Mounjaro vs. Ozempic: What’s a Better Weight Loss Drug?
This blog will explore the key differences, benefits, and side effects between Mounjaro and Ozempic and help you determine which medication is right for you.
What are Mounjaro and Ozempic, and How Do They Work?
Mounjaro and Ozempic were originally developed to help adults with type 2 diabetes control their blood sugar. They do this by mimicking a peptide hormone called GLP-1 (Glucagon-Like-Peptide-1), which boosts insulin production, lowers blood sugar, tells your brain that you are full, and reduces food cravings. While they share these similarities, Mounjaro and Ozempic have some nuanced differences.
Mounjaro
With the generic name tirzepatide, this drug has now been approved as both a weight-loss drug (Zepbound®) and a diabetes medication (Mournjaro®). Tirzepatide is a GLP-1 agonist and a GIP agonist, meaning it mimics these two peptide hormones. These peptides are naturally occurring hormones produced by the gut that affect messaging associated with sugar, glycogen, and lipid metabolism. The dual-action peptides send signals to the brain, affecting appetite and metabolism, making it easier for patients who have historically struggled with weight loss.
Mounjaro differs from Ozempic with the addition of the extra GIP peptide. GIP plus GLP together act synergistically, and studies suggested that Mounjaro leads to some additional weight loss beyond what Ozempic can achieve. (Read below for more information.)
Terzepatide can reduce leptin levels. Leptin mainly acts on your brain stem and hypothalamus, inhibiting or preventing hunger and regulating energy expenditure. When you are well-fed, leptin levels should be high, signaling your body to suppress appetite and burn off fat cell energy as fuel. Overweight or obese people can become leptin-resistant, meaning the brain does not respond as sensitively to leptin. Leptin resistance can lead to feelings of excessive hunger and sluggish use of stored energy (i.e., fat). Tirzepatide may improve leptin sensitivity by regulating leptin and preventing resistance to this powerful satiety hormone.
Ozempic
Prescribed under the brand names Ozempic® and Wegovy®, semaglutide (the generic name) is a glucagon-like peptide-1 (GLP-1) agonist medication. As mentioned above, the GLP-1 agonists keep blood sugar low by stimulating the secretion of insulin and slowing the release of glucagon. This effect on blood sugar facilitates lipolysis or fat-burning. GLP-1 agonists also work on leptin and ghrelin, impacting satiety signaling and hunger.
This drug and delivery has been FDA-approved for Type 2 diabetes. In Ozempic drug trials, significant weight loss was noted amongst participants, and this drug was later developed and approved as a weight loss medication (named Wegovy).
Unlike Mounjaro, Ozempic is FDA-approved to reduce the risk of major cardiovascular events in patients with Type 2 Diabetes and established heart disease.
Do Mounjaro and Ozempic Have Different Dosing Instructions?
Both Mounjaro and Ozempic are taken weekly as an under-the-skin injection in the belly, thigh, or upper arm. Mounjaro and Ozempic are available commercially as a pen-injector. The starting dose for Ozempic is .25mg and the maximum dose is 2mg. For Mounjaro, the starting dose is 2.5mg and the maximum dose is 15mg. Kass Precision Medicine often prescribes a compounded version for more tailored dosing or “micro-dosing,” making it easier for more sensitive patients to dose low and slow. Compounded versions of these medications are delivered with an insulin syringe.
What is the Cost Difference Between Mounjaro and Ozempic?
The average monthly cost of Ozempic (commercial pen-injector version) is between $900 and $1,300 and Mounjaro’s average monthly cost for the commercial pen-injector version ranges between $1,000 to $1,200. For compounded prescriptions, the average monthly cost for Ozempic is $250 - $500 depending on your dose, and Mounjaro costs between $250-$550.
For most patients, insurance does not cover Ozempic or Mounjaro for weight loss.
Mounjaro Vs. Ozempic: How Do Their Results Compare?
On average, Novo Nordisk (the manufacturer of Ozempic) found that people taking Ozempic experienced about a 15% drop in body weight after 68 weeks. Eli Lilly (the manufacturer of Mounjaro) conducted clinical trials showing that patients taking Mounjaro appreciated an average weight reduction of 21.1% after 12 weeks. Over 84 weeks, the total average loss was 26.6%.
For patients who only have a modest amount of weight to lose, Ozempic is often a perfectly effective option that usually has lower side effects. Additionally, many patients start on Ozempic and escalate to Mounjaro if weight loss plateaus.
Ozempic vs Mounjaro: Side Effects
Common Side Effects: Both Mounjaro and Ozempic can cause side effects, including nausea and vomiting, constipation, diarrhea, stomach pain, fatigue, and dyspepsia (acid reflux). Please review the table to learn more about the differences between Ozempic and Mounjaro as well as strategies to mitigate side effects.
Serious Side Effects: Both Ozempic and Mounjaro come with a "boxed warning" about the risk of thyroid cancer. Patients should not use any of these medications if they or anyone in their family has had medullary thyroid carcinoma (MTC) or an endocrine system condition called Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). Other serious side effects include pancreatitis, problems with the gall bladder, and gastroparesis.
*All side effects can be significantly mitigated low and slow. This means using the lowest dose and increasing slowly.
Ozempic vs Mounjaro: Which Medication Is Best?
When determining whether Mounjaro or Ozempic is the best fit, it is vital to consult your physician to determine the safest, most effective choice based on a patient’s unique health needs and medical history. Please visit our medical weight loss page to learn more about our approach.
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