lantus gain weight. Most people who take Ozempic lose weight. But as mentioned, Ozempic isn’t FDA approved for weight loss specifically. Another semaglutide product called Wegovy is, though. Ozempic dosages for diabetes are typically lower than Wegovy dosages for weight loss.

In a study comparing semaglutide to Lantus as an add-on medication to metformin for Type 2 diabetes, a commonly prescribed diabetes treatment, semaglutide was associated with weight loss, while Lantus was associated with weight gain. Specifically, participants taking 1 mg weekly lost about 11 lbs after 7 months of use. Participants taking Lantus on a daily basis gained about 3 lbs in the same period. 

In a clinical trial of Ozempic for Type 2 diabetes, people taking 2 mg once weekly lost an average of 15 lbs over 9 months. People taking a 1 mg once weekly lost slightly less (13 lbs).

In early clinical trials of Lantus, adults taking the insulin for Type 2 diabetes gained an average of 4 lbs in the first year of treatment.

5. Ozempic and Lantus have different side effects to consider

In general, Lantus and Ozempic cause different side effects. They can both cause irritation at the injection site, but this may be more likely with Lantus. Rotating injection sites with each dose can help prevent irritation and infection at the injection sites.

Hypoglycemia (low blood glucose) is also possible with both Lantus and Ozempic. But the risk is much higher with Lantus. Hypoglycemia isn’t common with Ozempic, but the risk goes up when it’s combined with other diabetes medications, like insulin or sulfonylureas.

In addition to hypoglycemia, other potential Lantus side effects include:

• Headaches

• Upper respiratory tract infections

• Low blood potassium

• Weight gain

• Lipodystrophy (thickening or pitting under the skin) 

The most common Ozempic side effects are gastrointestinal side effects like nausea, diarrhea, and stomach pain. These side effects often improve on their own over time. In the meantime, sticking to a diabetes-friendly diet that limits starchy, sugary, and fatty foods can help. And you can find other tips for managing nausea, diarrhea, or constipation caused by Ozempic through GoodRx Health. 

While rare, serious side effects have also been linked to Ozempic. These include:

• Pancreatitis

• Gallbladder problems

• Kidney problems

• Vision problems

• Thyroid tumors

• Slowed gastric emptying (gastroparesis)

Make sure your prescriber knows your full medical history, including if you have a family history of thyroid cancer or if you’re planning to become pregnant, before you start taking either medication. It’s recommended to stop taking Ozempic 2 months before trying to get pregnant. Meanwhile, insulin is the medication of choice for treating Type 1 and Type 2 diabetes during pregnancy.

6. Lantus has biosimilars and generic-like alternatives, but Ozempic is brand-name only

Ozempic is a brand-only medication. While Lantus is also a brand-name product, several products that are interchangeable with Lantus are also available. This includes the Lantus biosimilars Semglee (insulin glargine-yfgn) and Rezvoglar (insulin glargine-aglr). 

Biosimilars are medications that are highly similar to biologic medications, like Lantus. Biosimilars have the same benefits and risks as the original (reference) products they’re modeled after. And they’re considered interchangeable with the original products. Because of this, your pharmacist may be able to switch you from Lantus to one of its biosimilars without contacting your prescriber.

Semglee is a brand-name insulin product, but the manufacturer also makes an unbranded version (called insulin glargine-yfgn). Unbranded medications are similar to authorized generics, but for biologics.

Another insulin glargine medication, Basaglar, is similar to Lantus, but it’s not approved as a biosimilar. This means the two medications aren’t interchangeable. You’ll need a new prescription for Basaglar if your prescriber thinks it's the best option for you.

Can you take Lantus and Ozempic together?

Yes, Ozempic (and other GLP-1 agonists) may be combined with insulin to manage Type 2 diabetes. In fact, this combination can offset weight gain caused by insulin. If you’re prescribed both Lantus and Ozempic, they can be injected in the same general area as long as the sites aren’t right next to each other.

Whether you should take more than one diabetes medication at a time depends on your glucose levels and your overall treatment goals. Your prescriber can go through your options with you, as there are several medications that effectively treat diabetes. This includes oral and injectable options.

How to save on Lantus and Ozempic

There are various ways to save on Lantus and Ozempic. 

Here are some ways to save on Lantus:

• Save with GoodRx coupons. You may be able to save on the average retail price of Lantus SoloStar through GoodRx. At some pharmacies, the price for a pack of 5 Lantus pens may be as low as $98.89 with a free GoodRx coupon.

• Save with a copay savings card. If you have commercial insurance, you may be eligible to pay as little as $35 per month for Lantus SoloStar using a copay savings card from the manufacturer.

• Save with a patient assistance program. If you’re uninsured or underinsured, you may be eligible for Lantus’ patient assistance program, which offers the medication free of cost.

• Save with a biosimilar. Depending on your location and insurance status, a biosimilar version of Lantus may cost you less than the brand-name version. Your prescriber can tell you more about Semglee and Rezvoglar, if so.

Here are some ways to save on Ozempic:

• Save with a copay savings card. If you have commercial insurance, you may be eligible for a copay savings card from the manufacturer of Ozempic. This could lower your costs to as little as $25 per prescription.

• Save with a patient assistance program. If you’re uninsured or underinsured, you may be eligible for Ozempic’s patient assistance program, which offers the medication free of cost.

For more information, check out the GoodRx Health article on how to save on Ozempic.

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Written by:

Daphne Berryhill, RPh

Daphne Berryhill, RPh, has two decades of experience as a clinical pharmacist. She spent most of her career in the Chicago area practicing in-home infusion.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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