# Semaglutide vs Tirzepatide: How They Differ | PepVault Source: https://pepvault.app/peptides/compare/semaglutide-vs-tirzepatide Last updated: 2026-09-26 [Library](https://pepvault.app/peptides) [Comparisons](https://pepvault.app/peptides/compare) Semaglutide vs Tirzepatide Compared side by side # Semaglutide vs tirzepatide: how they differ Reviewed September 2026 [How we check the library](https://pepvault.app/about#library) ## The short answer Semaglutide is a GLP-1 receptor agonist; tirzepatide activates the GLP-1 receptor and the GIP receptor too. Both are FDA-approved weekly shots: semaglutide as Ozempic and Wegovy, tirzepatide as Mounjaro and Zepbound. In the SURMOUNT-5 head-to-head trial, tirzepatide produced 20.2% weight loss at 72 weeks against 13.7% for semaglutide. ## Side by side | Compared | [Semaglutide](https://pepvault.app/peptides/semaglutide) | [Tirzepatide](https://pepvault.app/peptides/tirzepatide) | | --- | --- | --- | | Category | Metabolic & GLP-1 | Metabolic & GLP-1 | | Also known as | Ozempic, Wegovy | Mounjaro, Zepbound, LY3298176 | | What it is | A GLP-1 receptor agonist that mimics a gut hormone your body releases after eating: it reduces appetite and slows stomach emptying. | The first dual GIP/GLP-1 receptor agonist: it activates two gut-hormone pathways at once, and in a head-to-head trial it produced more weight loss than semaglutide (20.2% vs 13.7% at 72 weeks). | | How it works | GLP-1 receptor agonist that reduces appetite, slows gastric emptying, and improves glucose metabolism. FDA-approved for T2DM and obesity. Titrate dose slowly to minimize GI side effects. | Dual GIP/GLP-1 receptor agonist. Significantly reduces body weight through appetite suppression, slowed gastric emptying, and improved insulin sensitivity. Approved for T2DM and obesity management. | | Commonly reported | The constant background thoughts about food ("food noise") go quiet and portions shrink without effort, with nausea worst in the first days after each dose step. FDA-approved for type 2 diabetes, weight management, heart-risk reduction and MASH, with about 15% average weight loss at 68 weeks in its main trial. | Very strong appetite suppression and meals ending early, with nausea or tiredness for a day or two after the injection, mostly after dose increases. FDA-approved for diabetes (Mounjaro) and for weight management and sleep apnea (Zepbound). | | Studied range | FDA label: 0.25–2.4 mg, starting dose 0.25 mg. | FDA label: 2.5–15 mg, starting dose 2.5 mg. | | How often | Weekly SubQ | Weekly | | Half-life | ~1 week (FDA label) | ~5 days (FDA label) | | Route | SubQ injection | SubQ injection | | Typical run | FDA-approved for ongoing use. Community uses indefinitely or until goal weight reached, then tapers. | FDA-approved for ongoing use. Titrate slowly upward. Community maintains on minimum effective dose. | | Evidence | Established: clinical trials or FDA-approved use exists | Established: clinical trials or FDA-approved use exists | | Common side effects | Nausea, vomiting, diarrhea, constipation, decreased appetite, fatigue, pancreatitis risk | Nausea, diarrhea, vomiting, constipation, abdominal pain, decreased appetite, fatigue | Typical run: Community practice — opinions vary. Not a clinical recommendation. ## Week by week Each entry’s cards by day window, as the compound pages show them. Day 1 is the day you start it. ### Semaglutide - Day 1–28 · 0.25 mg Gut is adapting - Day 29–56 · 0.5 mg Appetite shifts are real now - Day 57–112 · 1 mg Clinically useful weight loss kicks in - Day 113–140 · 1.7 mg Max submaximal step - Day 141–364 · 2.4 mg Full dose — the working dose - Day 365+ Plateau territory — new baseline [Every card for semaglutide, with its sources](https://pepvault.app/peptides/semaglutide#weeks) ### Tirzepatide - Day 1–28 · 2.5 mg Getting your gut acclimated - Day 29–56 · 5 mg First therapeutic dose — weight drops - Day 57–112 · 7.5 mg Dual agonism in full effect - Day 113–168 · 12.5 mg Max titration reached - Day 169–504 Weeks 24 to 72: where most people plateau - Day 365+ A maintenance medication, not a course [Every card for tirzepatide, with its sources](https://pepvault.app/peptides/tirzepatide#weeks) ## Together or one or the other The library marks semaglutide and tirzepatide as not combined. ## Questions people ask ### How long do semaglutide and tirzepatide last? The half-life of semaglutide is ~1 week (FDA label). The half-life of tirzepatide is ~5 days (FDA label). ### How often are semaglutide and tirzepatide taken? Semaglutide: weekly SubQ. Route: SubQ injection. Tirzepatide: weekly. Route: SubQ injection. ### How are semaglutide and tirzepatide dosed in research? The FDA label range for semaglutide is 0.25–2.4 mg, with a 0.25 mg starting dose. The FDA label range for tirzepatide is 2.5–15 mg, with a 2.5 mg starting dose. ### What are the common side effects of semaglutide and tirzepatide? For semaglutide, the library lists: nausea, vomiting, diarrhea, constipation, decreased appetite, fatigue, pancreatitis risk. For tirzepatide: nausea, diarrhea, vomiting, constipation, abdominal pain, decreased appetite, fatigue. ### Are semaglutide and tirzepatide taken together? No. The library marks semaglutide and tirzepatide as not combined. ## Each one in full - [Semaglutide: dosage, half-life & reference guide](https://pepvault.app/peptides/semaglutide) - [Tirzepatide: dosage, half-life & reference guide](https://pepvault.app/peptides/tirzepatide) - [Semaglutide dose guide](https://pepvault.app/lab/dosage/semaglutide) - [Tirzepatide dose guide](https://pepvault.app/lab/dosage/tirzepatide) PepVault for iPhone ## Track either one in PepVault Log every dose of semaglutide or tirzepatide, with reminders on your schedule. 7 days free on the yearly plan for new subscribers. [Download on the App Store](https://apps.apple.com/app/apple-store/id6779318649?pt=129020030&ct=compound-vs-band&mt=8) [Explore the live demo](https://pepvault.app/login) ## More comparisons - [All peptide comparisons](https://pepvault.app/peptides/compare) - [Retatrutide vs Tirzepatide](https://pepvault.app/peptides/compare/retatrutide-vs-tirzepatide) - [Retatrutide vs Semaglutide](https://pepvault.app/peptides/compare/retatrutide-vs-semaglutide) - [Mazdutide vs Tirzepatide](https://pepvault.app/peptides/compare/mazdutide-vs-tirzepatide) - [Orforglipron vs Semaglutide](https://pepvault.app/peptides/compare/orforglipron-vs-semaglutide) - [Cagrilintide vs Semaglutide](https://pepvault.app/peptides/compare/cagrilintide-vs-semaglutide) - [Liraglutide vs Semaglutide](https://pepvault.app/peptides/compare/liraglutide-vs-semaglutide) ## The library - [The peptide reference library](https://pepvault.app/peptides) - [Metabolic & GLP-1 peptides](https://pepvault.app/peptides#metabolic) ## Free tools - [The Dose Guide](https://pepvault.app/lab/dosage) - [Half-life & active level](https://pepvault.app/tools/peptide-half-life-calculator) - [Reconstitution calculator](https://pepvault.app/tools/reconstitution-calculator) - [GLP-1 titration planner](https://pepvault.app/tools/glp1-titration-calculator) PepVault is a research and tracking resource, not medical advice. Ranges are what studies used, never a dose for you. Brand names are trademarks of their owners; PepVault is independent of them. PepVault is a private research and tracking tool, not medical advice. The information here is reference material from published literature and community use — always verify it and discuss any protocol with a qualified clinician before changing it. Ozempic, Wegovy, Rybelsus, Mounjaro, Zepbound, Saxenda, Victoza and Trulicity are trademarks of their respective owners; PepVault is independent and not affiliated with or endorsed by any manufacturer. © 2026 PepVault