Wegovy vs. Mounjaro: which is best for weight loss?

When looking into weight loss treatments, many people find themselves comparing Wegovy (semaglutide) and Mounjaro (tirzepatide). Both medications share some similarities and can both be effective tools for weight loss, but they are two distinct medications with some key differences. Wegovy is approved for weight loss, while Mounjaro is FDA-approved for type 2 diabetes. Tirzepatide, the active ingredient in Mounjaro, is FDA-approved for chronic weight management under the brand name Zepbound. 

This article provides an in-depth look at Wegovy vs. Mounjaro — including side effects, costs, and effectiveness — to help readers determine which medication may be the best fit.

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Wegovy and Mounjaro are both injectable medications called glucagon-like peptide-1 receptor agonists, or GLP-1s. While similar, they have some key differences, including their active ingredients, approved indications, costs, and mechanism of action.

Here is a quick overview of key facts about each medication.

What is Wegovy? 

Wegovy (semaglutide) is a prescription weight loss medication first approved by the US Food and Drug Administration (FDA) in 2021. It is one of the most widely used GLP-1 medications for chronic weight management in adults and adolescents, and it is available in two forms: an injection and a pill.

• Drug class: Wegovy is a glucagon-like peptide-1 (GLP-1) receptor agonist. Its active ingredient is semaglutide.

• Indication(s): Wegovy is FDA-approved for chronic weight management in adults with obesity or adults with overweight who have a related health condition, such as high blood pressure, type 2 diabetes, or high cholesterol. The injection is also approved for weight management in adolescents 12 and older with obesity. Both the injection and pill are approved to reduce the risk of major cardiovascular events — such as heart attack and stroke — in adults with cardiovascular disease who have obesity or overweight. The Wegovy pill is approved for adults only.

• Form and frequency: The Wegovy injection comes in a prefilled, single-dose pen administered subcutaneously once weekly, on the same day each week. The Wegovy pill is taken once daily in the morning, on an empty stomach, at least 30 minutes before eating, drinking anything other than plain water, or taking other medications.

• Dosing: Wegovy comes in five dose strengths: 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, and 2.4 mg. The dosing schedule for Wegovy typically starts at the lowest dose (0.25 mg). A healthcare provider may then gradually increase the dose every four weeks, depending on tolerability. For patients who have tolerated the 2.4 mg injection for at least four weeks and need additional weight loss support, a higher-dose option — Wegovy HD (7.2 mg) — was FDA-approved in March 2026. The Wegovy pill comes in four strengths: 1.5 mg, 4 mg, 9 mg, and 25 mg, with a starting dose of 1.5 mg once daily and a maintenance dose of 25 mg once daily.

• Mechanism of action: Wegovy works by mimicking GLP-1, a hormone produced in the intestines. GLP-1 may help promote weight loss by suppressing appetite and slowing digestion to promote a longer feeling of fullness.

What is Mounjaro?

Mounjaro (tirzepatide) is a prescription medication that is FDA-approved to treat type 2 diabetes in adults and children 10 and older.  It is not FDA-approved for weight loss.

• Drug class: Mounjaro is a dual-action glucagon-like peptide-1 (GLP-1)/glucose-dependent insulinotropic polypeptide (GIP) receptor agonist. It contains the active ingredient tirzepatide. 

• Indication(s): Mounjaro is FDA-approved for type 2 diabetes. In 2023, the FDA approved tirzepatide for weight loss under the brand name Zepbound.

• Form and frequency: Mounjaro comes in a single-dose pen administered subcutaneously once per week, on the same day each week.

• Dosing: Mounjaro comes in six dose strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. The dosing schedule for Mounjaro typically starts at the lowest dose of 2.5 mg and may be gradually increased every four weeks until a maintenance dose is reached. A healthcare provider will monitor progress and side effects to determine the appropriate maintenance dose. 

• Mechanism of action: Mounjaro uses a dual-action mechanism to target both GLP-1 and GIP receptors. GLP-1 and GIP are naturally occurring gut hormones involved in blood sugar regulation, appetite signaling, and other metabolic processes. 

Wegovy and Mounjaro work in similar but slightly different ways. Both medications mimic a naturally occurring gut hormone called GLP-1; however, because Mounjaro is a dual-action medication, it mimics GLP-1 as well as another hormone called GIP. 

GLP-1 and GIP are both incretin hormones secreted by the gut after eating. They serve a variety of functions that may help regulate blood glucose (sugar) and promote weight loss, including:

• Stimulating insulin release. GLP-1 stimulates the release of insulin in the pancreas after eating, especially when blood sugar is elevated.. Insulin is a hormone that helps transport sugar from the bloodstream into cells, where it is converted into energy. By triggering insulin production, medications such as Wegovy and Mounjaro may help regulate blood sugar levels.

• Reducing glucagon secretion. Glucagon is a hormone produced in the pancreas that prevents blood sugar from dropping too low. It triggers the liver to release glucose and raise blood sugar levels, which may contribute to high blood sugar in people with type 2 diabetes.

• Suppressing appetite. Wegovy activates GLP-1 receptors, while Mounjaro activates both GIP and GLP-1 receptors in the brain to reduce hunger cues. People taking these medications also report less “food noise,” a colloquial term that describes persistent and intrusive thoughts about food. 

• Slowing gastric emptying. GLP-1 medications also slow how quickly food moves from the stomach to the small intestine. This may promote faster satiety and greater satisfaction between meals.

Mounjaro's dual-action mechanism may enhance these effects, which could lead to better blood sugar control and more significant weight loss results.

Mounjaro and Wegovy both demonstrated positive weight loss results in clinical trials. 

Even though Mounjaro is not specifically indicated for weight management,tirzepatide is approved for weight loss under the brand name Zepbound. Research, including a head-to-head trial, suggests tirzepatide may lead to greater average weight loss than semaglutide.  

Tirzepatide acts on two hormone pathways (GLP-1 and GIP) rather than just one which might help explain why tirzepatide has produced greater average weight loss in some studies. Wegovy and Mounjaro are designed for long-term use. How long a patient stays on either medication depends on individual health goals, progress, and tolerability. Some people may stay on these medications for months or years — and sometimes indefinitely — to maintain weight loss results or blood sugar control.

Wegovy weight loss results

In a 68-week study with 1,961 participants, those who took Wegovy (semaglutide) at a dose of 2.4 mg per week lost an average of 14.9% of their body weight, compared with 2.4% in the placebo group. Participants also saw improvements in waist circumference, blood pressure, and overall physical fitness.

In the 72-week STEP UP trial, participants who completed the full trial on Wegovy HD (7.2 mg) lost an average of 20.7% of their body weight; about a third lost 25% or more.

Mounjaro weight loss resultsMounjaro contains tirzepatide, the same active ingredient as Zepbound. While Mounjaro was studied primarily in people with type 2 diabetes, some of the strongest evidence for tirzepatide's weight-loss effects comes from dedicated obesity trials.

In a 2022 study of tirzepatide participants who took a weekly 15 mg dose lost an average of 20.9% of their body weight over 72 weeks, compared with 3.1% in the placebo group.

In a head-to-head trial in adults with obesity or overweight but without diabetes, tirzepatide led to greater average weight loss than semaglutide over 72 weeks. Participants received the highest tolerated dose of tirzepatide, 10 mg or 15 mg, or semaglutide, 1.7 mg or 2.4 mg. At 72 weeks, people taking tirzepatide lost an average of 20.2% of their body weight, compared with 13.7% for those taking semaglutide. 

Both medications may cause similar side effects. The most common side effects include gastrointestinal issues such as nausea, diarrhea, and vomiting.

“The frequency and intensity of the side effects vary from patient to patient,” says Marlena Klein, DO, a board-certified physician in internal medicine. “I do tell patients to expect a mild level of nausea the day after they inject the medication.”

Some common side effects of Wegovy include:

• Nausea

• Diarrhea

• Vomiting

• Constipation

• Dizziness

• Heartburn

• Headache

• Gas

• Bloating

• Stomach pain

• Upset stomach

Mounjaro side effects include: 

• Nausea

• Diarrhea

• Vomiting

• Indigestion

• Constipation

• Stomach pain

• Decreased appetite

These side effects tend to be mild and manageable and may improve as the body adjusts, but they can be severe or persistent for some people, especially when starting treatment or increasing the dose.

Dr. Klein says patients should talk to their healthcare provider if symptoms become severe or affect their quality of life. A healthcare provider can help identify ways to manage common side effects or may recommend a different medication.

“Providers can help with patients’ side effects by encouraging stool softeners if constipated, antacid medications if reflux occurs, or fiber tablets if diarrhea occurs,” Dr. Klein says.

Warnings and precautions for Wegovy and Mounjaro

Both Wegovy and Mounjaro may be associated with rare but serious side effects, including:

• Pancreatitis (inflammation of the pancreas)

• Allergic reactions, including anaphylaxis

• Acute kidney injury

• Acute gallbladder disease (gallstones or gallbladder inflammation)

• Vision changes

• Hypoglycemia (low blood sugar)

Both Wegovy and Mounjaro carry a black box warning about thyroid C-cell tumors based on animal studies. It is not known whether these medications cause medullary thyroid carcinoma in humans. As a result, people with a family or personal history of thyroid cancer or tumors may not be good candidates for GLP-1 treatment.

It is important to monitor any symptoms or side effects when taking Wegovy or Mounjaro. Anyone who experiences severe symptoms should stop taking the medication,contact their healthcare provider right away or seek urgent care

Get started

The cost of GLP-1 medications may vary depending on location, insurance coverage, and eligibility for assistance programs.

Getting insurance coverage for weight loss medications such as Wegovy can be challenging. Coverage for Mounjaro is generally tied to its FDA-approved use for type 2 diabetes. Some plans may not cover weight loss medications, or coverage may require prior authorization from the insurance carrier first.

More insurance plans cover Mounjaro when prescribed for type 2 diabetes, but may not cover it or other off-label diabetes medications for weight loss.

You can check with your insurance carrier or use Ro's GLP-1 Insurance Coverage Checker to see what your plan covers. Depending on eligibility, savings cards or patient assistance programs may help reduce costs.

Wegovy cost

The current list price for Wegovy is $1,349.02 per month before insurance or other discounts. Those with a commercial insurance plan that covers Wegovy and who meet certain eligibility requirements may pay as little as $25 per month through the Wegovy Savings Offer (also called the NovoCare Savings Card).

Novo Nordisk also offers a multi-month savings program through telehealth partners such as Ro that may bring the monthly cost of the injection or pill down to $249 per month for 12 months.

Both the Wegovy injection and the Wegovy pill are available on Ro. The Wegovy pill costs $149–$299 per month and the Wegovy injection costs $199–$349 per month, with the exact cost depending on the dose.

Mounjaro cost

The list price for Mounjaro is $1,112.16 per month before insurance, savings programs, or discounts. Those eligible for a Mounjaro Savings Card may pay as little as $25 for a one- or three-month supply.

Eligibility requirements for the Mounjaro Savings Card include:

• Prescribed Mounjaro for an FDA-approved use (type 2 diabetes)

• Enrolled in a commercial insurance plan (state, federal, and government-funded programs — including Medicare and Medicaid — do not qualify)

• A resident of the US or Puerto Rico

• 18 or older

Other ways to save on Wegovy and Mounjaro

Consumer drug sites such as GoodRx and SingleCare may offer pharmacy-specific coupons for Wegovy or other Mounjaro discounts that may help reduce costs.

Ro Body offers access to a licensed healthcare provider for personalized support, coaching, and, where appropriate, medication to support health and weight loss goals. Those interested can get started with a brief questionnaire and a free insurance check.

Both Wegovy and Mounjaro can help with weight management. Wegovy is approved for weight management, and Mounjaro may lead to weight loss even though it is approved for type 2 diabetes.

In a head-to-head trial in adults with obesity or overweight without diabetes, tirzepatide, the active ingredient in Mounjaro and Zepbound led to greater average weight loss than semaglutide over 72 weeks.However, there are various factors to consider when determining which medication is the best fit for an individual's unique needs — including cost and insurance coverage, overall health, side effects, and how well the medication aligns with one's lifestyle and goals.

"The weight loss [these medications] produce can make it easier for a person to be more physically active," says Ted Kyle, RPh, MBA, a registered pharmacist. "These health habits are very personal, which is why personalized plans are essential."

Lifestyle tips to optimize treatment with Wegovy and Mounjaro

For optimal results with either medication, experts recommend following a balanced eating plan, getting regular exercise, and prioritizing healthy habits such as adequate sleep, hydration, and stress management.

“Just because we have more effective options now to aid with weight loss does not mean we should discredit the lifestyle changes that are necessary,” Dr. Klein says. “I typically recommend that patients work with their providers and health coaches to make sustainable changes before turning to medication.” 

Simple adjustments can help you build habits supporting weight management and overall wellbeing while taking a GLP-1. 

• Eat balanced meals. A balanced eating plan includes nutrient-rich foods while minimizing processed items and added sugars.

• Move your body. Aiming for about 150 minutes of exercise each week is a good starting point. Daily walks are an accessible way to stay active, while cardio and strength training may help build muscle and boost metabolism.

• Stay hydrated. Drinking water or other unsweetened beverages throughout the day may help reduce dehydration from potential GI side effects and support feelings of satiety between meals.

• Prioritize sleep. Aiming for 7–9 hours of sleep each night may support the body's ability to repair and recover. Research suggests that regularly getting quality sleep may also help regulate hunger and fullness hormones.

Dr. Klein notes that these tips may also help mitigate weight regain after stopping GLP-1 treatment.

“Inevitably, [patients] may have a minor weight regain because we are removing an appetite suppressant,” she says. “The goal is that it does not return to the original set [weight] point.”

Finding habits that align with one's lifestyle and can be maintained long-term is the most important factor.

A good first step toward finding the right weight loss injection or diabetes treatment is speaking with a healthcare provider, who can help evaluate the potential benefits and drawbacks of each medication.

The following questions may be helpful to discuss with a healthcare provider:

• Am I eligible for weight loss medication?

• Will my insurance cover the medication?

• What types of side effects might I experience?

• How do the risks compare to the benefits I can expect?

• What happens if I stop taking the medication?

• How long will I have to take the medication to see or maintain results?

• Could this medication affect any of my other prescriptions or health conditions?

A healthcare provider plays a crucial role in a weight loss journey. They can offer support, adjust treatment as needed, and monitor progress toward goals.

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Wegovy and Mounjaro share some similarities, but they are two distinct medications with important differences. 

• Wegovy and Mounjaro have different FDA-approved indications. Both medications can be effective for weight loss, but only Wegovy is approved for that purpose. Mounjaro is approved for type 2 diabetes. Tirzepatide, the active ingredient in Mounjaro, is approved for weight management under the brand name Zepbound.

• They work in slightly different ways. Wegovy acts on GLP-1 receptors, while Mounjaro targets both GLP-1 and GIP receptors. This dual-action mechanism may make Mounjaro more effective for weight loss and blood sugar control.

• Research suggests tirzepatide may be more effective than semaglutide for weight loss. In a clinical trial using the maximum dose of Wegovy (2.4 mg weekly), participants lost over 14% of their body weight at 68 weeks. In another trial using 15 mg of tirzepatide (the maximum dose of Mounjaro and Zepbound), patients lost just over 20% of their body weight after 72 weeks.

• Both medications can cause similar side effects, such as nausea, indigestion, and constipation.

• Wegovy and Mounjaro can be expensive. The monthly list price for both medications ranges from approximately $1,100 to $1,350, though insurance, savings programs, and other discounts may significantly lower costs. Weight loss medications and off-label prescriptions may not be covered by insurance.

Consulting a knowledgeable healthcare provider before starting a new medication is strongly recommended. A healthcare provider can evaluate health goals, medical history, and other individual factors to help determine the best treatment approach.