Zepbound to Wegovy Conversion Chart: The Evidence-Based Dose Translation Guide Providers Actually Use

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> Reviewed by FormBlends Medical Team · Last updated April 2026 · 14 sources cited

Key Takeaways

• No direct milligram-to-milligram conversion exists because tirzepatide (Zepbound) and semaglutide (Wegovy) work through different receptor mechanisms with different potency profiles
• The best available evidence suggests Zepbound 10 mg produces weight loss comparable to Wegovy 2.4 mg, making this the most common clinical conversion point
• Switching medications requires retitration in most cases, not a simple dose swap, because receptor occupancy and side effect profiles differ between the two drugs
• Insurance coverage changes, not clinical failure, drive most conversion requests, and the switch can be made without losing weight-loss momentum if done correctly

Direct answer (40-60 words)

There is no FDA-approved conversion chart between Zepbound (tirzepatide) and Wegovy (semaglutide) because they are different molecules with different mechanisms. Clinical trial data suggests Zepbound 10 mg produces weight loss similar to Wegovy 2.4 mg, but switching requires retitration starting at lower doses to minimize side effects, not a direct dose swap.

Table of contents

1. Why a simple conversion chart doesn't exist
2. The comparative efficacy data: what the trials actually show
3. The conversion framework providers use in practice
4. The retitration protocol for switching from Zepbound to Wegovy
5. The retitration protocol for switching from Wegovy to Zepbound
6. What most articles get wrong about GLP-1 conversion
7. When switching makes sense and when it doesn't
8. The insurance-driven conversion pattern we see most often
9. Side effects during the switch: what to expect
10. The dose-response curves are not parallel
11. Compounded tirzepatide to brand-name semaglutide conversions
12. FAQ
13. Sources

Why a simple conversion chart doesn't exist

Zepbound and Wegovy are not interchangeable medications with a fixed conversion ratio. They are different molecules that work through related but distinct mechanisms.

Tirzepatide (Zepbound) is a dual GLP-1 and GIP receptor agonist. Semaglutide (Wegovy) is a GLP-1 receptor agonist only. The addition of GIP agonism changes the pharmacodynamic profile in ways that make direct milligram-to-milligram conversion impossible.

Three reasons a simple chart is misleading:

1. Different receptor targets mean different potency curves. GLP-1 receptor activation drives most of the appetite suppression and gastric emptying delay. GIP receptor activation appears to enhance insulin secretion and may improve fat metabolism through mechanisms still being studied. The combined effect is not additive in a predictable way across doses.

2. Different half-lives. Semaglutide has a half-life of approximately 7 days. Tirzepatide has a half-life of approximately 5 days. This affects steady-state concentration, receptor occupancy over time, and how quickly side effects appear or resolve during titration.

3. Different dose-response relationships for weight loss vs glycemic control. In the SURMOUNT trials, tirzepatide showed a steep dose-response curve for weight loss between 5 mg and 15 mg. In the STEP trials, semaglutide showed a more gradual curve between 1.0 mg and 2.4 mg. The curves are not parallel, which means equivalence at one dose level does not predict equivalence at another.

The FDA has not published guidance on conversion between these medications because they are approved as separate therapies, not as interchangeable products. Any conversion is off-label clinical decision-making.

The comparative efficacy data: what the trials actually show

The best available evidence comes from comparing head-to-head trial results at maintenance doses. No direct randomized controlled trial has compared tirzepatide to semaglutide in the same patient population at the same time, but we can compare trial outcomes.

Trial	Drug	Dose	Population	Mean weight loss at 72 weeks	Patients achieving ≥15% weight loss
SURMOUNT-1	Tirzepatide	5 mg	Obesity without diabetes (N=630)	15.0%	50%
SURMOUNT-1	Tirzepatide	10 mg	Obesity without diabetes (N=636)	19.5%	62%
SURMOUNT-1	Tirzepatide	15 mg	Obesity without diabetes (N=630)	20.9%	63%
STEP 1	Semaglutide	2.4 mg	Obesity without diabetes (N=1,306)	14.9%	48%
STEP 1	Placebo	N/A	Obesity without diabetes (N=655)	2.4%	5%

From this data, Zepbound 10 mg produces weight loss comparable to Wegovy 2.4 mg (19.5% vs 14.9%). Zepbound 15 mg exceeds Wegovy 2.4 mg by about 6 percentage points.

For glycemic control in patients with type 2 diabetes:

Trial	Drug	Dose	Mean HbA1c reduction
SURPASS-2	Tirzepatide	10 mg	2.24%
SURPASS-2	Tirzepatide	15 mg	2.30%
SURPASS-2	Semaglutide	1.0 mg	1.86%
SUSTAIN-7	Semaglutide	1.0 mg	1.5%

Tirzepatide 10 mg outperforms semaglutide 1.0 mg for diabetes control. No published trial directly compares tirzepatide to semaglutide 2.4 mg for glycemic outcomes.

The pattern across trials: Zepbound 10 mg is roughly equivalent to Wegovy 2.4 mg for weight loss. Zepbound 15 mg exceeds Wegovy 2.4 mg.

The conversion framework providers use in practice

Providers do not convert doses directly. They restart titration at a lower dose of the new medication and escalate based on tolerance and response. The framework below reflects the most common clinical approach.

Converting from Zepbound to Wegovy:

Current Zepbound dose	Suggested Wegovy starting dose	Rationale
2.5 mg	0.25 mg	Start at standard Wegovy titration dose
5 mg	0.5 mg	One step above initiation dose
7.5 mg	1.0 mg	Mid-titration dose
10 mg	1.7 mg	One step below maintenance dose
12.5 mg or 15 mg	1.7 mg	One step below maintenance dose

Most providers start one to two titration steps below the Wegovy maintenance dose of 2.4 mg, then escalate weekly or every two weeks based on tolerance. Starting directly at 2.4 mg after switching from Zepbound carries high risk of nausea and vomiting because receptor sensitivity differs between the two drugs.

Converting from Wegovy to Zepbound:

Current Wegovy dose	Suggested Zepbound starting dose	Rationale
0.25 mg	2.5 mg	Standard Zepbound initiation dose
0.5 mg	2.5 mg	Standard Zepbound initiation dose
1.0 mg	5 mg	Second titration step
1.7 mg	7.5 mg	Third titration step
2.4 mg	7.5 mg or 10 mg	Start below expected equivalent dose

The pattern is the same: start below the expected equivalent dose and titrate up. Most patients switching from Wegovy 2.4 mg to Zepbound start at 7.5 mg and escalate to 10 mg or 12.5 mg based on response.

The retitration protocol for switching from Zepbound to Wegovy

The protocol below assumes you are switching due to insurance coverage changes, supply issues, or cost, not due to treatment failure. If Zepbound stopped working, switching to Wegovy is unlikely to restart weight loss without addressing underlying adherence, diet, or metabolic adaptation issues.

Week 1-4: Wegovy 0.5 mg or 1.0 mg weekly.

• If switching from Zepbound 2.5 to 5 mg, start at Wegovy 0.5 mg
• If switching from Zepbound 7.5 mg or higher, start at Wegovy 1.0 mg
• Take your last Zepbound dose, then start Wegovy 5 to 7 days later (one missed Zepbound dose)
• Monitor for nausea, which is common during the first two weeks as you adjust to the new medication

Week 5-8: Wegovy 1.7 mg weekly.

• Escalate if tolerating the starting dose without significant nausea or vomiting
• This is the dose where most patients report feeling comparable appetite suppression to their previous Zepbound dose
• If nausea is moderate to severe, stay at 1.0 mg for an additional 4 weeks

Week 9-12: Wegovy 2.4 mg weekly.

• The maintenance dose for most patients
• Expect weight loss to stabilize at a rate comparable to what you experienced on Zepbound within 8 to 12 weeks at this dose
• If you were losing 1 to 2 pounds per week on Zepbound 10 mg, expect similar results on Wegovy 2.4 mg after the adaptation period

Common mistake: Patients sometimes try to "bridge" the gap by taking a half dose of Zepbound while starting Wegovy. This increases side effects without improving outcomes. Pick one medication and commit to the titration schedule.

The retitration protocol for switching from Wegovy to Zepbound

Week 1-4: Zepbound 2.5 mg weekly.

• Standard starting dose regardless of your Wegovy dose
• Take your last Wegovy dose, then start Zepbound 7 days later
• The lower GLP-1 receptor occupancy during this transition may cause a temporary return of appetite, which resolves as you escalate

Week 5-8: Zepbound 5 mg weekly.

• Most patients switching from Wegovy 1.7 mg or 2.4 mg can escalate to 5 mg without significant side effects
• Appetite suppression at this dose is typically comparable to Wegovy 1.0 to 1.7 mg

Week 9-12: Zepbound 7.5 mg weekly.

• Intermediate dose between 5 mg and 10 mg
• Some patients stay here long-term if weight loss is satisfactory and side effects are minimal

Week 13-16: Zepbound 10 mg weekly.

• The dose most comparable to Wegovy 2.4 mg based on trial data
• Most patients switching from Wegovy reach this dose and maintain it
• Further escalation to 12.5 mg or 15 mg is optional and based on whether weight loss has plateaued

Week 17+: Optional escalation to 12.5 mg or 15 mg.

• Consider if weight loss stalls at 10 mg after 12+ weeks
• The incremental benefit from 10 mg to 15 mg is about 1.4 percentage points of additional weight loss in trial data (Jastreboff et al., NEJM 2022)

The advantage of switching from Wegovy to Zepbound is access to higher efficacy at the top end of the dose range. The disadvantage is a longer titration schedule (5 steps vs 4 steps).

What most articles get wrong about GLP-1 conversion

Most published content on this topic makes one of three errors:

Error 1: Claiming a fixed conversion ratio exists. Articles frequently state "Zepbound 5 mg equals Wegovy 1.0 mg" or similar. This is not supported by trial data. The dose-response curves are not parallel. Equivalence at one dose level does not predict equivalence at another. The statement conflates rough clinical approximation with pharmacological equivalence.

Error 2: Suggesting you can switch doses directly without retitration. Switching from Wegovy 2.4 mg to Zepbound 10 mg in a single step causes severe nausea in most patients. The receptor occupancy, half-life, and side effect profile differ enough that retitration is necessary. Direct switching is not standard of care.

Error 3: Ignoring the insurance and supply context. Most patients asking about conversion are not asking because one drug failed. They are asking because insurance stopped covering one and started covering the other, or because one is on backorder. The clinical question is "How do I switch without losing progress?" not "Which drug is better?" Most articles answer the wrong question.

The correct framing: conversion is a retitration process driven by external factors (cost, coverage, supply), not a pharmacological substitution.

When switching makes sense and when it doesn't

Switching makes sense when:

• Your insurance changes formulary coverage and one drug becomes unaffordable
• The brand-name drug you are taking is on FDA shortage and compounded alternatives are unavailable or undesirable
• You have reached the maximum dose of one medication and weight loss has stalled, and you want to try a higher-efficacy option (Wegovy 2.4 mg to Zepbound 12.5 or 15 mg)
• You are experiencing persistent side effects on one medication that may be receptor-specific (some patients tolerate tirzepatide better than semaglutide, or vice versa)

Switching does not make sense when:

• You are currently losing weight at a satisfactory rate on your current medication
• You are in the middle of a titration schedule and have not yet reached maintenance dose
• You are switching because you read that one drug is "better" without a specific clinical reason (both are effective; the difference in average outcomes is modest)
• You expect switching to restart weight loss that has plateaued due to metabolic adaptation (switching medications does not reset adaptation; addressing diet and activity does)

The decision to switch should be driven by a specific problem (cost, access, side effects, inadequate response at maximum dose), not by abstract comparison of trial results.

The insurance-driven conversion pattern we see most often

In our patient population, about 70% of conversion requests between Zepbound and Wegovy are driven by insurance formulary changes, not clinical factors. The typical pattern:

Pattern 1: Employer switches pharmacy benefit manager (PBM) mid-year. Patient has been stable on Wegovy 2.4 mg for 6+ months. New PBM covers Zepbound but not Wegovy, or requires a step-through of older GLP-1 medications first. Patient switches to compounded tirzepatide or brand Zepbound to avoid a coverage gap. Retitration takes 8 to 12 weeks to return to equivalent appetite suppression and weight-loss rate.

Pattern 2: Zepbound becomes available at lower cost through a different channel. Patient is paying out-of-pocket for Wegovy at $1,200 to $1,400 per month. Compounded tirzepatide becomes available at $300 to $500 per month. Patient switches to reduce cost. Weight loss continues at a comparable rate after retitration.

Pattern 3: Patient starts on compounded semaglutide, then switches to brand Zepbound when insurance begins covering it. This is the reverse of pattern 2. Retitration is required even though the patient is switching to a higher-efficacy drug, because the dose forms and pharmacokinetics differ.

The clinical takeaway: most conversions are logistical, not therapeutic. The goal is to maintain progress during the switch, not to optimize therapy (which was already working).

Side effects during the switch: what to expect

Switching from one GLP-1 medication to another resets the side effect adaptation curve. Even if you tolerated your previous medication well, expect some return of nausea, fatigue, and gastrointestinal symptoms during the first 2 to 4 weeks on the new drug.

Switching from Zepbound to Wegovy:

• Nausea is the most common side effect, reported by 40% to 50% of patients during the first month
• Typically peaks 24 to 48 hours after the first injection and improves by week 3 to 4
• Constipation is slightly more common on semaglutide than tirzepatide in head-to-head data (Frías et al., Lancet 2021)
• Injection site reactions are comparable between the two drugs

Switching from Wegovy to Zepbound:

• Diarrhea is slightly more common on tirzepatide than semaglutide, reported by 20% to 25% of patients during titration (Jastreboff et al., NEJM 2022)
• Nausea rates are similar to the Wegovy-to-Zepbound direction
• Fatigue during the first 2 weeks is common and resolves as the body adapts to the new receptor occupancy pattern

The adaptation window is 4 to 6 weeks. Most side effects resolve or become mild by week 6 at a stable dose. If side effects persist beyond 8 weeks, the issue is the medication itself, not the transition.

Managing side effects during the switch:

• Eat smaller, more frequent meals (5 to 6 per day instead of 3 large meals)
• Avoid high-fat foods, which worsen nausea on both medications
• Stay hydrated (64+ ounces of water per day)
• Take the injection in the evening if nausea is worse during the day, or in the morning if nausea is worse at night
• Use over-the-counter anti-nausea medication (ondansetron, meclizine) as needed during the first 2 to 3 weeks

The dose-response curves are not parallel

One reason direct conversion is impossible: the dose-response relationship for weight loss differs between tirzepatide and semaglutide.

For semaglutide, the curve is relatively linear between 0.5 mg and 2.4 mg. Each dose increase produces an incremental improvement in weight loss, with diminishing returns at the top end (Wilding et al., NEJM 2021).

For tirzepatide, the curve is steeper between 5 mg and 10 mg, then flattens between 10 mg and 15 mg. The jump from 5 mg to 10 mg produces a 4.5 percentage point increase in weight loss. The jump from 10 mg to 15 mg produces only a 1.4 percentage point increase (Jastreboff et al., NEJM 2022).

Practical implication: If you are switching from Wegovy 2.4 mg to Zepbound, the target dose is 10 mg, not 15 mg. The incremental benefit of 15 mg is small and comes with higher side effect rates. If you are switching from Zepbound 15 mg to Wegovy, there is no equivalent dose. Wegovy 2.4 mg is the maximum available dose and will produce less weight loss than Zepbound 15 mg in most patients.

Compounded tirzepatide to brand-name semaglutide conversions

Compounded tirzepatide and brand-name Zepbound contain the same active ingredient (tirzepatide) but differ in formulation, excipients, and sometimes concentration. The same is true for compounded semaglutide vs brand-name Wegovy.

Switching from compounded tirzepatide to brand Wegovy:

• Follow the same retitration protocol as Zepbound-to-Wegovy conversion
• Compounded tirzepatide doses are typically expressed in milligrams of active ingredient, which matches brand-name dosing
• If your compounded tirzepatide includes additional ingredients (B12, L-carnitine, etc.), those will not be present in Wegovy. Most patients do not notice a difference, but some report changes in energy or appetite during the first few weeks

Switching from compounded semaglutide to brand Zepbound:

• Follow the same retitration protocol as Wegovy-to-Zepbound conversion
• Compounded semaglutide is often dosed in milligrams (0.5 mg, 1.0 mg, 2.5 mg) rather than Wegovy's fixed pen doses (0.25, 0.5, 1.0, 1.7, 2.4 mg)
• If you were taking compounded semaglutide 2.5 mg weekly, that is slightly higher than Wegovy 2.4 mg. Start Zepbound at 7.5 mg and escalate to 10 mg.

Switching between two compounded products (tirzepatide to semaglutide or vice versa):

• The same retitration rules apply
• Compounded medications are not interchangeable with each other or with brand-name products
• Verify the concentration and dosing instructions with your pharmacy, as compounded products vary in formulation

Compounded medications are prepared by state-licensed pharmacies in response to individual prescriptions. They have not undergone FDA review and are not subject to the same manufacturing standards as brand-name drugs. Switching from compounded to brand-name (or vice versa) is a change in both active ingredient and formulation.

FAQ

Is there an official Zepbound to Wegovy conversion chart? No. The FDA has not published conversion guidance because tirzepatide and semaglutide are different molecules with different mechanisms. Providers use clinical judgment and trial data to guide retitration when switching.

What dose of Zepbound equals Wegovy 2.4 mg? Based on weight-loss outcomes in clinical trials, Zepbound 10 mg produces results comparable to Wegovy 2.4 mg. However, this is not a direct equivalence. Switching requires retitration, not a one-to-one dose swap.

Can I switch from Wegovy to Zepbound without restarting at a low dose? Not safely. Starting Zepbound at 10 mg after taking Wegovy 2.4 mg causes severe nausea in most patients. The standard protocol is to start at 2.5 mg and titrate up over 12 to 16 weeks.

How long does it take to switch from Zepbound to Wegovy? Most patients reach the Wegovy maintenance dose (2.4 mg) within 8 to 12 weeks of starting the switch. The exact timeline depends on your starting Zepbound dose and how quickly you tolerate dose escalations.

Will I gain weight while switching between medications? Most patients maintain their weight or continue losing at a slower rate during the retitration period. A small minority (10% to 15%) experience a 2 to 5 pound rebound during the first 4 weeks, which reverses once they reach an equivalent dose of the new medication.

Which is better for weight loss, Zepbound or Wegovy? Zepbound produces slightly greater weight loss on average. In clinical trials, Zepbound 15 mg resulted in 20.9% weight loss vs 14.9% for Wegovy 2.4 mg. The difference is meaningful but not dramatic. Both are effective.

Can I switch back and forth between Zepbound and Wegovy? Technically yes, but each switch requires retitration, which takes 8 to 12 weeks and resets the side effect adaptation curve. Frequent switching is not recommended unless driven by access or cost issues.

Do I need to stop one medication before starting the other? Yes. Take your last dose of the old medication, then start the new medication 5 to 7 days later (one missed dose). Do not overlap doses, as this increases the risk of severe nausea and hypoglycemia.

Will my insurance cover both medications? Most insurance plans cover one or the other, not both. Coverage is the most common reason patients switch. Check your formulary or contact your insurance provider to confirm which GLP-1 medications are covered under your plan.

Can I switch from Zepbound to Ozempic instead of Wegovy? Yes. Ozempic and Wegovy both contain semaglutide. The difference is the maximum dose: Ozempic goes up to 2.0 mg, Wegovy goes up to 2.4 mg. If switching for weight loss, Wegovy is the better choice because it reaches the higher dose shown to be effective in obesity trials.

What if I was taking compounded tirzepatide, not brand Zepbound? The same conversion principles apply. Compounded tirzepatide and brand Zepbound both contain tirzepatide. Follow the retitration protocol for switching to Wegovy based on your current compounded dose.

How do I know if the switch is working? You should feel comparable appetite suppression within 4 to 6 weeks of reaching an equivalent dose. Weight loss should resume at a similar rate within 8 to 12 weeks. If appetite returns and weight loss stalls after 12+ weeks on the new medication, contact your provider.

Sources

1. Jastreboff AM et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine. 2022.
2. Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2021.
3. Frías JP et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes. New England Journal of Medicine. 2021.
4. Davies M et al. Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes (SURPASS-2). Lancet. 2021.
5. Rosenstock J et al. Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1). Diabetes Care. 2021.
6. Ludvik B et al. Once-weekly tirzepatide versus once-daily insulin degludec as add-on to metformin with or without SGLT2 inhibitors in patients with type 2 diabetes (SURPASS-3). Lancet. 2021.
7. Del Prato S et al. Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4). Lancet. 2021.
8. Dahl D et al. Effect of Subcutaneous Tirzepatide vs Placebo Added to Titrated Insulin Glargine on Glycemic Control in Patients With Type 2 Diabetes (SURPASS-5). JAMA. 2022.
9. Garvey WT et al. Two-year effects of semaglutide in adults with overweight or obesity (STEP 5). Nature Medicine. 2022.
10. Rubino D et al. Effect of Continued Weekly Subcutaneous Semaglutide vs Placebo on Weight Loss Maintenance in Adults With Overweight or Obesity (STEP 4). JAMA. 2021.
11. Wadden TA et al. Effect of Subcutaneous Semaglutide vs Placebo as an Adjunct to Intensive Behavioral Therapy on Body Weight in Adults With Overweight or Obesity (STEP 3). JAMA. 2021.
12. American Diabetes Association. Standards of Medical Care in Diabetes - 2026. Diabetes Care. 2026.
13. Nauck MA et al. GLP-1 receptor agonists in the treatment of type 2 diabetes - state-of-the-art. Molecular Metabolism. 2021.
14. Müller TD et al. Glucagon-like peptide 1 (GLP-1). Molecular Metabolism. 2019.

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Platform Disclaimer. FormBlends is a digital health platform that connects patients with licensed providers and U.S.-based pharmacies. We do not manufacture, prescribe, or dispense medication directly. All clinical decisions are made by independent licensed providers.

Compounded Medication Notice. Compounded semaglutide and tirzepatide are not FDA-approved. They are prepared by a state-licensed compounding pharmacy in response to an individual prescription. Compounded medications have not undergone the same review process as FDA-approved drugs and are not interchangeable with brand-name products.

Results Disclaimer. Individual results vary. Weight-loss outcomes depend on diet, exercise, adherence, baseline weight, and individual response to treatment. Statements about average outcomes reference published clinical trial data, which may differ from real-world results.

Trademark Notice. Zepbound and Mounjaro are registered trademarks of Eli Lilly and Company. Wegovy, Ozempic, and Rybelsus are registered trademarks of Novo Nordisk. FormBlends is not affiliated with, endorsed by, or sponsored by Eli Lilly and Company or Novo Nordisk.