Semaglutide acts on one appetite hormone receptor (GLP-1). Tirzepatide acts on two (GIP and GLP-1). In a head-to-head trial, tirzepatide led to more weight loss on average, and side effects were similar. At CMWL, semaglutide starts at a flat $74/mo and tirzepatide at $119/mo, at any dose.
- Both are once-weekly injections that start low and step up over time.
- Tirzepatide averaged about 20% weight loss vs. about 14% for semaglutide over 72 weeks in the SURMOUNT-5 trial.
- Nausea, diarrhea and constipation are the most common side effects of both, mostly during dose increases.
- Your clinician recommends one based on your health history, goals and budget.
How does each medication work?
Semaglutide mimics GLP-1, a hormone your gut releases after you eat. It slows digestion, helps you feel full sooner and quiets the constant pull toward food.
Tirzepatide mimics GLP-1 and a second hormone, GIP. Acting on both receptors is a key reason many people see a stronger effect on appetite and weight.
What does the research show?
Both medications were studied in large clinical trials of the brand-name versions. Tirzepatide has also been compared with semaglutide directly.
| Topic | Semaglutide | Tirzepatide |
|---|---|---|
| Hormones targeted | GLP-1 | GIP + GLP-1 |
| How often | Once weekly | Once weekly |
| Average weight loss in its main trial* | About 15% (STEP 1, 68 weeks) | About 21% (SURMOUNT-1, 72 weeks) |
| Head to head (SURMOUNT-5)* | 13.7% | 20.2% |
| Most common side effects | Nausea, diarrhea, constipation | Nausea, diarrhea, constipation |
| CMWL starting price | $74/mo flat | $119/mo flat |
*Results from clinical trials of brand-name medications at the highest studied doses. Compounded medications were not studied in these trials and are not FDA-approved. Individual results vary.
Are the side effects different?
Not much. Both cause similar stomach-related effects, mostly in the first weeks and right after a dose increase. Starting low, eating smaller meals and staying hydrated helps. Your care team can slow the pace if you need it.
Watch next: What side effects to expect →How much does each cost at CMWL?
One flat price at every dose, so your cost does not climb as your dose does. On the annual plan, semaglutide starts at $74/mo and tirzepatide at $119/mo. Monthly plans are $149 and $239.
Which one is right for you?
There is no universal winner. Your clinician weighs your health history, current medications, goals, how you have responded to GLP-1s before and your budget. Some people start on semaglutide and move to tirzepatide later if they need more support.
Frequently asked questions
Is tirzepatide stronger than semaglutide?
On average, yes. In the SURMOUNT-5 head-to-head trial, people on tirzepatide lost more weight than people on semaglutide over 72 weeks. Stronger is not right for everyone, so your clinician matches the medication to you.
Can I switch from semaglutide to tirzepatide?
Yes, with your clinician’s guidance. Switching usually means starting tirzepatide at an appropriate dose rather than picking up where you left off.
Are compounded versions the same as Wegovy or Zepbound?
No. Compounded medications are prepared by a licensed pharmacy for an individual patient and are not FDA-approved. They were not studied in the brand-name trials cited above. Your clinician explains the differences before you start.
Does my price change if my dose goes up?
No. CMWL charges the same price at every dose.
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Sources
- Wilding JPH, et al. Once-weekly semaglutide in adults with overweight or obesity (STEP 1). N Engl J Med. 2021;384:989-1002.
- Jastreboff AM, et al. Tirzepatide once weekly for the treatment of obesity (SURMOUNT-1). N Engl J Med. 2022;387:205-216.
- Aronne LJ, et al. Tirzepatide as compared with semaglutide for the treatment of obesity (SURMOUNT-5). N Engl J Med. 2025.
- U.S. Food and Drug Administration. Compounding and the FDA: questions and answers.
CMWL Chief Medical Officer and Yale-trained physician. Last reviewed October 14, 2026.
Read full bio →This article is for education only and does not replace personalized medical advice. Compounded medications are not FDA-approved. Talk to a licensed clinician about the risks and benefits of any treatment.
