Which Medication is Better for Weightloss? Wegovy or Mounjaro?

Physician-reviewed GLP-1 comparison

Tirzepatide vs. Semaglutide for Weight Loss

Direct comparative evidence shows greater average weight loss with tirzepatide, but the best medication still depends on medical history, indication, tolerability, coverage and goals.

Medically reviewed by Dr. Timothy Mackey
Medical Director · Updated September 2026

Wegovy, Zepbound, Ozempic and Mounjaro: what is the difference?

Semaglutide is the active drug in Wegovy and Ozempic. Wegovy is the weight-management brand; Ozempic is primarily a type 2 diabetes product. Tirzepatide is the active drug in Zepbound and Mounjaro. Zepbound is the weight-management brand; Mounjaro is a type 2 diabetes product.

For obesity, the cleanest brand comparison is therefore Wegovy vs. Zepbound. For treatment details, see the semaglutide and tirzepatide pages.

How do they work?

Semaglutide activates the GLP-1 receptor, affecting appetite, satiety, gastric emptying and glucose-dependent insulin signaling. Tirzepatide activates both GIP and GLP-1 receptors.

What does the head-to-head evidence show?

SURMOUNT-5 used maximum tolerated weekly injections: tirzepatide 10 or 15 mg versus semaglutide 1.7 or 2.4 mg. It did not compare tirzepatide with oral Wegovy or Wegovy HD 7.2 mg. Those current formulations should not be treated as if they were tested in this trial. Check the current Wegovy labeling for formulation-specific instructions.

SURMOUNT-5 directly compared tirzepatide with semaglutide in adults with obesity without diabetes. Mean weight reduction at 72 weeks was about 20.2% versus 13.7%, respectively, with greater average waist reduction for tirzepatide.

Earlier pivotal trials also showed substantial weight loss with both medications, but direct randomized comparison is more useful than comparing separate trials.

Which patients qualify?

For adult chronic weight management, a common eligibility threshold is BMI ≥30 kg/m², or BMI ≥27 kg/m² with at least one weight-related condition, subject to the specific FDA-approved product labeling and individual clinical assessment.

Cardiovascular disease and sleep apnea can affect the choice

Wegovy has an FDA indication to reduce major cardiovascular events in certain adults with established cardiovascular disease and overweight or obesity. Zepbound has an FDA-approved indication for moderate-to-severe obstructive sleep apnea in adults with obesity. These disease-specific indications can matter more than a simple comparison of pounds lost.

Side effects and important warnings

Both commonly cause nausea, diarrhea, vomiting, constipation and abdominal symptoms, especially during dose escalation. Both labels include a boxed warning regarding thyroid C-cell tumors observed in rodents and contraindications involving personal or family history of medullary thyroid carcinoma or MEN2. Other warnings include pancreatitis, gallbladder disease, kidney injury related to volume depletion and severe gastrointestinal reactions.

Pregnancy is not an appropriate setting for intentional pharmacologic weight loss. Tirzepatide also has specific counseling regarding oral hormonal contraceptive effectiveness during initiation and dose escalation.

Are compounded versions the same?

No. Compounded semaglutide and tirzepatide are not FDA-approved generic equivalents of Wegovy or Zepbound and do not undergo the same FDA premarket review. Patients should know what product they are receiving, why it is being compounded and which pharmacy dispenses it.

Which costs less?

Cost depends on insurance, manufacturer programs, pharmacy, dose and whether a clinic bundles medication, visits, labs, supplies or shipping. A low advertised starting price can become much more expensive when doses increase.

Before enrolling, ask whether the price changes with titration and check independent patient reviews for hidden fees, required memberships or bait-and-switch pricing.

Which is better?

Tirzepatide produced greater average weight loss in SURMOUNT-5 at the doses studied; this does not establish superiority over every semaglutide formulation. The best treatment for an individual may still be semaglutide because of cardiovascular indication, tolerability, availability, cost, prior response or another clinical consideration.

Frequently asked questions

Is Zepbound stronger than Wegovy?

Tirzepatide produced greater average weight loss than semaglutide in SURMOUNT-5, but “stronger” does not account for safety, tolerability or individual indication.

Is Mounjaro the same as Zepbound?

They contain tirzepatide but are different branded products with different labeled indications.

Is Ozempic the same as Wegovy?

Both contain semaglutide but have different labeled indications and dosing regimens.

Can patients switch between them?

Sometimes, but there is no universal milligram-for-milligram conversion. A prescriber should plan the transition.

Medical references

• SURMOUNT-5: Tirzepatide as Compared with Semaglutide for Obesity
• STEP 1: Semaglutide in Adults with Overweight or Obesity
• SURMOUNT-1: Tirzepatide Once Weekly for Obesity

This article is educational and does not replace individualized medical advice or current prescribing information.