Quick answer: there is no official GLP-1 dose conversion chart between different drugs. FDA labels give exact conversions only within a brand family, such as Wegovy 2.4 mg injection to Wegovy 25 mg tablets, or Ozempic 0.5 mg injection to Rybelsus 7 or 14 mg.[1][3] Switching from semaglutide to tirzepatide, or from dulaglutide to either, relies on label starting doses (Mounjaro and Zepbound start at 2.5 mg) plus modeling studies and expert opinion.[4][5][9][10]
Your prescriber sets the dose. This page explains what each source says so you can follow the conversation. For the drugs themselves, see our profiles of semaglutide, tirzepatide, liraglutide and dulaglutide, or the GLP-1 basics hub.
Why there is no official conversion
GLP-1 drugs differ in how they work, how long they last and how strong each milligram is. Tirzepatide acts on both GIP and GLP-1 receptors; semaglutide, liraglutide and dulaglutide act on GLP-1 only. A milligram of one is not a milligram of another.
Even within semaglutide, the oral and injected forms are not interchangeable. The tablet label states that Rybelsus and Ozempic tablets “are not substitutable on a mg-to-mg basis.”[3] The authors of the most-cited switching guidance said their dose choices were “entirely based on authors’ opinion.”[10]
GLP-1 dose conversion chart
The Basis column tells you where each row comes from. “Label” means the instruction is printed in the FDA prescribing information. “Study estimate” means it comes from published modeling, trials or expert opinion and is not an official conversion.
| Switching from | Switching to | What the source says | Basis |
|---|---|---|---|
| Wegovy 2.4 mg injection | Wegovy tablets | Start 25 mg daily one week after the last injection | Label[1] |
| Wegovy 25 mg tablets | Wegovy injection | Start 2.4 mg weekly the day after the last tablet (1.7 mg if 25 mg was not tolerated) | Label[1] |
| Ozempic 0.5 mg injection | Rybelsus or Ozempic tablets | One week later, start Rybelsus 7 or 14 mg, or Ozempic tablets 4 or 9 mg | Label[3] |
| Rybelsus 7 mg / 14 mg | Ozempic tablets | 4 mg / 9 mg, starting the next day (not during the first 30 days) | Label[3] |
| Any GLP-1 drug | Mounjaro or Zepbound | Label starting dose 2.5 mg weekly for 4 weeks, then up 2.5 mg every 4+ weeks | Label starting dose[4][5] |
| Any GLP-1 drug | Ozempic or Wegovy injection | Label starting dose 0.25 mg weekly for 4 weeks | Label starting dose[1][2] |
| Any GLP-1 drug | Trulicity | Label starting dose 0.75 mg weekly | Label starting dose[6] |
| Semaglutide 0.5 to 2 mg, or dulaglutide | Tirzepatide | Modeling predicted further HbA1c and weight reduction even at 5 mg | Study estimate[9] |
| Semaglutide 2.4 mg / 7.2 mg | Tirzepatide | Weight-loss effect statistically similar to tirzepatide 10 mg / 15 mg | Study estimate[15] |
| Weekly drug, max dose tolerated | Ozempic | Start 0.5 mg one week after the last dose, then 1 mg after 4 weeks | Study estimate (expert opinion)[10] |
| Daily liraglutide (Victoza, Saxenda) | Weekly drug | Start the day after the last daily dose | Study estimate (expert opinion)[10] |
Label starting doses are designed to reduce stomach side effects, not to match your previous dose. The 2.5 mg dose of Zepbound “is for treatment initiation and is not approved as a maintenance dosage.”[5]
Ozempic or Wegovy to Mounjaro or Zepbound
This is the most common switch, and the one with the least official guidance. Neither tirzepatide label mentions people coming from semaglutide; both say to start at 2.5 mg and step up in 2.5 mg increments after at least 4 weeks.[4][5]
What the studies add:
- Lilly modeling study (2024): simulated people on semaglutide or dulaglutide moving to tirzepatide. Switching to any tirzepatide maintenance dose, including 5 mg, was predicted to lower HbA1c and weight further. It is a computer model built from trial data, written by Lilly scientists, and was not a clinical trial.[9]
- Novo-funded modeling study (2026): in type 2 diabetes trial data, semaglutide 2.4 mg and tirzepatide 10 mg had a 99.4% probability of similar weight loss, and semaglutide 7.2 mg versus tirzepatide 15 mg had 94.8%. Lower semaglutide doses were not equivalent to higher tirzepatide doses.[15]
- Small real-world study: 15 people with type 2 diabetes switched from semaglutide 1 mg to tirzepatide, all starting at 2.5 mg. Those who reached 10 mg within 3 months had a significant HbA1c drop; those at 7.5 mg did not.[14]
Mounjaro or Zepbound back to semaglutide
No label or trial gives a tirzepatide-to-semaglutide conversion. The Ozempic and Wegovy labels start at 0.25 mg weekly for 4 weeks, then step up monthly.[1][2] A prescriber may use the 2026 equivalence estimates above in reverse, but that study looked at average weight loss in groups, not individual switches.[15]
Trulicity to Ozempic or Mounjaro
Dulaglutide (Trulicity) has the best switching evidence because of a randomized trial. In SURPASS-SWITCH, 282 adults on Trulicity 0.75 or 1.5 mg either raised their Trulicity dose or switched to tirzepatide.[13] Those switched started tirzepatide at 2.5 mg and stepped up every 4 weeks. At 40 weeks:[13]
| Outcome | Switched to tirzepatide | Stayed on higher Trulicity |
|---|---|---|
| HbA1c change | −1.44% | −0.67% |
| Weight change | −10.5 kg | −3.6 kg |
| Serious adverse events | 7.2% | 7.0% |
The trial was open-label and funded by Lilly, which makes both drugs.[13]
For Trulicity to Ozempic, expert guidance suggests stopping Trulicity and starting Ozempic one week later on the same weekday. People who tolerated their Trulicity dose well may start at 0.5 mg; those with stomach side effects should wait until symptoms settle and start at 0.25 mg.[10] Trulicity’s own label tops out at 4.5 mg weekly.[6]
Daily liraglutide to a weekly drug
Victoza (up to 1.8 mg daily) and Saxenda (3 mg daily) are daily liraglutide injections.[7][8] Published guidance suggests starting the weekly drug the day after the last daily dose; for semaglutide, that means 0.5 mg for 4 weeks if the top liraglutide dose was tolerated, or 0.25 mg if it was not.[10]
A 2021 expert consensus adds that the choice should depend on the previous dose, how long you took it, how you handled the first weeks of treatment and your other medicines.[11] See our liraglutide vs semaglutide comparison for how they differ.
Rough potency ranking
A 2024 research letter ranked GLP-1 drugs by how much they lowered HbA1c and weight in type 2 diabetes trials. Higher-dose dulaglutide (3 and 4.5 mg), semaglutide 1 and 2 mg, and every tirzepatide maintenance dose (5 mg and up) lowered HbA1c by at least 1.5%. Only semaglutide and tirzepatide consistently reduced weight by 5 kg or more. The authors noted these comparisons were not head-to-head trials.[12]
Before you switch
- Timing: for weekly drugs, start the new one when your next weekly dose would be due.[10]
- Missed-dose windows differ: Ozempic allows a missed dose within 5 days; Mounjaro and Zepbound within 4 days; Trulicity if at least 3 days remain before the next dose.[2][4][6] See missed GLP-1 dose.
- Side effects can return: nausea and other stomach effects may come back after a switch, which is why labels start low.[11]
- Birth control: tirzepatide labels advise people using oral contraceptives to add or switch to a non-oral method for 4 weeks after starting and after each dose increase.[4][5]
If a switch is because weight loss stalled, see not losing weight on a GLP-1. For drug-specific schedules, see the semaglutide dosage chart, the tirzepatide dosage chart and our semaglutide vs tirzepatide comparison. If you are thinking of stopping instead, read stopping a GLP-1.
