Over the past several years, two new medications have emerged as significant players in the realm of diabetes management and weight loss: Mounjaro (tirzepatide) and Wegovy (semaglutide). While both brands belong to the same class of drugs, known as GLP-1 receptor agonists, they have distinct characteristics, mechanisms of action and suitability for different patients.

This post aims to unravel these differences, providing clarity on how Mounjaro and Wegovy work, their specific Food and Drug Administration (FDA) approvals and their individual side effects and prices. Whether you're a patient considering these options or simply curious about the latest advancements in medical treatments, this post will provide you with a comprehensive understanding of these two medications.

What is Mounjaro?

Mounjaro is the brand name for the medication tirzepatide, which was approved by the FDA in May of 2022 for the treatment of type 2 diabetes. Mounjaro, which is manufactured by the pharmaceutical company Eli Lilly, belongs to a class of drugs called glucagon-like peptide-1 (GLP-1) receptor agonists, which help in regulating blood sugar levels.

Mounjaro, which is administered as a weekly injection, works by simultaneously activating two different types of receptors in the body: the glucagon-like peptide-1 (GLP-1) receptor and the glucose-dependent insulinotropic polypeptide (GIP) receptor. In simpler terms, the medication helps with several important functions:

• Helping your pancreas: Your pancreas controls how much sugar is in your blood via a hormone called insulin, but if you have type 2 diabetes, your pancreas struggles to control how much insulin to release. Mounjaro helps your pancreas release insulin when your blood sugar is high, which lowers your blood sugar levels.
  
• Slowing down food absorption: When you eat, food breaks down into sugar, which goes into your blood. Mounjaro slows this process down, so sugar enters your bloodstream more slowly. It's like telling a crowd of people to enter a concert venue in an orderly line instead of all rushing in at once.
  
  

In general, higher doses of tirzepatide — the active ingredient in Mounjaro — are also shown to produce significant effects on body weight, but it isn’t indicated for weight loss; in other words, while weight loss is a side effect of Mounjaro, prescribing it for weight loss is an off-label use of the medication.

What is Wegovy?

Wegovy, another GLP-1 receptor agonist, contains the active ingredient semaglutide (which is also found in Ozempic, a similar medication). Unlike Mounjaro, Wegovy was FDA-approved in June of 2021 specifically for adults with obesity, or those who are overweight with weight-related health conditions like high blood pressure, high cholesterol, or type 2 diabetes.

Like Mounjaro, Wegovy is administered via a weekly injection, and its primary action is to mimic the incretin hormones, which increases insulin production and lowers blood sugar levels. It has shown significant effectiveness in weight reduction, especially when combined with lifestyle changes.

What is more effective, Mounjaro or Wegovy?

Since Wegovy is indicated for weight loss and Mounjaro is indicated for type 2 diabetes, comparing the effectiveness of these medications is complex.

For example, during Wegovy clinical trials, a significant number of people who took Wegovy (between 67.4% and 84.8%) lost 5% or more of their body weight over the course of 68 weeks.

In contrast, participants in Mounjaro clinical trials were studied based upon reductions to their A1c levels (a measure of blood sugar that can indicate diabetes). Participants saw A1c reductions from 1.7% to 2.4% for different dosages of Mounjaro - but in addition, those participants also achieved weight loss between 12 lbs. to 25 lbs. on average.

However, recent studies have found that patients on tirzepatide (the active ingredient in Mounjaro) were significantly more likely to achieve 5%, 10% and 15% weight loss and experience larger reductions in weight at 3, 6, and 12 months than those on semaglutide (the active ingredient in Wegovy).

While both drugs can lead to significant weight loss and improved blood sugar levels in people with type 2 diabetes, it’s also important to remember that the extent of effectiveness can vary based on individual factors such as body mass index (BMI), existing health conditions and adherence to the treatment plan.

What are the side effects of Wegovy and Mounjaro?

The most common side effects reported by Wegovy users include:

• Gastrointestinal issues (constipation, diarrhea, gas, bloating, nausea, and/or an upset stomach)
  
• Vomiting
  
• Headache
  
• Tiredness (fatigue)
  
• Dizziness
  
• Belching
  
• Stomach flu
  
• Heartburn
  
• Runny nose
  
• Sore throat
  
  The most common side effects of Mounjaro include gastrointestinal issues (constipation, diarrhea, gas, bloating, nausea, and/or an upset stomach). Some people have also reported injection site reactions, like redness or swelling. While less common, more severe side effects of Mounjaro include allergic reactions, low blood sugar (hypoglycemia), as well as an increased risk of thyroid cancer, gallbladder disease and acute pancreatitis.

If you experience ongoing or severe symptoms while using either of these medications, it’s important to contact your healthcare provider right away.

It’s also important to note that both Mounjaro and Wegovy are contraindicated during pregnancy for weight loss, which means they should be avoided if you are trying to get pregnant. Both medications should also be avoided if you have a personal history of pancreatitis, type 1 diabetes, diabetic retinopathy (a diabetes condition that affects eyesight), or a personal or family history of medullary thyroid cancer or multiple endocrine neoplasia.

Which drug is more expensive, Mounjaro or Wegovy?

The cost of GLP-1 medications is largely dependent on your insurance status. If you’re insured, the price of these medications depends on the rates negotiated by your insurer.

Without insurance, Mounjaro (tirzepatide) usually costs between $1,020 to $1,200 per month, while Wegovy (semaglutide) usually costs between $1,300-$1,600 per month before insurance. Both medications are on the higher end of the price spectrum for weight loss and diabetes medications.

Do Wegovy and Mounjaro have generic versions?

Currently, there are no generic versions of either Mounjaro or Wegovy available. Both medications are relatively new on the market and are still protected by patents. This means that for the time being, only the brand-name versions are available, which contributes to their higher cost.

For those struggling with obesity or type 2 diabetes, Mounjaro and Wegovy represent significant advancements in GLP-1 medication options. If you meet the criteria for these medications, it's essential to have a discussion with your healthcare provider. They can help determine which medication is right for you based on your specific health needs and treatment goals.

How can Sesame help with my weight loss goals?

Sesame offers a comprehensive online weight loss program to help you get started on your weight loss journey. Sesame’s online weight loss program is a subscription which renews every 3 months and includes a video consultation with a weight loss doctor or specialist, a GLP-1 prescription (if appropriate), insurance coordination for medication coverage, and 90 days of unlimited messaging with your provider. Note that all prescriptions are at the discretion of your clinician.

Sources:

• Abbasi J. FDA Green-Lights Tirzepatide, Marketed as Zepbound, for Chronic Weight Management. JAMA.
  
• Chavda, V. P., Ajabiya, J., Teli, D., Bojarska, J., & Apostolopoulos, V. (2022). Tirzepatide, a New Era of Dual-Targeted Treatment for Diabetes and Obesity: A Mini-Review. Molecules.
  
• Vilsbøll T, Christensen M, Junker AE, Knop FK, Gluud LL. Effects of glucagon-like peptide-1 receptor agonists on weight loss: systematic review and meta-analyses of randomised controlled trials. BMJ.