Interactive tool · FDA prescribing information anchored
Brand-Switch Dose-Equivalence Calculator
Switching from one weight-loss GLP-1 drug to another? This tool surfaces the FDA-label dose ladders, re-titration rules, and cross-trial efficacy data for all four FDA-approved chronic-weight-management GLP-1 medications — Wegovy, Zepbound, Foundayo, and Saxenda — so you walk into your prescriber appointment better informed.
Medical disclaimer — read before using this tool
This tool does not provide medical advice. It is a patient-education aid that surfaces verbatim FDA-label dose information and published trial data. Brand-switch decisions — including starting dose, timing, and washout — must be made with and by a licensed prescriber. There is no FDA-approved dose-equivalence conversion between any of the four drugs listed here. Weight loss percentages are from independent phase 3 trials with different populations; they are not head-to-head equivalences. Compounded semaglutide and compounded tirzepatide are not FDA-approved; their dose ladders may differ from FDA-label doses.
Step 1 — Select your current drug and destination drug
Select your current drug above to unlock the destination selector.
About this tool
This tool covers the four FDA-approved medications indicated for chronic weight management in adults:
- Wegovy (semaglutide 2.4 mg weekly injection, Novo Nordisk) — FDA-approved June 2021; HD 7.2 mg tier approved September 2025
- Zepbound (tirzepatide weekly injection, Eli Lilly) — FDA-approved November 2023
- Foundayo (orforglipron once-daily oral tablet, Eli Lilly) — FDA-approved 2025
- Saxenda (liraglutide 3 mg daily injection, Novo Nordisk) — FDA-approved December 2014
Mounjaro (tirzepatide for T2D) and Ozempic (semaglutide for T2D) are not included because they carry a diabetes indication, not a primary obesity indication — their dose ladders are listed in the GLP-1 Titration Planner.
All dose ladders are sourced verbatim from FDA-approved prescribing information via DailyMed (NIH). DailyMed SetIDs: Wegovy (ee06186f-2aa3-4990-a760-757579d8f77b); Zepbound (487cd7e7-434c-4925-99fa-aa80b1cc776b); Foundayo (8ac446c5-feba-474f-a103-23facb9b5c62); Saxenda (3946d389-0926-4f77-a708-0acb8153b143).
Related tools
- GLP-1 Titration Schedule Planner — full week-by-week calendar for any start date
- GLP-1 Missed Dose Guide — per-drug FDA-label guidance
- GLP-1 Washout Calculator — how long your current drug stays in your system
- GLP-1 Decision Quiz — find the right drug for your profile
- GLP-1 Weight Loss Calculator — trial-anchored outcome projections
- GLP-1 Savings Calculator — compare monthly costs between drugs
Related research
- Foundayo ↔ Zepbound switch dose-equivalence guide (detailed article)
- Wegovy ↔ Zepbound switch guide — SURMOUNT-5 anchored
- Switching between GLP-1 medications — whole-class guide
- Foundayo vs Wegovy vs Zepbound full comparison
- Full GLP-1 medication list 2026 — every FDA-approved drug
- Weight loss injections guide 2026
- When to increase your Mounjaro dose for weight loss — titration decision guide
Medical disclaimer
This tool is for patient education only. It does not constitute medical advice, diagnosis, or a treatment recommendation. All brand-switch, dose, and timing decisions must be made with a licensed prescriber who can review your complete medical history, comorbidities, current medications, and insurance coverage. FDA-label dose ladders represent minimum titration intervals; your prescriber may individualize these based on tolerability. There is no FDA-approved dose-equivalence conversion between any of the four drugs in this tool. Cross-trial efficacy comparisons are not head-to-head data (except SURMOUNT-5 for Zepbound vs Wegovy). Compounded versions of semaglutide and tirzepatide are not FDA-approved products; consult your prescriber and compounding pharmacy for their specific dose ladders.