Semaglutide vs tirzepatide: how they compare.
Last updated May 22, 2026
Semaglutide and tirzepatide are both once-weekly injectable medications used for blood sugar and weight management. Semaglutide activates the GLP-1 receptor. Tirzepatide activates two receptors, GIP and GLP-1. PepScribe offers both as compounded formulations prepared by licensed 503A pharmacies in the USA, prescribed by a licensed clinician. Which one fits depends on your medical history and goals, which is what the clinician assessment is for.
At a glance
| Semaglutide | Tirzepatide | |
|---|---|---|
| Drug class | GLP-1 receptor agonist | Dual GIP and GLP-1 receptor agonist |
| How it is taken | Once-weekly subcutaneous injection | Once-weekly subcutaneous injection |
| Primary use | Blood sugar and weight management | Blood sugar and weight management |
| Dosing approach | Gradual titration over several weeks | Gradual titration over several weeks |
| Common side effects | Nausea, reduced appetite, and other GI effects, usually as the dose increases | Similar GI effects; some people report them at higher relative doses |
| Brand-name versions | Ozempic, Wegovy (FDA-approved) | Mounjaro, Zepbound (FDA-approved) |
| At PepScribe | Compounded by a licensed 503A pharmacy, prescribed by a clinician | Compounded by a licensed 503A pharmacy, prescribed by a clinician |
How each one works
Semaglutide is a GLP-1 receptor agonist. It mimics a hormone your gut releases after eating, which helps regulate appetite and blood sugar. Tirzepatide is a dual agonist: it acts on both the GIP and the GLP-1 receptors. The second pathway is the main mechanistic difference between the two, and it is an active area of clinical research rather than a settled claim of superiority for any one person.
Both are taken as a once-weekly subcutaneous injection and are started at a low dose that a clinician increases over several weeks. That titration is what keeps side effects manageable, and it is one reason the medication is prescribed and monitored rather than sold over the counter.
Safety and what to know
The compounded semaglutide and tirzepatide PepScribe offers are not FDA-approved. They are prepared by licensed 503A pharmacies in the USA under a separate regulatory pathway. No hidden overseas supply chain.
Both medications carry the same class of warnings as their brand-name counterparts. Your clinician reviews your personal and family medical history for contraindications before prescribing either one. Results vary from person to person, and neither medication is a guarantee of any specific outcome. This page is educational information, not medical advice.
How PepScribe handles both
You do not have to decide between them on your own. The free assessment routes your answers to a licensed clinician, who recommends the option that fits your history and goals, or neither, if that is the right call. You are not charged for medication unless it is prescribed.
Common questions
Is tirzepatide stronger than semaglutide?
They work differently. Tirzepatide acts on two receptor pathways (GIP and GLP-1), while semaglutide acts on one (GLP-1). Whether that difference matters for you is a clinical judgment your clinician makes against your history and goals. Stronger is not automatically better or safer.
Are compounded semaglutide and tirzepatide FDA-approved?
No. Brand-name semaglutide (Ozempic, Wegovy) and brand-name tirzepatide (Mounjaro, Zepbound) are FDA-approved. The compounded versions PepScribe offers are not FDA-approved. They are prepared by licensed 503A pharmacies in the USA under a separate regulatory pathway, when a clinician determines it is appropriate.
Can I switch between them?
Only under clinician guidance. Switching changes the receptor activity and the titration schedule, so it is a clinical decision rather than a self-serve swap.
How do I know which one is right for me?
Start with the free assessment. A licensed clinician reviews your goals, medical history, and eligibility, then recommends the option that fits. You are not charged for medication unless it is prescribed.
Not sure which fits?
Three-minute assessment. A licensed clinician reviews your goals and recommends the right option, or neither. You are not charged unless medication is prescribed.