Zepbound vs Wegovy: Weight Loss Data, Side Effects, Cost, Compounded Equivalents

Key takeaways

Zepbound (tirzepatide) takes off more weight than Wegovy (semaglutide). In the only head-to-head trial, 751 adults with obesity lost 20.2% of their body weight on Zepbound's drug versus 13.7% on Wegovy's over 72 weeks, each at its maximum tolerated dose.
Wegovy has the broader label: proven cardiovascular risk reduction from the 17,604-person SELECT trial, liver disease (MASH with fibrosis), teenagers from age 12, a 7.2 mg dose and a daily pill. Zepbound's label adds moderate to severe obstructive sleep apnea.
The side effects are the same family, mostly nausea, diarrhea, vomiting and constipation during dose escalation. Label rates look different (nausea 44% on Wegovy, 25 to 29% on Zepbound), but in the head-to-head trial nausea affected 44% of both groups.
Cash prices in October 2026 are close: Wegovy $349 a month through Novo Nordisk's pharmacy, Zepbound $299 to $449 by dose through Lilly's. Since July 2026, eligible Medicare enrollees can get Wegovy, or Zepbound in the KwikPen (not vials or single-dose pens), for weight loss at a $50 copay through the temporary GLP-1 Bridge.
Compounded copies of either drug were never tested in a trial and, since the shortages ended, are legal only for a documented individual need. Neither drug has a generic.

Zepbound is tirzepatide, made by Eli Lilly: one peptide that activates two gut-hormone receptors, GIP and GLP-1. Wegovy is semaglutide, made by Novo Nordisk, which activates one, GLP-1. Zepbound removes more weight, by about six and a half percentage points head to head; which suits you depends on your heart, liver, sleep, age, coverage and whether you want a pill. This page compares the brand products as of October 2026. The molecules are compared in semaglutide vs tirzepatide: the real differences, the diabetes brands in tirzepatide vs Ozempic, and the compounded versions in our compounded semaglutide vs tirzepatide guide.

Zepbound vs Wegovy side by side

	Zepbound	Wegovy
Molecule and maker	Tirzepatide (Eli Lilly), a peptide built on the GIP sequence	Semaglutide (Novo Nordisk), a modified human GLP-1 (94% sequence match)
Mechanism	Activates the GIP and GLP-1 receptors	Activates the GLP-1 receptor only
Approved uses on the current label	Weight reduction and maintenance in adults with obesity, or overweight plus a weight-related condition; moderate to severe obstructive sleep apnea in adults with obesity	Weight reduction and maintenance in adults and children 12 and older; reducing heart attack, stroke and cardiovascular death in adults with established cardiovascular disease and obesity or overweight; noncirrhotic MASH with moderate to advanced fibrosis (accelerated approval)
Same drug for type 2 diabetes	Mounjaro	Ozempic (injection); Rybelsus (tablet)
Dose range	2.5 mg weekly to start; maintenance 5, 10 or 15 mg; 15 mg maximum	0.25 mg weekly to start; maintenance 2.4 mg (or 1.7 mg); up to 7.2 mg; tablet 1.5 mg daily climbing to 25 mg
How it comes	Single-dose pens; single-dose vials; multi-dose vials and KwikPens holding four doses	Single-dose pens and syringes; a FlexTouch pen holding four 2.4 mg doses; tablets; no vials
Head to head (SURMOUNT-5, 72 weeks)	20.2% weight loss at 10 or 15 mg	13.7% at 1.7 or 2.4 mg
Versus placebo	15.0%, 19.5% and 20.9% at 5, 10 and 15 mg versus 3.1% (72 weeks)	14.9% versus 2.4% at 2.4 mg (68 weeks); 18.7% versus 3.9% at 7.2 mg (72 weeks)
Cardiovascular outcome data	None in obesity yet; in type 2 diabetes, non-inferior to dulaglutide (SURPASS-CVOT), a Mounjaro indication, not a Zepbound one	SELECT: major cardiovascular events 6.5% versus 8.0% on placebo, a 20% relative reduction; on the label
Most common side effects (label, drug vs placebo)	Nausea 25 to 29% vs 8%; diarrhea 19 to 23% vs 8%; vomiting 8 to 13% vs 2%; injection-site reactions 6 to 8% vs 2%	Nausea 44% vs 16%; diarrhea 30% vs 16%; vomiting 24% vs 6%; constipation 24% vs 11%
Stopped because of side effects	4.8 to 6.7% vs 3.4%	6.8% vs 3.2%
Serious warnings	Boxed warning on thyroid C-cell tumors; pancreatitis, gallbladder disease, kidney injury from dehydration, low blood sugar with insulin or sulfonylureas, diabetic retinopathy, aspiration under anesthesia; weakens oral contraceptives	Same boxed warning and class warnings, plus heart-rate increase; stop two months before a planned pregnancy; altered skin sensation in 22% at 7.2 mg
Cash price, October 2026	$299 (2.5 mg), $399 (5 mg), $449 (7.5 to 15 mg) through Lilly's self-pay program; list about $1,086	Injection $349 through Novo Nordisk's pharmacy; tablet $149 to $299; list about $1,350
Medicare	Part D for sleep apnea; GLP-1 Bridge at $50 for the KwikPen only	Part D for cardiovascular risk reduction; GLP-1 Bridge at $50 for injection and tablets

Label facts are from the current prescribing information on DailyMed (Zepbound label) (Wegovy label); trial numbers are sourced below; prices are from our peptide therapy cost guide, collected October 9, 2026.

Weight loss: what the trials show

SURMOUNT-5, the head-to-head trial. 751 adults with obesity but no type 2 diabetes were randomized to the maximum tolerated weekly dose of tirzepatide (10 or 15 mg) or semaglutide (1.7 or 2.4 mg) for 72 weeks. Mean weight loss was 20.2% versus 13.7%, waist circumference fell 18.4 cm versus 13.0 cm, and more tirzepatide participants reached every threshold from 10% to 25% loss (Aronne 2025). It was open-label and Lilly-funded, neither of which plausibly explains a 6.5-point gap in measured weight.

The placebo-controlled trials. In STEP 1, 1,961 adults without diabetes lost 14.9% on semaglutide 2.4 mg versus 2.4% on placebo over 68 weeks, and half the semaglutide group lost at least 15% (Wilding 2021). In SURMOUNT-1, 2,539 similar adults lost 15.0%, 19.5% and 20.9% on tirzepatide 5, 10 and 15 mg versus 3.1% on placebo over 72 weeks, and 57% of the 15 mg group lost at least a fifth of their weight (Jastreboff 2022). Averages hide a wide spread: in both trials, between 9% and 15% of people on the drug lost less than 5%.

Wegovy's 7.2 mg dose. In STEP UP, 1,407 adults with obesity and no diabetes lost 18.7% on semaglutide 7.2 mg, 15.6% on 2.4 mg and 3.9% on placebo over 72 weeks. The higher dose had a price: gastrointestinal events in 70.8% versus 61.2% and 42.8%, and dysesthesia (burning, tingling or sensitive skin) in 22.9% versus 6.0% and 0.5% (Wharton 2025, STEP UP). No trial has compared 7.2 mg with tirzepatide; its 18.7% sits near SURMOUNT-1's 10 and 15 mg results, but cross-trial comparisons are the weakest kind.

Beyond the scale: heart, liver and sleep apnea

The heart. SELECT gave semaglutide 2.4 mg or placebo to 17,604 adults aged 45 or older with established cardiovascular disease and a BMI of 27 or more, without diabetes, for a mean of almost 40 months. Cardiovascular death, heart attack or stroke occurred in 6.5% versus 8.0%, a hazard ratio of 0.80 (Lincoff 2023). That result is a Wegovy indication, for the injection and the tablet. Tirzepatide's cardiovascular data come from type 2 diabetes: in SURPASS-CVOT, 13,299 patients with diabetes and atherosclerotic disease took tirzepatide or dulaglutide, an older GLP-1 drug proven to reduce events; the primary outcome occurred in 12.2% versus 13.1% (hazard ratio 0.92), non-inferior but not superior (Nicholls 2025). Since August 2026 that trial supports a cardiovascular indication on Mounjaro's label; Zepbound's label has none, and we found no published outcomes trial of tirzepatide in obesity without diabetes.

The liver. In ESSENCE, 800 adults with biopsy-proven MASH and stage 2 or 3 fibrosis took semaglutide 2.4 mg or placebo. At 72 weeks steatohepatitis resolved without worsening fibrosis in 62.9% versus 34.3%, and fibrosis improved without worsening steatohepatitis in 36.8% versus 22.4% (Sanyal 2025). The MASH indication is an accelerated approval on those biopsy results; the trial runs to 240 weeks, and continued approval depends on confirming a clinical benefit. Zepbound has no liver indication.

Sleep apnea. SURMOUNT-OSA ran two 52-week trials in 469 adults with obesity and moderate to severe obstructive sleep apnea. Tirzepatide at 10 or 15 mg cut the apnea-hypopnea index by 25.3 events an hour versus 5.3 on placebo in people not using positive airway pressure, and by 29.3 versus 5.5 in people who were (Malhotra 2024). Wegovy's label does not list sleep apnea.

Side effects: the labels versus the head-to-head trial

The label rates in the table above come from each drug's own pooled placebo trials, which differed in length, population (a quarter of the Zepbound pool and a fifth of the Wegovy pool had type 2 diabetes) and event collection, so the two columns cannot be compared directly (Wegovy label) (Zepbound label). The fair comparison is the one trial that gave both drugs to the same population. SURMOUNT-5's posted registry results, at maximum tolerated doses over 72 weeks (ClinicalTrials.gov SURMOUNT-5):

Adverse event in SURMOUNT-5	Tirzepatide (374 people)	Semaglutide (376 people)
Nausea	44%	44%
Diarrhea	24%	23%
Constipation	27%	28%
Vomiting	15%	21%
Burping	10%	8%
Injection-site reactions	9%	under 1%
Hair loss	8%	6%
Serious adverse events	4.8%	3.5%

Head to head, the stomach effects were nearly identical, vomiting was somewhat less common on tirzepatide, and injection-site reactions were a tirzepatide effect. Most gastrointestinal effects cluster after each dose increase; our GLP-1 side effects guide covers how long each lasts and what helps.

The serious warnings are shared because the drugs share a class, from the boxed warning on thyroid C-cell tumors in rodents to pancreatitis, gallbladder disease and aspiration under anesthesia. The practical differences: tirzepatide weakens oral contraceptives, so the Zepbound label advises a non-oral or added barrier method for four weeks after starting and after each dose increase; semaglutide's week-long half-life means stopping Wegovy at least two months before a planned pregnancy; and dysesthesia is mainly a 7.2 mg problem. The suicidal-ideation warning was removed from both labels in February 2026. More in is tirzepatide safe and does tirzepatide cause hair loss.

Doses and devices

Wegovy injection starts at 0.25 mg weekly and rises every four weeks through 0.5, 1 and 1.7 mg to 2.4 mg maintenance (1.7 mg is an accepted alternative), with the optional step to 7.2 mg. A missed dose is taken if the next one is more than two days away; after two or more missed doses the climb restarts lower. It comes in single-dose pens and syringes and a four-dose FlexTouch pen (Wegovy label).

Zepbound starts at 2.5 mg weekly for four weeks, then 5 mg, then 2.5 mg steps no sooner than every four weeks to a maintenance dose of 5, 10 or 15 mg (10 or 15 mg for sleep apnea); 2.5 mg is a starting dose only. A missed dose can be taken within four days. It comes in single-dose pens, single-dose vials, and four-dose multi-dose vials and KwikPens (Zepbound label). Full schedules: semaglutide dosage chart and tirzepatide dosage chart.

Cost, insurance and Medicare in October 2026

Cash. Wegovy injection costs $349 a month through Novo Nordisk's pharmacy, with $199 for the first two fills for new patients in 2026; the tablet costs $149 at the starting dose to $299 at maintenance. Zepbound vials or KwikPens cost $299 at 2.5 mg, $399 at 5 mg and $449 at 7.5 to 15 mg through Lilly's self-pay program when refilled within 45 days, $499 to $699 if late; TrumpRx lists Zepbound at an average of $346. List prices are about $1,350 (Wegovy) and $1,086 (Zepbound). On our arithmetic, thirteen four-week fills at maintenance cost about $4,540 for Wegovy ($4,240 with the new-patient offer) and about $5,640 for Zepbound at 10 mg ($299 + $399 + 11 × $449). Zepbound is cheaper at the starting doses, Wegovy at maintenance. Cash programs cannot be combined with insurance. Sources and HSA rules: the cost guide and tirzepatide cost guide.

Commercial insurance. Obesity coverage varies and usually needs prior authorization and a BMI threshold; Novo Nordisk says most covered Wegovy patients pay $25 or less with its savings card.

Medicare. Part D has long been barred from paying for weight-loss drugs, but it can cover one prescribed for another approved use: Wegovy to reduce cardiovascular risk, or Zepbound for sleep apnea in adults with obesity. Those go through the Part D plan (Reed Smith 2026). For weight loss alone, the temporary Medicare GLP-1 Bridge has run since July 1, 2026 through a CMS contractor. Per the insurer notice summarized in our tirzepatide cost guide, it covers Wegovy (injection and tablets), Foundayo and the Zepbound KwikPen, not Zepbound vials or single-dose pens, at a $50 copay, for a BMI of 35 or more; 30 or more with heart failure with preserved ejection fraction, uncontrolled hypertension or stage 3a or worse kidney disease; or 27 or more with prediabetes, a prior heart attack or stroke, or symptomatic peripheral artery disease.

Zepbound or Wegovy: who should choose which

Situation	Leans toward	Why
Largest possible weight loss	Zepbound	20.2% versus 13.7% head to head
Prior heart attack, stroke or peripheral artery disease	Wegovy	SELECT outcome data and a label indication, which also opens Part D coverage
Moderate to severe sleep apnea with obesity	Zepbound	Label indication, also Part D-coverable
MASH with stage 2 or 3 fibrosis	Wegovy	Label indication (accelerated approval)
Age 12 to 17	Wegovy	Zepbound is approved for adults only
Wants a pill	Wegovy tablet or Foundayo	Zepbound has no oral form
Did not tolerate one drug	Try the other, slowly	Tolerance differs between people; neither label offers a conversion, so the new drug usually starts low
Paying cash at maintenance	Wegovy, slightly	$349 versus $449 a month
Coverage for only one	The covered one	Both work; the plan sets the price more than the molecule does

Who should take neither: anyone with a personal or family history of medullary thyroid carcinoma or MEN 2, anyone pregnant, and anyone with severe gastroparesis, where both labels advise against use. A history of pancreatitis is not a listed contraindication but calls for a careful conversation. And neither suits a short course: in the withdrawal trials of both drugs, most of the lost weight returned within a year, as our compounded comparison details.

The pill options, in brief

Wegovy tablet. Semaglutide 25 mg daily after 30-day steps from 1.5, 4 and 9 mg, taken on an empty stomach with up to four ounces of water, 30 minutes before food or other medicines. In OASIS 4, 307 adults without diabetes lost 13.6% versus 2.2% on placebo at 64 weeks (Wharton 2025, OASIS 4). It shares Wegovy's cardiovascular indication.

Foundayo (orforglipron). Lilly's pill is not oral Zepbound. It is a small-molecule GLP-1 receptor agonist, neither a peptide nor a GIP agonist, approved in 2026 for weight management in adults. It is taken once daily with or without food, starting at 0.8 mg and rising in steps of at least 30 days to 5.5 mg and, if needed, 9, 14.5 or 17.2 mg; strong CYP3A4 inhibitors cap it at 9 mg (Foundayo label). In its 72-week trial in 3,127 adults without diabetes, the top dose produced 11.1% weight loss versus 2.1% on placebo, and adverse events led 5.3 to 10.3% of the orforglipron groups to stop (Wharton 2025, ATTAIN-1). Our October price survey does not cover it.

Compounded versions and their legal limits

Compounded tirzepatide and semaglutide are pharmacy-made versions of the same molecules, usually in vials dosed in syringe units. None was used in any trial on this page, and none is a generic; DailyMed lists no generic of either drug. Since the shortages ended (tirzepatide December 2024, semaglutide February 2025), a pharmacy may compound either only for a patient with a documented need the approved product cannot meet, and price is not such a need. FDA sent 55 warning letters to telehealth companies over compounded GLP-1 marketing in 2026 and proposed keeping both drugs off the 503B outsourcing list. Typical prices, $150 to $350 a month for semaglutide and $180 to $300 for tirzepatide, now undercut the brand cash programs by less than they did in 2024. The compounded semaglutide vs tirzepatide guide covers the products and risks; the legal tracker and is compounded tirzepatide legal cover the law.

Bottom line

On weight, Zepbound wins: about 20% average loss against about 14% for Wegovy 2.4 mg head to head, with nearly identical stomach side effects. On everything else, Wegovy's label is wider: proven cardiovascular protection in people with heart disease, a liver indication, approval for teenagers, a 7.2 mg dose and a daily pill. Zepbound's extra is sleep apnea. Cash prices sit within about $100 a month of each other, and coverage often decides. Choose on medical history first and price second, and plan to stay on it: the weight returns when the drug stops.

Frequently asked questions

+Is Zepbound better than Wegovy?

For weight loss alone, yes on the evidence. In SURMOUNT-5, the only head-to-head trial, 751 adults with obesity and no diabetes lost 20.2% of their body weight on the maximum tolerated dose of Zepbound's drug (tirzepatide) versus 13.7% on Wegovy's (semaglutide) over 72 weeks. Wegovy is the better-documented choice for someone with established heart disease, because its label carries a proven reduction in heart attacks, strokes and cardiovascular death; it also covers liver disease (MASH with fibrosis) and teenagers, and it comes as a pill.

+What is the difference between Zepbound and Wegovy?

The molecule and the label. Zepbound is tirzepatide from Eli Lilly, one peptide that activates both the GIP and GLP-1 receptors; Wegovy is semaglutide from Novo Nordisk, which activates the GLP-1 receptor only. Zepbound is approved for weight management and obstructive sleep apnea in adults; Wegovy for weight management from age 12, cardiovascular risk reduction and MASH with liver fibrosis. Both are weekly injections; Wegovy also has a daily tablet, and Zepbound also comes in vials.

+Which costs more, Zepbound or Wegovy?

Paying cash in October 2026, they are close. Zepbound costs $299 a month at 2.5 mg, $399 at 5 mg and $449 at 7.5 to 15 mg through Lilly's self-pay program with refills within 45 days. Wegovy injection costs $349 a month through Novo Nordisk's pharmacy, with $199 for the first two fills for new patients in 2026, and the Wegovy pill $149 to $299. At maintenance doses Wegovy is about $100 a month cheaper. List prices are about $1,086 (Zepbound) and $1,350 (Wegovy).

+Can you switch from Wegovy to Zepbound?

Yes, clinicians do it, but neither label has a conversion chart. The Zepbound label's only schedule starts at 2.5 mg weekly, and both labels say the drug should not be combined with another GLP-1 product, so the switch replaces one drug with the other. No randomized switching trial in people with obesity has been published; where a clinician starts after Wegovy is a judgment based on how you tolerated it and how long you have been off it.

+Can you switch from Zepbound to Wegovy?

Yes, and the same rules apply in reverse: no conversion table on either label, no combination with another GLP-1 drug, and the Wegovy escalation starts at 0.25 mg weekly and climbs every four weeks. Common reasons are insurance coverage, a cardiovascular indication or wanting the daily tablet. The Wegovy label itself only gives a switching rule between Wegovy injection 2.4 mg and Wegovy tablets 25 mg.

+Does Medicare cover Zepbound or Wegovy?

For some uses. Part D plans can cover Wegovy when it is prescribed to reduce cardiovascular risk and Zepbound when it is prescribed for obstructive sleep apnea in adults with obesity. For weight loss alone, the temporary Medicare GLP-1 Bridge, running since July 1, 2026, covers Wegovy injection and tablets, Foundayo and the Zepbound KwikPen (not vials or single-dose pens) at a $50 monthly copay for Part D enrollees who meet BMI criteria and get prior authorization.

+Which has fewer side effects, Zepbound or Wegovy?

Neither clearly. The labels list nausea in 44% of Wegovy patients versus 16% on placebo and 25 to 29% of Zepbound patients versus 8%, but those come from different trials, so the rows cannot be compared directly. In SURMOUNT-5, which gave both drugs to the same population, nausea affected 44% in each group, diarrhea and constipation were nearly identical, vomiting was less common on tirzepatide (15% versus 21%), and injection-site reactions were more common (9% versus under 1%). Altered skin sensation is a notable effect of the 7.2 mg Wegovy dose.

+Is there a pill version of Zepbound or Wegovy?

Wegovy has one: a daily semaglutide tablet that climbs from 1.5 mg to 25 mg over 90 days and produced 13.6% weight loss versus 2.2% on placebo at 64 weeks. Zepbound does not. Lilly's pill, Foundayo (orforglipron), is a different molecule: a small, non-peptide GLP-1 receptor agonist taken once daily with or without food, which produced 11.1% weight loss versus 2.1% at its top dose over 72 weeks.

+Is compounded tirzepatide the same as Zepbound?

It is meant to contain the same molecule, but it is not the same product. No compounded version of tirzepatide or semaglutide was used in any of the trials on this page, compounded products are not reviewed by FDA, and since the shortages ended (tirzepatide in December 2024, semaglutide in February 2025) a pharmacy may compound either only for a patient with a documented need the approved drug cannot meet. Neither drug has a generic version in the United States.