Tirzepatide vs semaglutide for weight loss
You are deciding between two options.
Reference and calculator, not medical advice. Dosing figures below are transcribed from FDA-approved prescribing information and link back to it. Last reviewed August 2026.
Both are labelled for long-term weight management, which makes this one of the few comparisons on this site where the two sides genuinely occupy the same role. The structural differences are documented; the question of which produces more weight loss for you is not one this site answers.
Side-by-side
Structural facts from each product’s prescribing information.
| Product | Active ingredient | Indication | Frequency | Start | Max labelled | Steps to max |
|---|---|---|---|---|---|---|
| Zepbound Eli Lilly | Tirzepatide | Weight management | Weekly | 2.5 mg | 15 mg | 6 |
| Wegovy Novo Nordisk | Semaglutide | Weight management | Weekly | 0.25 mg | 2.4 mg | 5 |
| Wegovy tablets Novo Nordisk | Semaglutide (oral) | Weight management | Daily | 1.5 mg | 25 mg | 4 |
Mechanism is the first real difference. Semaglutide's label describes it as a GLP-1 analogue with 94% sequence homology to human GLP-1. Tirzepatide's describes it as "a GIP receptor and GLP-1 receptor agonist" — a second target, with the label noting cautiously that nonclinical studies suggest GIP may further contribute to the regulation of food intake.
The second is the escalation path. Tirzepatide runs six steps from 2.5 mg to 15 mg; Wegovy injection runs five from 0.25 mg to 2.4 mg. More steps means smaller increments, which changes what titration feels like rather than where it ends up.
Zepbound titration schedule
Tirzepatide · once weekly · subcutaneous injection · as published in the prescribing information
| Step | Dose | Notes |
|---|---|---|
| Weeks 1–4 | 2.5 mg | Starting dose — not intended for weight loss effect |
| Weeks 5–8 | 5 mg | — |
| Weeks 9–12 | 7.5 mg | — |
| Weeks 13–16 | 10 mg | — |
| Weeks 17–20 | 12.5 mg | — |
| Week 21+ | 15 mg | Maximum dose |
This is the labelled default. Holding at a step longer than shown is common practice and is a decision for your prescriber. Transcribed from the Zepbound prescribing information (label revised 6 May 2026); checked against that label on 7 August 2026.
Wegovy titration schedule
Semaglutide · once weekly · subcutaneous injection · as published in the prescribing information
| Step | Dose | Notes |
|---|---|---|
| Weeks 1–4 | 0.25 mg | Starting dose |
| Weeks 5–8 | 0.5 mg | — |
| Weeks 9–12 | 1 mg | — |
| Weeks 13–16 | 1.7 mg | — |
| Week 17+ | 2.4 mg | Maintenance dose |
This is the labelled default. Holding at a step longer than shown is common practice and is a decision for your prescriber. Transcribed from the Wegovy prescribing information (label revised 30 June 2026); checked against that label on 7 August 2026.
A warning about the milligram numbers: they are not comparable. These are different molecules on different scales, roughly a factor of six apart, and 5 mg of one is not a stronger or weaker dose than 5 mg of the other. Each product's schedule is only meaningful against itself.
Cost comparison calculator
Enter the quotes you have actually been given. Everything is normalised to cost per month and cost per milligram so the options are comparable.
| Option | Per month | Per year | Per mg | One unit lasts |
|---|---|---|---|---|
| Option A | — | — | — | — |
| Option B | — | — | — | 2.0 weeks |
Common questions
- Which one causes more weight loss?
- Head-to-head efficacy is outside what this site publishes. Both labels contain trial results, both are worth reading, and how either performs for one person is a prescriber conversation rather than a table lookup.
- Is the dual mechanism definitely better?
- The label itself hedges — it cites nonclinical studies and says GIP "may" further contribute. That is deliberately cautious language from the manufacturer about its own product, and it is worth reading as written.
- Can I switch between them?
- A prescriber decision, and the labelling advises against using GLP-1 receptor agonists concurrently. Dose does not carry across — a switch restarts at the new product’s own starting step.
Sources and last review
Every dosing figure on this page is transcribed from an FDA-approved label and links back to it. Conversions are arithmetic you can repeat by hand. Nothing here is reviewed by a clinician, and this site does not employ one — which is exactly why what I do publish stays traceable to its source.
- Zepbound (Tirzepatide) prescribing information — Eli Lilly, label revised 6 May 2026, checked 7 August 2026
- Wegovy (Semaglutide) prescribing information — Novo Nordisk, label revised 30 June 2026, checked 7 August 2026
Transcribed from the labels above and checked by me — Gavin, who builds this site, takes a GLP-1, and is not a clinician. Last reviewed August 2026. Found an error? [email protected] — I treat corrections as bugs. How this site is built and funded.
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