Semaglutide vs Tirzepatide
A factual comparison based on published clinical research
Semaglutide and tirzepatide are the two most widely prescribed GLP-1 medications today. This page compares them using data from published clinical trials so you can have an informed conversation with your healthcare provider.
Two Medications, Different Approaches
While both medications belong to the incretin therapy class, they work through different mechanisms.
GLP-1 Receptor Agonist
- Single-hormone mechanism (GLP-1)
- Brands: Ozempic, Wegovy, Rybelsus
- Manufacturer: Novo Nordisk
- Available as injection or oral tablet
Dual GLP-1/GIP Receptor Agonist
- Dual-hormone mechanism (GLP-1 + GIP)
- Brands: Mounjaro, Zepbound
- Manufacturer: Eli Lilly
- Available as weekly injection
Side-by-Side Comparison
Data sourced from published clinical trials and FDA-approved labeling.
What the Clinical Trials Actually Show
Both medications have been studied in large, multi-center, randomized controlled trials. Here is a summary of published findings.
STEP Trial Program
- STEP 1: 1,961 participants over 68 weeks. Average weight loss of approximately 14.9% of body weight versus 2.4% with placebo.
- Primary endpoint: Percent change in body weight from baseline to week 68.
- Published: New England Journal of Medicine, 2021.
- Population: Adults with BMI of 30 or greater, or 27 or greater with at least one weight-related comorbidity.
SURMOUNT Trial Program
- SURMOUNT-1: 2,539 participants over 72 weeks. Average weight loss of approximately 20.9% of body weight at the highest dose versus 3.1% with placebo.
- Primary endpoint: Percent change in body weight from baseline to week 72.
- Published: New England Journal of Medicine, 2022.
- Population: Adults with BMI of 30 or greater, or 27 or greater with at least one weight-related comorbidity.
Important: These trials enrolled different populations and used different protocols. Direct comparison between separate trials has inherent limitations. No head-to-head trial of semaglutide vs tirzepatide for weight loss has been published as of this writing.
Key Differences
Three fundamental ways these medications differ.
Mechanism of Action
Semaglutide activates GLP-1 receptors, which help regulate appetite and blood sugar. Tirzepatide activates both GLP-1 and GIP receptors, targeting two incretin pathways simultaneously. This dual mechanism is what distinguishes tirzepatide as a first-in-class medication.
Published Efficacy
In their respective pivotal trials, semaglutide produced an average of approximately 15% body weight loss (STEP 1), while tirzepatide produced approximately 21% at the highest studied dose (SURMOUNT-1). Individual results vary significantly from these averages.
Available Formulations
Semaglutide is available as both a weekly injection (Ozempic, Wegovy) and a daily oral tablet (Rybelsus). Tirzepatide is currently available only as a weekly injection (Mounjaro, Zepbound), though oral formulations are being studied.
Which Is Right for You?
Only your healthcare provider can determine which medication is appropriate for your individual health needs. This comparison presents published clinical data to help inform your conversation with your doctor.
Factors your doctor may consider include your medical history, existing conditions, insurance coverage, and treatment goals. The "best" medication is the one that is most appropriate for your specific situation.
Medical Disclaimer: This content is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult your healthcare provider before making any decisions about your health or medications.
Frequently Asked Questions
Common questions about semaglutide and tirzepatide.
Is tirzepatide better than semaglutide?
Clinical trials show higher average weight loss with tirzepatide, but individual responses vary significantly. These trials were conducted separately with different study populations, so direct comparison has limitations. Your doctor can help determine the best option based on your individual health profile.
Are semaglutide and tirzepatide the same thing?
No. They are different medications with different mechanisms of action. Semaglutide targets GLP-1 receptors only, while tirzepatide targets both GLP-1 and GIP receptors. They are made by different manufacturers and sold under different brand names.
Can you switch from semaglutide to tirzepatide?
Medication changes should always be discussed with your prescribing healthcare provider. They can evaluate whether a switch is appropriate for your situation and manage the transition safely.
Do semaglutide and tirzepatide have the same side effects?
They share common gastrointestinal side effects such as nausea, vomiting, and diarrhea, but differ in specifics and frequency. Review the complete published safety data for each medication and discuss any concerns with your doctor.
Which is cheaper, semaglutide or tirzepatide?
Costs vary significantly by brand name, insurance coverage, pharmacy, and available manufacturer savings programs. The list price is not what most patients pay. Check with your insurance provider and pharmacy for the most accurate pricing for your situation.
Does Dose AI track both semaglutide and tirzepatide?
Yes. Dose AI works with any GLP-1 medication, including both semaglutide (Ozempic, Wegovy, Rybelsus) and tirzepatide (Mounjaro, Zepbound). The app tracks injections, symptoms, weight, nutrition, and more regardless of which medication you take.
Track Any GLP-1 Medication
Whether you're on semaglutide or tirzepatide, Dose AI tracks your injections, symptoms, weight, and nutrition in one place.
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