What is the difference between Wegovy (semaglutide) and tirzepatide?
Wegovy is a brand name for semaglutide, a GLP-1 (glucagon-like peptide-1) receptor agonist made by Novo Nordisk. The same active ingredient appears in Ozempic at a lower weekly dose, primarily marketed for type 2 diabetes management. Semaglutide binds to and activates the GLP-1 receptor, which slows gastric emptying, reduces appetite signaling, and supports insulin secretion in a glucose-dependent way.
Tirzepatide is a dual GIP/GLP-1 receptor agonist developed by Eli Lilly. It activates both the GIP (glucose-dependent insulinotropic polypeptide) receptor and the GLP-1 receptor simultaneously. GIP signaling plays a complementary role to GLP-1 in post-meal insulin response, fat metabolism, and appetite regulation. Tirzepatide is sold as Mounjaro for type 2 diabetes and as Zepbound for chronic weight management. It is not the same molecule as semaglutide.
How do Ozempic, Wegovy, Mounjaro, and Zepbound map to their active ingredients?
The brand-name landscape has contributed to widespread confusion. Here is how each brand maps to its active ingredient and FDA indication:
| Brand | Active ingredient | Receptor target | FDA approval |
|---|---|---|---|
| Ozempic | Semaglutide | GLP-1 | Type 2 diabetes |
| Wegovy | Semaglutide (2.4 mg) | GLP-1 | Chronic weight management |
| Mounjaro | Tirzepatide | GIP + GLP-1 | Type 2 diabetes |
| Zepbound | Tirzepatide | GIP + GLP-1 | Chronic weight management |
The core takeaway: Ozempic and Wegovy are the same active ingredient (semaglutide). Mounjaro and Zepbound are the same active ingredient (tirzepatide). Semaglutide and tirzepatide are different molecules.
Which is more effective, semaglutide or tirzepatide? What the trial data shows
Both drugs have substantial clinical trial data supporting their use in weight management. The STEP 1 trial of semaglutide showed participants losing an average of approximately 15% of body weight over 68 weeks. The SURMOUNT-1 trial of tirzepatide showed average weight loss of up to approximately 21% at the highest dose over 72 weeks.
A direct head-to-head comparison in the SURMOUNT-5 trial found that tirzepatide produced statistically greater average weight loss than semaglutide in adults with obesity who did not have type 2 diabetes. That said, individual response varies considerably based on metabolic factors, adherence, diet, activity, and other medications. A higher average in a population trial does not mean tirzepatide will produce better results for every individual.
Side effect profiles are broadly similar between the two: nausea, vomiting, diarrhea, and constipation are the most commonly reported adverse effects for both, particularly during dose titration. Both carry boxed warnings related to thyroid C-cell tumor risk observed in rodent studies. Neither is appropriate for everyone, and medical supervision is essential.
What does compounded semaglutide or tirzepatide actually mean?
During periods when FDA-approved branded versions have been on shortage lists, licensed 503A compounding pharmacies in the United States have been permitted to prepare compounded versions of semaglutide and tirzepatide for individual patients under a clinician prescription. Compounded medications are not FDA-approved drugs — they are prepared individually for a specific patient by a licensed pharmacy, not manufactured at scale.
The 503A designation refers to a specific compounding framework under federal law. PepScribe works exclusively with licensed 503A pharmacies that compound in the USA. There is no hidden overseas supply chain. Compounding is performed by licensed US pharmacies following USP standards, not by overseas or unverified manufacturers.
The compounding landscape for these agents is subject to ongoing FDA oversight and can change as shortage status evolves. A clinician consultation is the appropriate path to determine which agent and which route — branded or compounded — is applicable for your situation.
Which should you consider?
This is not a question a comparison article can answer for you. Semaglutide and tirzepatide are both prescription medications that require a clinician evaluation before prescribing. Factors a clinician will consider include your medical history, current medications, contraindications (such as personal or family history of certain thyroid conditions or pancreatitis), your degree of obesity, metabolic comorbidities, and your goals.
The right clinician-supervised weight management approach looks at the full picture — not just which drug has the higher average weight loss in a trial. Starting with an honest assessment is the first step.
Frequently asked questions
Is Wegovy the same as tirzepatide?
No. Wegovy contains semaglutide, a GLP-1 receptor agonist. Tirzepatide (sold as Zepbound for weight management) is a dual GIP/GLP-1 receptor agonist — a different molecule with a different mechanism.
What is Wegovy made of?
Wegovy is a brand name for semaglutide, a GLP-1 receptor agonist originally developed by Novo Nordisk. The same active ingredient appears in Ozempic at a lower dose for type 2 diabetes management.
What is tirzepatide used for?
Tirzepatide is FDA-approved under the brand Zepbound for chronic weight management and under the brand Mounjaro for type 2 diabetes. As a dual GIP/GLP-1 agonist it activates two incretin pathways simultaneously.
Which is more effective, semaglutide or tirzepatide?
Head-to-head trials (SURMOUNT-5) showed tirzepatide produced greater average weight loss than semaglutide in adults with obesity. Individual response varies; a clinician review considers your history before recommending either.
Can I get compounded semaglutide or tirzepatide without a brand-name prescription?
Licensed 503A compounding pharmacies in the US may compound these active ingredients for eligible patients under a clinician prescription. A clinician evaluation is required first to determine suitability.
Are compounded GLP-1 medications FDA-approved?
No. Compounded medications are not FDA-approved drugs. They are prepared by licensed 503A pharmacies under a clinician prescription for individual patients and are not interchangeable with branded FDA-approved products.