Semaglutide vs Tirzepatide: Comparing GLP-1 Medications for Weight Loss

Semaglutide is a GLP-1 receptor agonist, per FDA prescribing information. On the GLP-1 Near site, that usually means patients are hearing about Wegovy for chronic weight management and Ozempic for type 2 diabetes. Wegovy received FDA approval for chronic weight management in June 2021, while Ozempic was approved in 2017 for type 2 diabetes. That difference matters because the approved indication on the label is not the same thing as how a drug may be discussed online or prescribed in practice.

For weight management, the most cited semaglutide result is the STEP 1 trial published in NEJM in 2021. In that study, average weight loss with Wegovy was 14.9% over 68 weeks compared with 2.4% with placebo. Other semaglutide trials show different outcomes depending on the population: STEP 2 reported 9.6% average weight loss in adults with type 2 diabetes, and STEP 3 reported 16% with intensive behavioral therapy. Those are average clinical-trial results, not guarantees for any individual patient.

Per FDA prescribing information, Wegovy is started at 0.25 mg weekly and increased monthly until a 2.4 mg maintenance dose. Common side effects listed on the Wegovy label include nausea, diarrhea, vomiting, constipation, and abdominal pain. The label also carries a boxed warning about thyroid C-cell tumors observed in rodents, plus warnings about pancreatitis, gallbladder problems, and kidney injury. Those are exactly the kinds of factors patients should review with a qualified clinician before starting treatment.

Tirzepatide is a dual GIP/GLP-1 receptor agonist, per FDA prescribing information. That is one of the main scientific distinctions between tirzepatide and semaglutide. Eli Lilly markets tirzepatide as Mounjaro for type 2 diabetes and Zepbound for chronic weight management. Just like the semaglutide brands, the approved indication depends on the specific label, so patients and clinics should be careful not to treat those brand names as interchangeable from a regulatory standpoint.

The most widely cited tirzepatide weight-loss result is the SURMOUNT-1 trial, published in NEJM in 2022. At the highest 15 mg dose, average weight loss was 20.9% over 72 weeks compared with 3.1% for placebo. SURMOUNT-2 reported 14.7% average weight loss in adults with type 2 diabetes, and SURMOUNT-3 reported 26.6% when tirzepatide was paired with intensive lifestyle intervention. Again, those are trial averages under specific study conditions, not promises about what any one person will experience.

Per FDA prescribing information, tirzepatide starts at 2.5 mg once weekly and is increased over time. The Zepbound label lists nausea, diarrhea, decreased appetite, vomiting, constipation, and dyspepsia among common side effects. Tirzepatide also has a boxed warning for thyroid C-cell tumors observed in rodents and includes warnings about pancreatitis, gallbladder problems, and hypoglycemia when used with insulin. Patients comparing these medications should discuss those risks with their healthcare provider.

Wegovy is typically about $1,300-1,400 per month without insurance as of early 2025, while Ozempic is typically about $900-1,000 per month.

Zepbound and Mounjaro are typically about $1,000-1,100 per month without insurance as of early 2025.

Prices vary by pharmacy and location, and manufacturer savings programs may change actual out-of-pocket costs.

Insurance coverage often matters more than list price, so this is an important factor to discuss with your doctor and pharmacy.

Pricing is approximate and based on the reference file as of early 2025. Prices vary by pharmacy and location. Consult your healthcare provider and pharmacy for current pricing.