Switching From Wegovy to Zepbound: Doses, Timing, and What to Expect
There is no official Wegovy-to-Zepbound conversion. The Zepbound label says every patient starts at 2.5 mg weekly for 4 weeks, with no exception for people coming from another GLP-1, and neither label specifies a washout — timing is your prescriber's call.
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Switching from Wegovy to Zepbound is common, but there is no official dose conversion between the two drugs. The Zepbound (tirzepatide) prescribing label gives one starting schedule for everyone: 2.5 mg injected once weekly for 4 weeks, then an increase to 5 mg weekly, with further 2.5 mg increases after at least 4 weeks at each dose [2]. The label contains no exception, shortcut, or alternate starting dose for people transferring from Wegovy or any other GLP-1 medication [2]. Neither the Zepbound nor the Wegovy label specifies a washout period between the two drugs — both labels only say that taking them together is not recommended [2][4]. How long to wait, and what dose you actually start at, are decisions for your prescriber.
This page walks through what the labels say, what published clinician guidance and research show about dose equivalence and timing, and what real-world studies found in people who made this exact switch. Nothing here is medical advice — your dose and your switch timing are decisions you make with your prescriber.
Why do people switch from Wegovy to Zepbound?
Switching between GLP-1 medications is a normal part of treatment for many people, not a sign that something went wrong. In a large private healthcare network in Poland, researchers looked at GLP-1 prescription records from 2018 to 2025 covering 42,423 patients with more than one prescription. Of those patients, 29.7% switched agents at least once, and 14.3% switched two or more times [1]. In the detailed transition analysis, 12,620 patients contributed 27,095 prescription-to-prescription transitions [1]. The same study found accelerated tirzepatide uptake after it entered the market [1].
That study did not measure why people switched, and its authors describe their findings as hypothesis-generating rather than proof of cause [1]. Reasons commonly cited in clinical literature for switching between these drugs include adverse effects, patient preference, cost pressures, and formulary decisions — for example, when an insurer changes which drugs it covers [6].
Are Wegovy and Zepbound interchangeable milligram-for-milligram?
No. The two drugs are related but not the same molecule, and their milligram numbers do not mean the same thing.
Wegovy is semaglutide, a GLP-1 receptor agonist [4]. Zepbound is tirzepatide, which acts on both the GIP receptor and the GLP-1 receptor [2]. Because of those differing receptor profiles, there is no validated dose equivalence between semaglutide and tirzepatide [6]. Tirzepatide’s GIP activity may amplify weight loss through pathways that GLP-1 agonism alone does not replicate [6].
Semaglutide also stays in the body a long time — its half-life is roughly 165 to 184 hours, which is what allows once-weekly dosing [6]. That long half-life is one reason the question of overlap and washout comes up when switching, covered below.
For context on where you are now: the Wegovy injection label says to initiate at 0.25 mg once weekly for 4 weeks, titrate every 4 weeks, and the usual recommended maintenance dosage is 2.4 mg once weekly [4].
Is there an official Wegovy-to-Zepbound dose conversion chart?
No. The FDA-approved Zepbound label has no conversion chart and no alternate starting pathway for patients arriving from another GLP-1. Here is exactly what the label specifies [2]:
| Zepbound label schedule | What it says |
|---|---|
| Starting dosage (all indications) | 2.5 mg injected subcutaneously once weekly for 4 weeks [2] |
| Status of the 2.5 mg dose | For treatment initiation only; not approved as a maintenance dosage [2] |
| First increase | After 4 weeks, increase to 5 mg once weekly [2] |
| Further increases | 2.5 mg increments, after at least 4 weeks on the current dose [2] |
| Maintenance for weight reduction | 5 mg, 10 mg, or 15 mg once weekly [2] |
| Maintenance for obstructive sleep apnea | 10 mg or 15 mg once weekly [2] |
| Maximum dosage | 15 mg once weekly [2] |
The label states that this escalation schedule exists to reduce the risk of gastrointestinal adverse reactions, and that prescribers should consider treatment response and tolerability when selecting the maintenance dosage — including considering a lower maintenance dosage if a dose is not tolerated [2].
One published clinician reference does offer a comparative dose chart, but it has important limits. Beth Israel Lahey Health (BILH) publishes a GLP-1RA conversion guide, updated in August 2024 and adapted from a paper by Whitley HP in Clinical Diabetes (2023;41(3):467–473) [3]. It is not an FDA document. Its own header says it does not replace clinical judgment [3].
The BILH comparative row lists subcutaneous semaglutide weekly doses of 0.25/0.5/1/2 mg against tirzepatide weekly doses of 2.5/5/7.5/10/12.5/15 mg [3]. Its switching instructions say that if a switch is prompted by side effects, the clinician should start at the lowest available dose, titrate per product instructions, consider slower titration, and consider a lower maintenance dose; if the switch is prompted by other reasons, start with the equivalent dose, consider a lower dose if the patient had side effects during titration, and discontinue the current agent [3]. It also advises not switching from a submaximal dose of one agent to the maximum dose of another, and stepping down a dose when converting if the patient had prior GI side effects on GLP-1RAs [3]. Again: this is A1c-based guidance for diabetes brands, not a weight-loss equivalence tool, and not a rule for what your prescriber should do.
For completeness: the Wegovy label does have a dedicated switching section (section 2.5), but it covers only switching between Wegovy injection and Wegovy tablets — the same active substance — not switching to a different drug [4].
What does the dose-equivalence research actually show?
A model-based analysis published in Diabetes Therapy (2026;17(7):1067–1083) tried to quantify which semaglutide and tirzepatide doses produce comparable weight loss [5]. The researchers pooled arm-level data from phase III trials of semaglutide (SUSTAIN, STEP) and tirzepatide (SURPASS, SURMOUNT-2) — 48 treatment arms and 16,524 participants, all in type 2 diabetes populations [5]. They used Bayesian hierarchical spline models and defined equivalence as within ±2 percentage points of weight change [5].
Two dose pairs stood out: semaglutide 2.4 mg versus tirzepatide 10 mg had a 99.4% probability of equivalence, and semaglutide 7.2 mg versus tirzepatide 15 mg had a 94.8% probability [5]. Lower semaglutide doses were not equivalent to higher tirzepatide doses [5]. Both drugs showed nonlinear dose–response, meaning the extra benefit from each dose increase gets smaller at higher doses [5].
The authors’ conclusion was that equivalence is driven by dose rather than drug identity, and that this kind of modeling offers a framework for individualized decisions when direct comparative evidence is unavailable [5]. Two of the co-authors are affiliated with Novo Nordisk, the maker of Wegovy [5].
Two caveats about this study. First, every participant had type 2 diabetes, so the numbers do not directly apply to people taking these drugs for weight loss without diabetes. Second, the only true head-to-head trial of the two drugs (SURMOUNT-5) was conducted in obesity without type 2 diabetes and used maximum tolerated doses rather than the full dose range [5]. The modeling study does not tell you what dose to start at — that remains a prescriber decision.
How long should I wait between the last Wegovy shot and the first Zepbound shot?
Neither US label specifies a washout period. What both labels do say is that the drugs should not be taken together. Zepbound’s Limitations of Use state that coadministration with other tirzepatide-containing products or with any GLP-1 receptor agonist is not recommended [2]. Wegovy’s Limitations of Use say the same thing in reverse: concomitant use with other semaglutide-containing products or any other GLP-1 receptor agonist is not recommended [4].
Published pharmacist guidance lays out two approaches clinicians use, and the choice depends on the patient [6]:
- A washout of one to two weeks before starting the new drug, which the guidance says is preferred where the patient had significant side effects [6].
- A same-day switch, meaning the new drug starts on the next scheduled dose day, which the guidance says can be considered for stable, tolerating patients where the clinician judges the risk of heightened side effects to be low [6].
The same guidance notes the trade-off on both sides: because both drugs have long half-lives and overlapping activity, taking them concurrently could heighten side effects — but a prolonged gap off medication may cause rebound appetite and worse glycemic control [6]. It also says a washout should be considered when moving between injection and oral formulations, and that a shorter or longer washout should be thoughtfully justified based on the patient’s medical history and treatment response so far [6]. That guidance recommends clinical monitoring and a documented justification for whichever approach is chosen [6].
There is no single right answer published anywhere, and this page is not telling you which gap is right for you. Your prescriber decides the timing based on your history and how you tolerated Wegovy.
Do I have to start over on Zepbound?
In practical terms, starting Zepbound means going through its titration schedule from the beginning: at least 4 weeks at 2.5 mg before 5 mg, and at least 4 weeks at each 2.5 mg step after that [2]. The label offers no provision for skipping steps based on prior GLP-1 exposure [2].
Whether that feels like “starting over” depends on your perspective. The label’s escalation schedule exists specifically to reduce the risk of gastrointestinal adverse reactions [2], and published guidance notes that both agents require gradual titration to mitigate GI symptoms, and that deviating from standard titration can increase adverse effects [6]. The same guidance notes tirzepatide’s broader receptor activity may contribute to slightly higher early GI intolerance compared with semaglutide, though discontinuation rates have been comparable [6].
If you reach a maintenance dosage and do not tolerate it, the Zepbound label instructs prescribers to consider a lower maintenance dosage [2].
What should I expect in the first weeks after switching?
The most common adverse reactions reported in at least 5% of patients treated with Zepbound are: nausea, diarrhea, vomiting, constipation, abdominal pain, dyspepsia, injection site reactions, fatigue, hypersensitivity reactions, eructation (burping), hair loss, and gastroesophageal reflux disease [2]. Much of this list overlaps with Wegovy’s common reactions, which include nausea, diarrhea, vomiting, constipation, abdominal pain, dyspepsia, dizziness, headache, fatigue, and hair loss, among others [4].
The Zepbound label specifies its step-by-step escalation schedule — 4 weeks at 2.5 mg, then 5 mg, then 2.5 mg increases after at least 4 weeks at each dose — in order to reduce the risk of gastrointestinal adverse reactions [2]. How you tolerated Wegovy titration is one of the pieces of information clinicians use when planning a switch — guidance on switching says the prior agent and dose, tolerability during titration, and prior GI side effects all inform the approach [3][6].
Will Zepbound work if I stalled on Wegovy?
A real-world study published in Obesity (2026) looked directly at people who switched from semaglutide to tirzepatide. It was a retrospective cohort of adults treated with tirzepatide between May 2022 and January 2023, tracking 6-month outcomes; of 941 charts reviewed, 293 (31.1%) met inclusion criteria — 65% female, mean age 52, mean BMI 36.15 kg/m² [8].
A “switch from therapeutic semaglutide” was defined as having taken at least 1.7 mg weekly for at least one month [8]. Among the 61 patients who switched due to non-response or plateau, average loss on tirzepatide was 5.3% of total body weight [8]. But the two groups did very differently: patients who switched at a plateau (n=28) lost 8.1% of total body weight, while non-responders (n=33) lost 2.9% (p<0.001) [8]. In that study, non-response was defined as less than 5% weight loss after at least 3 months, and plateau as at least 5% loss followed by weight stabilization [8].
The study also compared people by prior weight loss: patients who had already lost at least 10% of their total body weight before starting tirzepatide (n=133) lost 7.2% on tirzepatide, versus 10.3% in those who were not weight-reduced (n=160), a statistically significant difference [8]. The authors’ conclusion was that tirzepatide produced meaningful weight loss across groups, but outcomes varied based on weight-reduction status, diabetes status, and prior response to semaglutide [8].
The short version: in that cohort, people who plateaued on semaglutide tended to lose more after switching than people who never responded at all — but these are group averages, not a prediction for any one person.
Is Zepbound stronger than Wegovy for weight loss?
On average across trial populations, yes — but averages are not guarantees for an individual.
In the SURMOUNT-5 head-to-head randomized trial, mean weight loss at 72 weeks was −20.2% (95% CI −21.4 to −19.1) with tirzepatide versus −13.7% (95% CI −14.9 to −12.6) with semaglutide (P<0.001) [6]. A large US real-world cohort of roughly 18,000 patients found people on tirzepatide were more likely to reach ≥5%, ≥10%, and ≥15% weight loss than people on semaglutide (hazard ratios 1.76, 2.54, and 3.24 respectively), with a 12-month mean weight difference of −6.9% [6]. Head-to-head data published in 2024 showed no significant difference in serious adverse events between the two [6].
Those are population means. Individual results depend on dose, adherence, tolerability, and factors no trial can average away — which is part of why the Zepbound label tells prescribers to consider treatment response and tolerability when selecting a maintenance dosage [2].
What if I miss doses during the switch because of supply or coverage gaps?
Insurance changes and shortages sometimes force a gap between stopping one drug and starting another. Both labels have missed-dose sections — Zepbound section 2.3 and Wegovy section 2.4 — but the specific rules within those sections are not reproduced here, so check the label or ask your pharmacist for the exact missed-dose instructions [2][4].
The BILH guide does publish resumption suggestions for therapy lapses, again adapted from the Whitley Clinical Diabetes paper and framed for diabetes brands [3]. For subcutaneous semaglutide at a last dose of 1 mg weekly: if 2 or fewer doses were missed, reinitiate at 1 mg; if 3–4 doses were missed, reinitiate at 0.5 mg; if 5 or more were missed, reinitiate at 0.25 mg [3]. For tirzepatide at a last dose of 5 mg weekly or higher: if fewer than 2 doses were missed, resume the same dose if it was previously tolerated; if 3 or more were missed, reinitiate at 5 mg, or 2.5 mg if there is concern about GI side effects [3]. These are clinician reference points, not instructions for you to follow on your own.
One published case report describes severe gastrointestinal intolerance after a patient resumed maintenance-dose semaglutide following a Ramadan-related treatment interruption [11].
What safety information carries over from Wegovy to Zepbound?
Most of the major warnings are shared between the two labels, so the safety picture does not reset when you switch:
- Both drugs carry a boxed warning about thyroid C-cell tumors seen in rats and rodents, and both are contraindicated in people with a personal or family history of medullary thyroid carcinoma (MTC) or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) [2][4].
- Zepbound is not recommended in patients with severe gastroparesis [2].
- Zepbound’s warnings include acute kidney injury from volume depletion, acute gallbladder disease, acute pancreatitis, hypersensitivity reactions, hypoglycemia when used with insulin or an insulin secretagogue, progression of diabetic retinopathy, and pulmonary aspiration during general anesthesia or deep sedation [2].
- Zepbound delays gastric emptying and can affect the absorption of oral medications taken alongside it [2].
- The Zepbound label advises females using oral contraceptives to switch to a non-oral method or add a barrier method for 4 weeks after initiation and for 4 weeks after each dose escalation [2].
- The Wegovy label says to discontinue the drug at least 2 months before a planned pregnancy, because of semaglutide’s long half-life [4].
- Neither pen should ever be shared between patients: the Zepbound KwikPen and the Wegovy FlexTouch each carry a “never share” warning, even with a changed needle [2][4].
If you have surgery planned, both labels instruct patients to tell their healthcare providers about planned procedures, because of the pulmonary aspiration warning [2][4].
What will the Zepbound prescription look like compared with Wegovy?
The dose forms differ in detail. Zepbound comes as a single-dose pen or single-dose vial in strengths of 2.5, 5, 7.5, 10, 12.5, or 15 mg per 0.5 mL, and as a multi-dose vial or single-patient-use KwikPen in 10, 20, 30, 40, 50, or 60 mg per 2.4 mL, each delivering four doses [2].
Wegovy injection comes in single-dose pens at 0.25, 0.5, 1, 1.7, and 2.4 mg, plus 7.2 mg (Wegovy HD), with a FlexTouch pen at 9.6 mg/3 mL that delivers four 2.4 mg doses [4]. Wegovy tablets exist at 1.5, 4, 9, and 25 mg, started at 1.5 mg daily and titrated every 30 days [4].
| Wegovy (semaglutide) | Zepbound (tirzepatide) | |
|---|---|---|
| Drug class | GLP-1 receptor agonist [4] | GIP receptor + GLP-1 receptor agonist [2] |
| Injection strengths | 0.25, 0.5, 1, 1.7, 2.4 mg; 7.2 mg (HD); FlexTouch 9.6 mg/3 mL (four 2.4 mg doses) [4] | 2.5, 5, 7.5, 10, 12.5, 15 mg per 0.5 mL; multi-dose 10–60 mg per 2.4 mL (four doses each) [2] |
| Label starting dose | 0.25 mg once weekly for 4 weeks [4] | 2.5 mg once weekly for 4 weeks [2] |
| Usual maintenance (weight) | 2.4 mg once weekly [4] | 5 mg, 10 mg, or 15 mg once weekly [2] |
| Maximum dosage | Not stated as a single maximum in the label excerpt; usual maintenance is 2.4 mg once weekly, with a 7.2 mg (Wegovy HD) strength available [4] | 15 mg once weekly [2] |
What should I bring up with my prescriber?
The information that published guidance says should drive dose and approach decisions is concrete: your prior agent and dose, how well you tolerated titration, and any GI side effects you had on GLP-1 medications before [3][6]. The pharmacist guidance also recommends clinical monitoring during the switch and a documented rationale for the approach chosen [6]. BILH advises counseling patients on the differences between agents at the time of the switch [3].
Useful questions to ask include: what starting dose and titration pace the prescriber plans for you and why; whether they want a gap between your last Wegovy shot and your first Zepbound shot, and how long; what side effects would prompt a call; and how your response and tolerability will factor into which maintenance dosage you land on — the consideration the Zepbound label itself names [2].
Who decides the dose and the timing?
Your prescriber does. Everything on this page is a summary of what the FDA labels say and what published research and clinician guidance report — it is not medical advice, and no published source establishes one correct starting dose, washout length, or titration plan for a person moving from Wegovy to Zepbound. If you are switching because of an insurance formulary change, a shortage, side effects, or a weight-loss plateau, the specifics of your transition should be worked out with the clinician writing the prescription.
Sources
- PubMed. Switching patterns of GLP-1 receptor agonists from 2018 to 2025 in the largest private healthcare network in Poland.
- Eli Lilly and Company. ZEPBOUND (tirzepatide) injection, for subcutaneous use: prescribing information.
- Beth Israel Lahey Health. GLP-1RA and dual GLP-1RA/GIP: conversions and therapy gap management guide. August 2024.
- Novo Nordisk. WEGOVY (semaglutide) injection: prescribing information.
- PubMed Central. Dose-response and clinical equivalence of semaglutide and tirzepatide for weight loss in type 2 diabetes: a model-based analysis.
- The Pharmaceutical Journal. Switching between weight-loss medications.
- Endocrine Practice. Switching to tirzepatide 5 mg from glucagon-like peptide-1 receptor agonists: clinical expectations in the first 12 weeks of treatment. August 2024.
- PubMed. Real-world weight-loss outcomes in weight-reduced patients treated with tirzepatide.
- PubMed. Real-world semaglutide in obesity cohort: effectiveness, safety and persistence across sex, BMI, and prior GLP-1RA treatment.
- Eli Lilly and Company. Zepbound (tirzepatide) dosing: dosage options, schedules and missed doses.
- PubMed. Severe gastrointestinal intolerance after resuming maintenance-dose semaglutide following Ramadan-related treatment interruption: a case report.
- Mass.gov, Group Insurance Commission. CVS Caremark decides to remove Zepbound from CVS Caremark formulary.
- Managed Healthcare Executive. CVS Caremark to put Zepbound back on formulary and add Foundayo. May 28, 2026.
Frequently asked questions
Can you take Wegovy and Zepbound in the same week?
No. The Zepbound label states that coadministration with any GLP-1 receptor agonist, which includes Wegovy, is not recommended, and the Wegovy label says the same in reverse. Published pharmacist guidance describes either a one-to-two-week washout or a same-day switch onto the new drug — never overlapping doses — with the choice left to the clinician.
Do I start Zepbound at 2.5 mg even if I was on Wegovy 2.4 mg?
The Zepbound label gives one starting dosage for all patients and all indications: 2.5 mg injected once weekly for 4 weeks, and it contains no exception for people transferring from another GLP-1. The 2.5 mg dose is for initiation only and is not an approved maintenance dosage. Your prescriber makes the final call on your actual regimen.
What dose of Zepbound equals Wegovy 2.4 mg?
There is no validated dose equivalence between semaglutide and tirzepatide because of their different receptor profiles. A model-based analysis in type 2 diabetes populations found a 99.4% probability of equivalence for weight loss between semaglutide 2.4 mg and tirzepatide 10 mg, but that is research modeling, not a dosing rule, and it does not apply to people without type 2 diabetes.
How many weeks until I reach a Zepbound maintenance dose?
Following the label schedule, you spend 4 weeks at 2.5 mg, then move to 5 mg, with further 2.5 mg increases allowed only after at least 4 weeks on each dose. Maintenance dosages for weight reduction are 5 mg, 10 mg, or 15 mg weekly, so reaching 5 mg takes about 4 weeks, and each higher step adds at least 4 more.
Will I regain weight during the switch?
No study cited here measured weight change during the gap itself. Pharmacist guidance notes that prolonged discontinuation of these drugs may cause rebound appetite and worse glycemic control, which is one reason clinicians weigh washout length carefully. In a real-world cohort, patients who switched from semaglutide to tirzepatide at a plateau lost an average 8.1% of total body weight over 6 months.
Is Zepbound stronger than Wegovy for weight loss?
On average, yes. In the 72-week SURMOUNT-5 head-to-head trial, tirzepatide produced −20.2% mean weight loss versus −13.7% for semaglutide (P<0.001). A US real-world cohort of about 18,000 patients found tirzepatide more likely to achieve ≥5%, ≥10%, and ≥15% loss, with a 12-month mean difference of −6.9%. These are population averages, not individual guarantees.
What if I stalled on Wegovy — will Zepbound still work?
One real-world study reported group results for exactly this situation. Patients who switched from therapeutic semaglutide at a plateau lost 8.1% of total body weight on tirzepatide over 6 months, versus 2.9% for those who switched due to non-response (p<0.001). Outcomes varied by prior weight loss, diabetes status, and prior response, and group averages do not predict any individual result.
How long should the gap be between my last Wegovy shot and my first Zepbound shot?
Neither US label specifies a washout period; both only say the two drugs should not be taken together. Pharmacist guidance describes two clinician options — a one-to-two-week washout, preferred where side effects occurred, or a same-day switch for stable, tolerating patients — with the length justified case by case. Your prescriber decides your timing.
This article summarizes FDA labeling, published research and company information current as of September 14, 2026. It is not medical advice and does not replace a conversation with your own healthcare provider. How we research and verify.