Weight Loss
21 min read
Written by Douglas Helm
Published: Mar 11, 2024
Medically Reviewed by Goldina Erowele, PharmD, MBA
If you look into weight loss medications, you may come across Wegovy (semaglutide) and Mounjaro (tirzepatide) or Zepbound (tirzepatide) in your search. But what are the differences between Wegovy vs Mounjaro? And what is Zepbound?
In this article, we go over what they’re used for, which is best for losing weight, and more. We review how these medications work and potential side effects. By the end of this article, you’ll have the knowledge and confidence to talk to your healthcare provider about the best prescription weight loss medications and weight loss programs for you. Let’s dive in.
Wegovy and Mounjaro are both injectable prescription drugs.
Wegovy contains the active ingredient semaglutide and is U.S. Food and Drug Administration (FDA)-approved for weight loss in individuals with a body mass index (BMI) at or above 30 or with a BMI at or above 27 who have a weight-related health condition, such as heart disease, type 2 diabetes, or high blood pressure. It’s also approved for children aged 12 and older with obesity and a BMI in the 95th percentile for their sex and age.
Wegovy should be used along with exercise and a reduced-calorie diet.
You may have also heard of Ozempic (semaglutide). Ozempic is an injectable medication that also has semaglutide as the active ingredient. It though is FDA-approved to lower blood sugar levels in adults with type 2 diabetes. Ozempic was FDA-approved before Wegovyand has been used off-label for weight loss. More on that below.
Ozempic and Wegovy are both made by Novo Nordisk.
Mounjaro contains the active ingredient tirzepatide and is FDA-approved to improve blood sugar (glucose) in adults with type 2 diabetes. Like Wegovy, it’s prescribed along with exercise and diet changes. Mounjaro isn’t FDA-approved for weight loss but has been used off-label for this purpose.
Zepbound is a newer weight-loss medication with the same active ingredient and same formulation as Mounjaro. Zepbound and Mounjaro are both made by Eli Lilly. Eli Lilly first made Mounjaro. And in just November 2023, got FDA-approval for a rebranded version, called Zepbound, for weight loss.
Like Wegovy, Zepbound is approved for use in adults with a BMI at or above 30 or at or above 27 who have a weight-related health condition along with diet and exercise. It’s not approved for use in children under 18.
Brand | Wegovy | Zepbound and Mounjaro |
Drug class | GLP-1 agonist | Dual GLP-1 and GIP receptor agonists |
Active ingredient | Semaglutide | Tirzepatide |
Generic | None available | None available |
Form(s) | Liquid administered by injection | Liquid administered by injection |
Dosing | Starting dose: – 0.25 mg injected subcutaneously once a week – After week 4: 0.5 mg once a week – After week 8: 1 mg once a week – After week 12: 1.7 mg once a week – After week 17 for some: 2.4 mg once a week – Maintenance dose is 1.7 mg or 2.4 mg – Maximum dose: 2.4 mg | Starting dose: – 2.5 mg injected subcutaneously once a week – After 4 weeks, 5 mg once a week – Can be increased in 2.5 mg increments every 4 weeks if needed – Recommended maintenance doses are 5 mg, 10 mg, or 15 mg once a week – Maximum dose is 15 mg once a week |
Frequency | Weekly subcutaneous injection | Weekly subcutaneous injection |
Approved for | Weight loss for: Adults with body mass index (BMI) at or above 30Adults with a BMI at or above 27 with a weight-related health condition Children 12 or older with a BMI at or above the 95th percentile for their sex and age Should be used with a reduced-calorie meal plan and increased physical activity | Zepbound Weight loss in: Adults with a BMI at or above 30Adults with a BMI at or above 27 with a weight-related health condition Should be used with a reduced-calorie meal plan and increased physical activity Mounjaro To improve blood sugar (glucose) in: Adults with type 2 diabetes Should be used with diet and exercise |
Retail Cost | $1,430 for a 28-day supply* | Zepbound $1,126 for a 28-day supply* Mounjaro $1,135 for a 28-day supply* |
Common side effects | Nausea Diarrhea Stomach pain Upset stomach Dizziness Bloating Gas Fatigue Headache Vomiting Constipation Heartburn Runny nose Sore throat | Zepbound Nausea Diarrhea Vomiting Constipation Stomach pain Indigestion Injection site reactions Feeling tired Belching Hair loss Heartburn Mounjaro Nausea Diarrhea Decreased appetite Vomiting Constipation Indigestion Stomach pain |
Serious side effects | Allergic reaction Inflammation of the pancreas (pancreatitis) Gallbladder problems Low blood sugar (hypoglycemia) Kidney problems Changes in vision Increased heart rate Suicidal behavior or thoughts | Zepbound Allergic reaction Inflammation of the pancreas (pancreatitis) Gallbladder problems Low blood sugar (hypoglycemia) Kidney problems Changes in vision Severe stomach problems Mounjaro Allergic reaction Inflammation of the pancreas (pancreatitis) Gallbladder problems Low blood sugar (hypoglycemia) Kidney problems Changes in vision Severe stomach problems |
Box warning | Risk of thyroid tumors, including cancer See full prescribing information for complete box warning. | Risk of thyroid tumors, including cancer See full prescribing information for complete box warning. |
Weight loss potential | Average 14.9% reduction in body weight (data) | Zepbound Average 18% reduction in body weight on the highest dose of Zepbound (data) Mounjaro Average of 12–25 lbs of weight loss (data) |
Wegovy is in a drug class known as glucagon-like peptide-1 (GLP-1) agonists. The 2 most commonly approved uses for GLP-1 receptor agonists are type 2 diabetes and chronic weight management. GLP-1 medications work by mimicking hormones called incretin. These hormones increase insulin production, which helps lower blood sugar. GLP-1 agonists also make you feel less hungry, which is why GLP-1 agonists work for weight loss.
Mounjaro and Zepbound are dual agonist medications. They mimic both the GLP-1 hormone and the gastric inhibitory polypeptide (GIP) hormone. Some studies indicate that dual agonists offer better blood sugar level control and weight loss benefits than GLP-1 agonists. This makes these weight loss drugs well-suited for those with type 2 diabetes as well as for chronic weight management.
All 3 medications lead to weight loss.
An ongoing randomized controlled study is comparing the safety and effectiveness of semaglutide, (which is the active ingredient n Wegovy and Ozempic) directly against tirzepatide (which is the active ingredient in Mounjaro and Zepbound). Trial participants are obese or overweight with weight-related health conditions and do not have type 2 diabetes. The trial is set to complete in 2024. It should provide a clear picture of these medications’ comparative weight loss benefits.
Because individual responses to weight loss medications vary, you should discuss whether to use Zepbound vs Mounjaro vs Wegovy with your healthcare provider.
Without insurance, the retail cost of Wegovy is $1,430 for a 28-day supply, Mounjaro $1,135, and Zepbound $1,126 (costs per drugs.com). There are no lower-cost generic versions available.
Your insurance plan may cover Wegovy, Mounjaro, or Zepbound. Your cost will depend on your plan’s coverage, co-pay, deductible, and out-of-pocket costs. And your plan may not cover an off-label use, such as using Mounjaro for weight loss.
These medications may also require prior authorization. This is a process where your healthcare provider must get approval from your health insurance company before it covers the cost.
Refer to your benefits plan documents or check with your insurance provider to understand your coverage. If they don’t cover your medication or deny authorization, you or your healthcare provider can appeal.
If you have commercial insurance with prescription drug coverage and use the Novo Nordisk Wegovy Savings Card, you could pay as little as $0 for a 28-day supply. This card is subject to a maximum savings of $225. If your insurance doesn’t cover Wegovy or if you pay cash, you can save up to $500 for a 28-day supply. See Novo Nordisk’s Wegovy website for details.
If you have commercial insurance with prescription coverage and use the Zepbound Savings Card, you could pay as little as $25 for a 28-day supply of Zepbound. Saving is subject to a maximum of $150 per 28-supply or $1,800 per calendar year. If your insurance doesn’t cover Zepbound, you may pay as little as $550 for a 28-day supply with a maximum savings of $563 per 28-day supply or $7,319 per calendar year. See the Elli Lilly Zepbound website for details.
If you have commercial insurance with prescription coverage, you could pay as little as $25 for a 28-day supply of Mounjaro. This offer is subject to a maximum savings of $150 for a 28-day supply or $1,800 per calendar year. If your insurance doesn’t cover Mounjaro, you can save up to $575 a month or $3,450 each calendar year. See the Elli Lilly Mounjaro website for details.
Be aware of the potential risks and side effects before starting a medication. Make sure to report any side effects to your healthcare provider.
The most common side effects of Wegovy include:
Common side effects of Mounjaro and Zepbound include:
Box warnings are the most serious safety warning issued by the FDA. They warn providers and patients about serious side effects and issues for a medication. The boxed warning for Wegovy, Mounjaro, and Zepbound warns of possible thyroid tumors, including cancer. And none of these medications should be taken if you or a family member have ever had a type of thyroid cancer called medullary thyroid Carcinoma or if you have an endocrine system condition called Multiple Endocrine Neoplasia syndrome type 2.
Wegovy, Mounjaro, and Zepbound also come with risks of serious side effects.
Wegovy includes warnings for:
Mounjaro and Zepbound include warnings for:
Switching from Wegovy to Zepbound or Monjaro to Ozempic, or vice-versa, is possible. if you experience side effects or aren’t seeing results, talk to your healthcare provider about making a switch. They can help you determine if the switch is right for you. They can also guide you through the process of getting off your current medication and starting a new one.
Make sure to closely follow any instructions your healthcare provider gives you when switching. Also, make sure to report any side effects, so your provider can adjust your treatment as necessary.
It’s always helpful to be prepared when you speak to your healthcare provider. This way, you get all of your questions answered. Here’s a quick list of common questions to ask your provider about Wegovy and Zepbound for medical weight loss.
Off-label use is prescribing a drug to treat a condition other than what it is FDA-approved to treat. For example, using Mounjaro for weight loss when it’s approved for improving blood sugar (glucose) in people with type 2 diabetes but not weight loss.
The off-label use of type 2 diabetes medications for weight loss has been high, which has led to shortages, including for Ozempic and Wegovy. These shortages have made it difficult for those with diabetes or trying to lose weight to find the medication they need. And insurance companies have cracked down on the off-label prescribing of Ozempic for weight loss drugs.
Both Wegovy and Zepbound are approved for weight loss, while Mounjaro is approved to improve blood sugar (glucose) for people with type 2 diabetes. Mounjaro could be used off-label for weight loss but doesn’t need to be with the availability of Zepbound.
Talk to your healthcare provider about weight loss medications like Wegovy and Zepbound. You and your provider can discuss if one of these medications is right for you, side effects, and weight loss potential compared to your health history and weight loss needs.
Looking for help with medically supervised weight loss? Find a provider on Klarity and get the expert medical advice and support you need for your weight loss journey. The Klarity platform helps you find a provider and get an appointment within 48 hours. Find a licensed provider now.
The information provided in this article is for educational purposes only and should not be construed as medical advice. Always seek the guidance of a qualified healthcare professional with any questions or concerns you have regarding your health.
How we reviewed this article: This article goes through rigorous fact-checking by a team of medical reviewers. Reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the author.
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