Wegovy and Mounjaro are two injectable prescription medications used to help lower blood sugar and A1c levels (a measure of glucose control over the previous 2 to 3 months) and help with weight loss. 

This guide will help you decide whether Wegovy or Mounjaro might be more appropriate for you.

Image of a Wegovy package and Mounjaro pens with a divider between them.

Key facts

  • Wegovy’s active ingredient is semaglutide, while Mounjaro’s active ingredient is tirzepatide. 
  • This distinction affects their metabolic actions and effectiveness in regulating appetite and blood sugar levels.
  • Wegovy is approved for obesity treatment and weight loss, while Mounjaro is approved for managing blood sugar in type 2 diabetes. 
  • Both medications reduce blood sugar and A1c levels and help with weight loss, and both also contribute to heart health.
  • They have different dosing schedules and are not interchangeable. 

What are the active ingredients in Wegovy versus Mounjaro?

The active ingredient in Wegovy is semaglutide, and the active ingredient in Mounjaro is tirzepatide. Their mechanisms of action differ slightly. 

Semaglutide mimics the glucose-like peptide (GLP)-1 hormones in the body, which play a role in decreasing appetite, slowing stomach emptying, reducing the release of glucose from the liver, and increasing insulin release. 

Tirzepatide has a dual function. It mimics both GLP-1 and GIP incretin hormones. 

While it shares GLP-1’s effects, the addition of GIP action enhances insulin release in response to high blood sugar and plays a role in fat metabolism. This enhances their ability to regulate appetite and prevent overeating. 

Wegovy and Mounjaro are similar drugs, but they cannot be combined or used at the same time. 

Why do people take Wegovy or Mounjaro?

Wegovy is FDA-approved for the treatment of obesity and to help with weight loss

It is approved for use in people with a body-mass index (BMI, a measure of weight relative to height) of 30 or higher or with a BMI of 27 or higher with one or more weight-related conditions (such as type 2 diabetes, high blood pressure, or high cholesterol).

Adolescents 12 years and older with a BMI at or greater than the 95th percentile for age and sex are also approved to take Wegovy.

Mounjaro is FDA-approved as a treatment to help adults with type 2 diabetes manage their blood sugar levels

They are both liquid, injectable medications that help lower blood sugar levels and A1c levels. They are taken subcutaneously (just under the skin) in areas such as the abdomen, thigh, or upper arm.

People dealing with insulin resistance and weight gain may be prescribed one of these medications. This is because, in addition to blood sugar management, they also slow digestion and suppress appetite. 

Finally, Wegovy and Mounjaro both lower the risk of heart attack and stroke. 

How are Wegovy and Mounjaro similar? 

The following are the effects of both medications: 

Lower blood sugar and A1c levels

Both have been proven to lower blood sugar and A1c levels. 

People who take the maximum dose of Mounjaro (15 milligrams [mg] per week) lower their A1c by an average of 2.3 percent

The STEP 2 trial looked at Wegovy’s effects on blood sugars and A1c levels in people who have type 2 diabetes. 

The researchers found that participants taking the medication not only lost weight but saw statistically significant improvements in their blood sugars and A1c levels.

These medications do this by increasing insulin secretion. 

This action stops the liver from releasing glucose into the bloodstream, helping to prevent low blood sugars while increasing insulin sensitivity

May cause weight loss 

In studies, both medicines cause weight loss in participants by suppressing appetite and inhibiting the liver from releasing glucose.

In one study, adult participants taking Wegovy lost 15 percent of their starting weight, on average. 

A separate study found that adolescents taking Wegovy lost 16 percent of their starting weight, on average. 

Mounjaro can also help with weight loss, although it is not FDA-approved as a standalone weight-loss drug. However, the FDA has approved a medication called Zepbound for this purpose. 

Zepbound is chemically identical to Mounjaro, containing the same active ingredient at the same strength, but it is marketed under a different name when used for weight-loss treatment.

In studies, Mounjaro helped people lose 12 to 15 pounds on a 5-mg weekly dose, between 15 and 21 pounds on a 10-mg weekly dose, and between 17 and 25 pounds on a 15-mg weekly dose.

There is no recommended dose to take for weight loss since these medications aren’t approved for this purpose by the FDA. 

(For Zepbound, the weight-loss version of Mounjaro, available doses are 2.5 mg, 5 mg, 10 mg, and 15 mg taken by injection once weekly, with 15 mg being the maximum dose.)

Talk with your doctor if you’re interested in losing weight. They can provide you with information on both pharmaceutical and lifestyle approaches that can help.

Protect heart health 

These medications both lower heart disease risk, which is important for people living with diabetes.

In studies, after 52 weeks, participants on the highest dose of Mounjaro (15 mg per week):

  • Lowered their total cholesterol by about 5.6 percent
  • Lowered their triglycerides by 22.5 percent 
  • Lowered their LDL (“bad”) cholesterol by 7.9 percent 
  • Lowered their VLDL cholesterol by 21.8 percent 
  • Increased their HDL (“good”) cholesterol by 10.8 percent 

Additionally, a meta-analysis (analysis of data from several clinical trials) from The Lancet found that GLP-1 receptor agonist medications, including semaglutide (the active ingredient in Wegovy), lowered cardiovascular risk. 

They even decreased the risk of death in people with diabetes and heart disease. 

The American Diabetes Association (ADA) recommends GLP-1 agonists for people who have type 2 diabetes and heart disease to lower the risk of heart attack and stroke. 

In addition to medications, eating a healthy diet and increasing the amount of physical activity you routinely get will go a long way to improving your heart health.

May cause adverse side effects

People experience similar side effects while taking either of these medications.

They may both cause nausea, vomiting, diarrhea, constipation, suppressed appetite, and low blood sugar (if you take insulin).

Side effects will be more severe when you first start taking the medication until your body adjusts to it. 

Contact your doctor if you’re experiencing debilitating side effects that are negatively affecting your quality of life. 

They can either lower your dose or find an alternative medication for you. 

Learn more in: Wegovy Side Effects: What You Need to Know and Mounjaro Side Effects: What You Need to Know.

They do not replace insulin 

While these medications lower blood sugar levels, they do not replace the need for insulin. 

They may, over time, reduce the amount of insulin you require, but they are not insulin nor are they replacements for insulin. 

Talk with your doctor if you’re experiencing frequent low blood sugar. 

They can help you recalibrate your insulin doses so you can experience fewer lows. 

They are taken once weekly 

Unlike other GLP-1 medications like Victoza, both Wegovy and Mounjaro are only taken once weekly. 

Never take more than one dose within a single week. 

They can be taken with or without food 

These medications do not cause acute low blood sugar and can be taken both with or without food. 

The important thing is that they’re taken on the same day each week (ideally around the same time, so you always remember to take your dose).

Sometimes people will pair taking their medication with a meal, like breakfast, but it is not required.

If you experience acute nausea immediately after taking your medication, you may want to eat something bland like oatmeal or toast to help. 

They may cause changes to your vision

These medications may cause or worsen diabetic retinopathy, especially when you first start taking them. 

Studies show that semaglutide (the active ingredient in Wegovy) is associated with the early worsening of diabetic retinopathy. 

Similarly, the active ingredient in Mounjaro (tirzepatide) can make diabetic retinopathy worse

Although this side effect does not occur in all people who take these medications, the drugs do come with an increased risk of vision changes and worsening vision. 

Talk with your doctor if you have early-stage diabetic retinopathy or are concerned that taking Wegovy or Mounjaro may impact your eye health. 

How are Wegovy and Mounjaro different? 

Wegovy and Moujaro, while being remarkably similar, are different drugs. 

The following are the ways in which these medications differ: 

They have different doses

The doses for Wegovy are the following: 

  • New to treatment: 0.25 mg once per week for the first four weeks.
  • Ongoing treatment: 0.5 mg once per week starting on week five. If your doctor thinks you require more, there are doses available in 1-mg, 1.7-mg, and 2.4-mg pens. 

Read more: Wegovy Dosage Guide: How Much Should You Take?

The doses for Mounjaro are the following:

  • New to treatment: 2.5 mg once per week for the first four weeks.
  • Ongoing treatment: 5 mg once per week starting on week five. If your doctor thinks you require more, there are doses available in 7.5-mg, 10-mg, 12.5-mg, and 15-mg pens. Since the active ingredients are different, these medications are not interchangeable. 

Read more: Mounjaro Dosing Guide: How Much Should You Take?

Since the active ingredients are different, these doses are not interchangeable and it can be very dangerous if you attempt to use them in this manner. 

They have different active ingredients

The active ingredient in Wegovy is semaglutide (the same as in Ozempic), and the active ingredient in Mounjaro is tirzepatide. 

Talk with your doctor if you are allergic to one or the other’s active ingredient so that they can prescribe you an alternative. 

They are FDA-approved for different reasons 

Wegovy is intended to be used as a weight-loss and/or weight-maintenance drug. It is not an approved medication for the treatment of type 2 diabetes. 

However, many people who take Wegovy for weight loss or weight maintenance can also experience the improved blood sugar effects of taking the medication. 

Mounjaro, on the other hand, is an FDA-approved medication for the management of blood sugar levels in people with type 2 diabetes. 

It also helps with weight loss, even though it is not FDA-approved as a weight-loss drug. (As noted above, a version of the medicine known as Zepbound has been approved by the FDA for weight loss.)

Since many people with type 2 diabetes also struggle with their weight, taking Mounjaro for improved blood sugar management can also help with weight loss. 

Can I switch between the two drugs? 

In some cases, yes. 

As long as you do not have any allergies to the ingredients of the other medication, it may be possible.

If you’re experiencing severe adverse side effects on one drug, you may wish to try another to see if your body will adjust better to it. 

You’re more likely to be able to switch between these two medications if you fall under the eligibility criteria for both. Namely, obesity and type 2 diabetes. 

If you only have type 2 diabetes, your insurance may only cover Mounjaro for you. 

Alternately, if you have obesity but not type 2 diabetes, you may only qualify for Wegovy. 

Only switch medications under the guidance of your doctor. 

The dosing is completely different between the two medications and overdosing on these medications can cause severe side effects.

These side effects include nausea, vomiting, and low blood sugar levels — which can be fatal if not treated quickly. 

Can I get off my other diabetes medications if I lose enough weight on Wegovy or Mounjaro?

This may be possible, but it is not probable. 

Losing weight can help improve both insulin resistance and blood sugar levels. Sometimes this makes your insulin or other diabetes medications unnecessary.

However, neither Wegovy nor Mounjaro will cure diabetes. 

You may be able to lower your insulin needs or stop taking insulin completely if you’ve lost a significant amount of weight and your blood sugar levels are very well managed.

This will only apply to people who have type 2 diabetes, as people with type 1 diabetes must take insulin for life. 

Check with your doctor if you have questions about taking your other diabetes medications while on Wegovy or Mounjaro. 

Is Wegovy better than Mounjaro?

Individual responses to these medicines vary, and what is better for one person may not be better for another.

Additionally, because they are approved for different purposes, it is challenging to directly compare their effectiveness.

In terms of weight loss alone, recent research has suggested that people taking the active ingredient in Mounjaro are more likely to lose 5 percent, 10 percent, or 15 percent of their weight and to have a larger reduction in their weight at 3, 6, and 12 months compared to those taking the active ingredient in Wegovy.

How much do Wegovy and Mounjaro cost?

The cost of Wegovy and Mounjaro varies depending on your insurance coverage and specific plan details. 

To determine your specific co-pay or out-of-pocket costs, consult your prescription or medical card and use the Wegovy or Mounjaro coverage and co-pay calculators.

If you have questions regarding coverage or co-pay costs for Wegovy, you can contact Novo Nordisk customer support at 1-888-693-4883. For Mounjaro, Eli Lilly offers customer support at 1-800-545-5979.

For those who qualify, both Novo Nordisk and Eli Lilly offer Patient Assistance Programs (PAP) that may provide free medication. 

To learn more about these programs and see if you are eligible, contact Novo Nordisk’s PAP toll-free at 1-866-310-7549 or Eli Lilly’s PAP at 1-800-545-6962.

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