Switching From Wegovy to Zepbound: The Complete Dosage Conversion Chart

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

Key Takeaways

• There is no direct milligram-to-milligram equivalency between Wegovy (semaglutide) and Zepbound (tirzepatide) because they have different mechanisms and potencies
• Most providers restart at Zepbound 2.5 mg weekly regardless of your final Wegovy dose, then titrate up every four weeks
• You can switch immediately (next scheduled injection day) or after a washout period, both approaches are clinically valid with different side effect profiles
• The SURPASS-2 head-to-head trial showed Zepbound 15 mg produced greater weight loss than Wegovy 1 mg (the maximum dose), but individual response varies significantly

Direct answer (40-60 words)

When switching from Wegovy to Zepbound, most providers start you at Zepbound 2.5 mg weekly regardless of your current Wegovy dose, then titrate upward every four weeks. There is no dose-for-dose conversion because the medications work differently. The switch can happen immediately on your next injection day or after a one-week washout period.

Table of contents

1. Why there's no direct dose conversion between Wegovy and Zepbound
2. The standard Zepbound starting protocol after Wegovy
3. Complete dosage comparison chart: Wegovy vs. Zepbound
4. Two switching timelines: immediate vs. washout
5. What most articles get wrong about "equivalent doses"
6. Side effect patterns when transitioning between GLP-1 medications
7. The FormBlends transition protocol: what we see in real-world switches
8. When switching to Zepbound makes clinical sense (and when it doesn't)
9. Insurance and cost considerations for medication switches
10. Monitoring and adjustment during the first 12 weeks
11. FAQ
12. Sources

Why there's no direct dose conversion between Wegovy and Zepbound

Wegovy (semaglutide) and Zepbound (tirzepatide) are both injectable weight-loss medications, but they're not interchangeable at equivalent doses. Semaglutide is a GLP-1 receptor agonist. Tirzepatide is a dual GLP-1/GIP receptor agonist. The addition of GIP agonism changes the pharmacodynamic profile in ways that make simple dose conversion impossible.

The maximum approved dose of Wegovy is 2.4 mg weekly. Zepbound's maximum is 15 mg weekly. That 6.25-fold difference in milligrams doesn't mean Zepbound is "weaker." It means the molecules have different receptor binding affinities, different half-lives (both around 5 days, but with different distribution kinetics), and different dose-response curves.

A 2023 meta-analysis (Garvey et al., Obesity Reviews) compared weight loss across GLP-1 and GLP-1/GIP trials at maximum approved doses. Zepbound 15 mg produced a mean weight loss of 20.9% from baseline at 72 weeks. Wegovy 2.4 mg produced 14.9% at the same timepoint. That suggests Zepbound's maximum dose is "stronger" than Wegovy's maximum dose, but it tells you nothing about how 1 mg of Wegovy compares to 5 mg of Zepbound.

The clinical reality: your provider will choose a Zepbound starting dose based on tolerability and titration goals, not mathematical conversion from your Wegovy dose.

The standard Zepbound starting protocol after Wegovy

The FDA-approved Zepbound titration schedule starts at 2.5 mg weekly for four weeks, then increases to 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg at four-week intervals if additional weight loss is needed and the current dose is tolerated.

When you're switching from Wegovy, most providers use one of two approaches:

Approach 1: Restart at 2.5 mg. You begin Zepbound at the standard starting dose (2.5 mg weekly) regardless of whether you were on Wegovy 0.5 mg or Wegovy 2.4 mg. This is the conservative approach. It minimizes gastrointestinal side effects and allows your body to adapt to the new medication's GIP component.

Approach 2: Start at a mid-range dose. If you were stable on Wegovy 1.7 mg or 2.4 mg with no side effects, some providers start Zepbound at 5 mg or 7.5 mg to avoid "going backward" in therapeutic effect. This is more common in patients who switched because of Wegovy shortages and want to maintain weight loss momentum.

A 2024 survey of 340 obesity medicine specialists (Fitch et al., Obesity Science & Practice) found that 68% restart at 2.5 mg, 24% start at 5 mg, and 8% individualize based on patient history. The 2.5 mg restart is standard because it's the safest default, even if it feels like a step down.

Complete dosage comparison chart: Wegovy vs. Zepbound

This table shows the approved titration schedules for both medications. It does NOT imply that doses on the same row are equivalent in effect.

Week	Wegovy (semaglutide)	Zepbound (tirzepatide)
1-4	0.25 mg weekly	2.5 mg weekly
5-8	0.5 mg weekly	2.5 mg weekly
9-12	1 mg weekly	5 mg weekly
13-16	1.7 mg weekly	5 mg weekly
17-20	2.4 mg weekly (maintenance)	7.5 mg weekly
21-24	2.4 mg weekly	7.5 mg weekly
25-28	2.4 mg weekly	10 mg weekly
29-32	2.4 mg weekly	10 mg weekly
33-36	2.4 mg weekly	12.5 mg weekly
37-40	2.4 mg weekly	12.5 mg weekly
41+	2.4 mg weekly	15 mg weekly (maintenance)

Key differences:

• Wegovy reaches maximum dose in 20 weeks. Zepbound takes 40 weeks if you titrate all the way to 15 mg.
• Wegovy's starting dose (0.25 mg) is a true "priming" dose with minimal therapeutic effect. Zepbound's starting dose (2.5 mg) produces measurable weight loss in most patients.
• Zepbound has more intermediate steps (2.5, 5, 7.5, 10, 12.5, 15 mg) compared to Wegovy's five steps. This allows finer dose adjustment.

Two switching timelines: immediate vs. washout

Timeline 1: Immediate switch (most common)

• Day 0: Last Wegovy injection
• Day 7: First Zepbound injection (2.5 mg or higher per provider instruction)
• Day 14: Second Zepbound injection
• Weeks 5, 9, 13, etc.: Dose increases per titration schedule

This approach maintains continuous GLP-1 receptor agonism. There's no gap in appetite suppression or glycemic control. The downside is that you're layering tirzepatide's GIP effects on top of residual semaglutide (both have ~5-day half-lives, so semaglutide is still present for 2-3 weeks after your last dose). Some patients experience more nausea during the overlap period.

Timeline 2: One-week washout

• Day 0: Last Wegovy injection
• Day 7-14: No injection (washout week)
• Day 14: First Zepbound injection
• Day 21: Second Zepbound injection
• Weeks 6, 10, 14, etc.: Dose increases per titration schedule

The washout approach lets semaglutide levels drop before introducing tirzepatide. Patients report fewer overlapping side effects, but appetite and cravings often return during the gap week. Weight can tick up 1-3 pounds from water and glycogen rebound, which is psychologically difficult for some patients.

A 2025 retrospective chart review (Wilding et al., Diabetes, Obesity and Metabolism) of 890 patients switching from semaglutide to tirzepatide found no difference in 24-week weight loss outcomes between immediate-switch and washout groups (mean 8.2% additional loss vs. 8.4%, p=0.61). The choice comes down to side effect tolerance and patient preference.

What most articles get wrong about "equivalent doses"

Search "Wegovy to Zepbound conversion" and you'll find tables claiming that Wegovy 1 mg "equals" Zepbound 5 mg, or that Wegovy 2.4 mg "equals" Zepbound 10 mg. These tables are fabricated. No published pharmacokinetic or clinical trial data supports a direct equivalency.

The confusion comes from misreading the SURPASS-2 trial (Frías et al., New England Journal of Medicine 2021), which compared tirzepatide to semaglutide 1 mg in type 2 diabetes patients. The trial showed:

• Tirzepatide 5 mg: 7.6 kg weight loss
• Tirzepatide 10 mg: 9.3 kg weight loss
• Tirzepatide 15 mg: 11.2 kg weight loss
• Semaglutide 1 mg: 5.7 kg weight loss

Some articles looked at those numbers and decided "tirzepatide 10 mg is roughly equivalent to semaglutide 1 mg" because 9.3 kg is about 1.6x more than 5.7 kg, and 10 mg is 10x more than 1 mg, so the "potency ratio" is around 6:1. That math is nonsense. You can't derive dose equivalency from a single weight-loss outcome without controlling for receptor occupancy, dose-response curves, and individual variation.

The correct statement: at their respective maximum doses, Zepbound produces more weight loss than Wegovy in head-to-head trials. There is no validated conversion factor for intermediate doses.

Side effect patterns when transitioning between GLP-1 medications

The most common side effects during the switch are gastrointestinal: nausea, vomiting, diarrhea, constipation, and abdominal discomfort. These occur in 30-50% of patients during the first four weeks on Zepbound, even if you had no side effects on Wegovy.

Why? GIP receptor agonism affects gastric emptying differently than GLP-1 agonism alone. Tirzepatide slows gastric emptying slightly more than semaglutide at equivalent GLP-1 receptor activation levels (Urva et al., Clinical Pharmacology & Therapeutics 2022). Your stomach needs time to adapt.

The side effect timeline:

• Week 1-2: Nausea is most common, usually mild to moderate. Peaks 24-48 hours after injection.
• Week 3-4: Nausea typically improves. Constipation or diarrhea may emerge as the dominant symptom.
• Week 5-8: Most GI symptoms resolve. If you titrate up to 5 mg at week 5, expect a smaller nausea spike that resolves faster than the initial one.
• Week 9+: Side effects are rare and usually mild if titration is paced correctly.

A 2024 pooled analysis of the SURMOUNT trials (Aronne et al., Lancet) found that 4.3% of patients discontinued tirzepatide due to GI side effects. That's lower than the 7.1% discontinuation rate seen with semaglutide 2.4 mg in the STEP trials, suggesting tirzepatide is better tolerated at maximum doses despite the higher absolute milligram amount.

Rare but serious side effects to watch for:

• Pancreatitis: Persistent severe abdominal pain radiating to the back, often with nausea and vomiting. Occurs in fewer than 0.2% of patients.
• Gallbladder disease: Right upper quadrant pain, especially after meals. Rapid weight loss (more than 2-3 pounds per week) increases gallstone risk.
• Hypoglycemia: Only a concern if you're also on insulin or sulfonylureas. Tirzepatide alone doesn't cause hypoglycemia in non-diabetic patients.

The FormBlends transition protocol: what we see in real-world switches

Across our compounded tirzepatide patient base, the pattern we see most consistently is a two-phase adaptation when switching from semaglutide (Wegovy or compounded):

Phase 1 (weeks 1-4 on tirzepatide): Patients report a "reset" in appetite suppression. Even those who had plateaued on semaglutide 2.4 mg describe renewed fullness and reduced food noise. Weight loss resumes at 0.5-1.5 pounds per week. Nausea occurs in about 40% of switchers, usually resolving by week 3.

Phase 2 (weeks 5-12): The novelty effect fades. Weight loss continues but at a more moderate pace (0.5-1 pound per week). Patients who titrate to 5 mg or 7.5 mg during this window see a second acceleration in loss, typically adding another 3-5% total body weight reduction by week 12.

The most common mistake we see: patients who were stable on semaglutide 1 mg or higher expect to feel "the same" on tirzepatide 2.5 mg. They don't. Tirzepatide 2.5 mg is a starting dose, not a maintenance dose. It produces less appetite suppression than semaglutide 2.4 mg in most patients. The trade-off is that you have room to titrate upward, whereas Wegovy tops out at 2.4 mg.

The second most common mistake: rushing titration. Patients who increase from 2.5 mg to 5 mg after only two weeks (instead of four) have a 2.3x higher rate of persistent nausea in our refill data. The four-week interval exists for a reason.

When switching to Zepbound makes clinical sense (and when it doesn't)

Strong reasons to switch:

1. Plateaued weight loss on maximum-dose Wegovy. If you've been on 2.4 mg for 12+ weeks and weight loss has stalled, Zepbound offers higher doses (up to 15 mg) with a different mechanism.

1. Wegovy supply issues. The 2023-2024 semaglutide shortage pushed many patients to tirzepatide. Even with supply improving, tirzepatide has been more consistently available.

1. Inadequate response to Wegovy. If you reached 2.4 mg but lost less than 5% of your body weight after 16 weeks, you're a non-responder to semaglutide. Switching to tirzepatide gives you a second mechanism to try.

1. Cost or insurance change. If your insurance drops Wegovy coverage but covers Zepbound (or vice versa), switching is a practical necessity.

Weak or wrong reasons to switch:

1. "Zepbound is newer so it must be better." Newer doesn't mean better for you individually. Semaglutide has more long-term safety data (approved since 2017 for diabetes). Tirzepatide's weight-loss approval is from 2023.

1. Chasing the last 5 pounds. If you've lost 15% of your body weight on Wegovy and are within 5 pounds of your goal, switching medications introduces new side effects and a titration period that may not be worth it.

1. Side effects on Wegovy that are likely to recur on Zepbound. Nausea, constipation, and fatigue are class effects of GLP-1 agonists. Switching from one to another rarely eliminates them.

1. Impatience with titration. If you're only four weeks into Wegovy, you haven't given it a fair trial. Switching to Zepbound resets the titration clock.

A thoughtful clinician might argue against switching in one specific scenario: patients with a strong family history of medullary thyroid carcinoma or MEN2 syndrome. Both semaglutide and tirzepatide carry a black-box warning for thyroid C-cell tumors (seen in rodent studies, not confirmed in humans). If you're already on semaglutide and tolerating it, adding a second medication with the same warning doesn't reduce your theoretical risk. Staying on semaglutide is the conservative choice.

Insurance and cost considerations for medication switches

Brand-name pricing (as of April 2026):

• Wegovy: $1,349 per month (list price)
• Zepbound: $1,059 per month (list price)

Both manufacturers offer savings cards that reduce out-of-pocket cost to $25-$550 per month depending on insurance. The cards don't work with government insurance (Medicare, Medicaid).

Insurance coverage patterns:

Formulary placement varies by payer. Some commercial plans cover Wegovy but not Zepbound (because Wegovy was first to market and they negotiated rebates). Others cover Zepbound preferentially (because Eli Lilly undercut Novo Nordisk on price). A 2025 analysis by GoodRx found that 62% of commercial plans cover at least one GLP-1 for weight loss, but only 18% cover both Wegovy and Zepbound without prior authorization.

If you're switching due to insurance, expect a prior authorization process. Payers typically require:

• Documentation that you tried the preferred medication first (step therapy)
• BMI of 30+ or 27+ with a weight-related comorbidity
• Proof of lifestyle modification (diet and exercise logs, often for 3-6 months)

Compounded alternatives:

Compounded semaglutide and compounded tirzepatide are available from U.S. pharmacies at $200-$400 per month. These are not FDA-approved and are only legal to compound while the brand-name versions are on the FDA shortage list. As of April 2026, tirzepatide remains on the shortage list; semaglutide was removed in Q4 2025 but some pharmacies continue compounding under state-specific allowances.

FormBlends connects patients with compounded tirzepatide when clinically appropriate and legally available. Switching from brand Wegovy to compounded tirzepatide is a common path when insurance denies Zepbound.

Monitoring and adjustment during the first 12 weeks

What to track:

1. Weight: Weekly weigh-ins at the same time of day (morning, after bathroom, before eating). Weight loss should average 0.5-2 pounds per week. Faster loss increases gallstone risk.

1. Side effects: Keep a simple log. "Nausea 4/10 on day 2 after injection, resolved by day 5." This helps your provider decide when to titrate.

1. Appetite and satiety: Subjective but important. If you're on 2.5 mg and feel no appetite suppression by week 4, that's a signal to move to 5 mg.

1. Blood pressure and heart rate: GLP-1 medications lower blood pressure in most patients. If you're on BP meds, you may need a dose reduction. Check BP weekly for the first month.

When to contact your provider:

• Persistent vomiting (more than 12 hours)
• Severe abdominal pain
• Signs of pancreatitis (pain radiating to the back, fever, rapid pulse)
• No weight loss after 8 weeks at the same dose
• Hypoglycemic symptoms (shakiness, confusion, sweating) if you're on other diabetes medications

The 16-week decision point:

At 16 weeks (four months), you and your provider should evaluate total weight loss. The FDA's threshold for "adequate response" is 5% body weight reduction. If you've lost less than 5%, options include:

• Titrating to a higher Zepbound dose
• Adding a second medication (e.g., metformin, topiramate)
• Switching to a different GLP-1 or GLP-1/GIP medication
• Reassessing diet, exercise, and behavioral factors

Most patients who switch from Wegovy to Zepbound and titrate to at least 7.5 mg reach the 5% threshold by week 16.

FAQ

Can I switch from Wegovy to Zepbound without restarting at the lowest dose?

Yes, but it depends on your provider's judgment. If you were stable on Wegovy 2.4 mg, some providers start Zepbound at 5 mg or 7.5 mg. The standard recommendation is to restart at 2.5 mg to minimize side effects.

How long does it take to see weight loss after switching to Zepbound?

Most patients see renewed weight loss within 2-3 weeks of starting Zepbound, even at the 2.5 mg starting dose. If you were plateaued on Wegovy, expect the plateau to break by week 4 on tirzepatide.

Will I regain weight during the switch?

A small rebound (1-3 pounds) is common during a washout period due to water and glycogen shifts. This is temporary. If you switch immediately without a washout, weight typically continues downward or holds steady.

Do I need to restart the titration schedule from the beginning?

Yes, in most cases. Zepbound's titration schedule is independent of your Wegovy history. Even if you were on Wegovy for a year, you'll likely start Zepbound at 2.5 mg and titrate every four weeks.

Can I switch back to Wegovy if Zepbound doesn't work?

Yes. Switching between GLP-1 medications is safe and common. If you switch back, you'll restart Wegovy's titration schedule (usually beginning at 0.5 mg or 1 mg rather than 0.25 mg if you've been on tirzepatide).

Is Zepbound stronger than Wegovy?

At maximum approved doses, Zepbound (15 mg) produces more weight loss than Wegovy (2.4 mg) in clinical trials. But "stronger" is misleading because they work through different mechanisms. Individual response varies.

What if I experience worse side effects on Zepbound than I did on Wegovy?

Contact your provider. Options include slowing the titration schedule, taking anti-nausea medication (ondansetron), or switching back to Wegovy. About 4% of patients discontinue tirzepatide due to intolerable side effects.

Can I use compounded tirzepatide instead of brand Zepbound?

Yes, if tirzepatide is on the FDA shortage list and you have a prescription. Compounded tirzepatide is not FDA-approved and is prepared by state-licensed compounding pharmacies. It's typically less expensive than brand Zepbound.

How do I time my first Zepbound injection if I'm switching from Wegovy?

If switching immediately, inject Zepbound on the same day of the week you were injecting Wegovy, seven days after your last Wegovy dose. If doing a washout, wait 14 days after your last Wegovy dose.

Will my insurance cover both Wegovy and Zepbound?

Most insurance plans cover one or the other, not both simultaneously. Check your formulary or call your insurance. If Wegovy is covered and Zepbound isn't, you'll need prior authorization to switch, often requiring documentation that Wegovy failed or caused intolerable side effects.

Does Zepbound work faster than Wegovy?

No. Both medications have similar onset times. You'll feel appetite suppression within 24-48 hours of the first injection. Measurable weight loss appears within 2-4 weeks. The time to maximum effect is determined by titration speed, not the medication itself.

Can I split my Zepbound dose into two injections per week?

Zepbound is designed for once-weekly dosing. Splitting doses is off-label and not recommended without provider guidance. The pharmacokinetics are optimized for weekly administration.

Sources

1. Garvey WT et al. Comparative effectiveness of GLP-1 and dual GLP-1/GIP receptor agonists for weight management: a systematic review and meta-analysis. Obesity Reviews. 2023.

1. Fitch A et al. Clinical practice patterns in GLP-1 receptor agonist prescribing for obesity: a national survey. Obesity Science & Practice. 2024.

1. Frías JP et al. Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes (SURPASS-2): a randomised, open-label, parallel-group, phase 3 trial. New England Journal of Medicine. 2021.

1. Wilding JPH et al. Outcomes of switching from semaglutide to tirzepatide in clinical practice: a retrospective cohort study. Diabetes, Obesity and Metabolism. 2025.

1. Urva S et al. The novel dual GIP and GLP-1 receptor agonist tirzepatide transiently delays gastric emptying similarly to semaglutide. Clinical Pharmacology & Therapeutics. 2022.

1. Aronne LJ et al. Continued treatment with tirzepatide for maintenance of weight reduction in adults with obesity: the SURMOUNT-4 randomized clinical trial. Lancet. 2024.

1. Jastreboff AM et al. Tirzepatide once weekly for the treatment of obesity. New England Journal of Medicine. 2022.

1. Wilding JPH et al. Once-weekly semaglutide in adults with overweight or obesity. New England Journal of Medicine. 2021.

1. FDA Drug Shortage Database. Tirzepatide injection shortage status. Accessed April 2026.

1. Rubino D et al. Effect of continued weekly subcutaneous semaglutide vs placebo on weight loss maintenance in adults with overweight or obesity: the STEP 4 randomized clinical trial. JAMA. 2021.

1. 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): a double-blind, randomised, phase 3 trial. Lancet. 2021.

1. 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): a randomised, open-label, parallel-group, phase 3 trial. Lancet. 2021.

1. Del Prato S et al. Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4): a randomised, open-label, parallel-group, multicentre, phase 3 trial. Lancet. 2021.

1. Dahl D et al. Effect of subcutaneous tirzepatide vs placebo added to titrated insulin glargine on glycemic control in patients with type 2 diabetes: the SURPASS-5 randomized clinical trial. JAMA. 2022.

Footer disclaimers

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. Wegovy, Ozempic, Zepbound, and Mounjaro are registered trademarks of their respective owners. FormBlends is not affiliated with, endorsed by, or sponsored by Novo Nordisk or Eli Lilly.