Tirzepatide compared
Mounjaro vs Zepbound: one medicine, two names
Mounjaro vs Zepbound is an unusual comparison: it is one medicine under two brand names. Both are tirzepatide from Eli Lilly, injected once a week. What changes is the approved use, the name used where you live, some label wording and, often, what insurance covers. Here is each difference, with the label it comes from.
On this page
- Is Zepbound the same as Mounjaro?
- Mounjaro vs Zepbound at a glance
- What each brand is approved for in the US
- How one medicine came to have two names
- Mounjaro vs Zepbound in the UK and EU
- How tirzepatide works, in either brand
- Mounjaro vs Zepbound for weight loss: what the labels report
- Mounjaro vs Zepbound side effects
- Doses, devices and label wording
- Cost and coverage: why the brand name matters
- Switching between Mounjaro and Zepbound
- Questions to bring to your prescriber
- Questions people ask
- Sources
In short
- Mounjaro and Zepbound are the same medicine: tirzepatide from Eli Lilly, a once-weekly injection in the same six strengths, from 2.5 mg to 15 mg, and the same kinds of pen and vial.1,2
- In the US, Mounjaro is approved for type 2 diabetes and to lower cardiovascular risk in adults with type 2 diabetes at high risk; Zepbound is approved for weight reduction and long-term maintenance, and for moderate to severe obstructive sleep apnea in adults with obesity.1,2
- The Zepbound name is not used in the UK or EU, where Mounjaro itself is licensed for both type 2 diabetes and weight management.3,4
- Their labels report different trials, so their numbers differ: in Zepbound's 72-week SURMOUNT-1 trial in adults without diabetes, average weight loss was 15.0% to 20.9% across the 5 to 15 mg doses, against 3.1% on placebo, counting everyone randomized.2
- Which brand you are prescribed, and whether your plan covers it, usually depends on why it is prescribed. That is your prescriber's call, and Handle records either one the same way.
Is Zepbound the same as Mounjaro?
Yes, where it counts: both contain tirzepatide. The differences are about approval, labeling and coverage.
The same in both
- The active ingredient, tirzepatide, and the maker, Eli Lilly1,2
- One injection under the skin a week, at any time of day, with or without meals1,2
- Six strengths, 2.5 mg to 15 mg, in the same kinds of pen and vial1,2
- The boxed warning, the other warnings and the reasons not to use it1,2
- Fridge storage, with a limited time allowed at room temperature1,2
Different between them
Mounjaro vs Zepbound at a glance
Label facts, side by side. None of this is a dose to take: your prescriber sets that. For every GLP-1 medicine in one place, see GLP-1 medications compared.
| Mounjaro | Zepbound | |
|---|---|---|
| Made by | Eli Lilly and Company | Eli Lilly and Company |
| Active ingredient | Tirzepatide, a GIP and GLP-1 receptor agonist1 | Tirzepatide, a GIP and GLP-1 receptor agonist2 |
| First US approval | May 13, 20229 | November 8, 20237 |
| Approved in the US for | Type 2 diabetes in adults and children 10 and older; lowering cardiovascular risk in adults with type 2 diabetes at high risk1 | Weight reduction and long-term maintenance in adults with obesity, or overweight plus a weight-related condition; moderate to severe obstructive sleep apnea in adults with obesity2 |
| How it's taken | Injection under the skin, once a week1 | Injection under the skin, once a week2 |
| Strengths | 2.5, 5, 7.5, 10, 12.5 and 15 mg1 | 2.5, 5, 7.5, 10, 12.5 and 15 mg2 |
| Forms in the US | Single-dose pen or vial; four-dose vial; four-dose KwikPen1 | The same four forms2 |
| Half-life | About 5 days1 | About 5 to 6 days in people with overweight or obesity2 |
| Storage | Fridge, 2–8 °C (36–46 °F); a single-dose pen or vial may be kept up to 30 °C (86 °F) for a total of 21 days1 | The same2 |
| Nausea in the main label trials | 12–18% vs 4% on placebo (type 2 diabetes)1 | 25–29% vs 8% on placebo (weight management)2 |
| Boxed warning | Risk of thyroid C-cell tumors1 | The same2 |
| UK and EU | Licensed for type 2 diabetes and weight management3,4 | Name not used there3,4 |
What these half-life figures mean is explained in our Mounjaro half-life guide, which covers Zepbound too.
What each brand is approved for in the US
Mounjaro's two uses are improving blood sugar control in adults and children 10 and older with type 2 diabetes (the children's use was added in December 2025), and reducing the risk of cardiovascular death, non-fatal heart attack or non-fatal stroke in adults with type 2 diabetes at high risk (added in August 2026).1,9 Zepbound's are reducing excess body weight and keeping it off long term in adults with obesity, or overweight plus a weight-related condition, and treating moderate to severe obstructive sleep apnea in adults with obesity.2 The two can overlap: someone with type 2 diabetes and obesity may fit both labels, and Zepbound's own trials included adults with type 2 diabetes.2 Which brand is prescribed is a clinical decision and, often, an insurance one.
How one medicine came to have two names
Tirzepatide's approvals and label changes, in order.
- May 2022Mounjaro approved in the US
Tirzepatide's first approval, for adults with type 2 diabetes.9
- Nov 2023
- Dec 2024Zepbound for sleep apnea
The FDA called it the first drug treatment option for certain patients with obstructive sleep apnea.8
- Jan 2026
- Feb 2026A warning removed from Zepbound
After an FDA review found no increased risk of suicidal behavior or ideation with GLP-1 medicines, that warning came off Zepbound's label. Mounjaro was not among the products named because, like other diabetes labels, its label did not carry the warning. The FDA still advises telling your clinician about new or worsening depression, suicidal thoughts or any unusual changes in mood or behavior; in the US, you can call or text 988 for support.2,12
- Aug 2026A major Mounjaro label update
A cardiovascular indication, and new wording about the 2.5 mg starting dose (see below).1
Mounjaro vs Zepbound in the UK and EU
There is no Zepbound in the UK or EU. There, tirzepatide for weight management is sold as Mounjaro, and the same product carries both licenses: the MHRA authorized the weight-management use in November 2023 and a four-dose Mounjaro KwikPen in January 2024.3,4,5 In the EU, the weight-management use covers adults with a BMI of 30 or more, or 27 to under 30 with a weight-related health problem.4
On the NHS in England, NICE recommends tirzepatide for weight management only for people with a BMI of at least 35 and at least one weight-related condition (lower for some ethnic backgrounds), and NHS England is rolling it out in phases, starting with people who have the highest BMI and several conditions.6 Elsewhere, including Canada and Australia, check the brand name on your prescription with your pharmacist. UK readers comparing tirzepatide with semaglutide can see Mounjaro vs Wegovy.
How tirzepatide works, in either brand
Tirzepatide is one molecule that activates two gut-hormone receptors, GIP and GLP-1.2 That sets it apart from GLP-1-only medicines such as semaglutide. GLP-1 helps regulate appetite and how much we eat. Zepbound's label says nonclinical studies suggest GIP "may further contribute" to that, which is laboratory evidence rather than proof of an extra effect in people.2
Tirzepatide also helps the body release insulin when blood sugar is high, lowers glucagon, and slows stomach emptying, most of all after the first dose.1,2 A fatty-acid chain that binds to albumin in the blood makes it long-acting enough for one injection a week.1 None of this depends on the name on the box.
Mounjaro vs Zepbound for weight loss: what the labels report
Mounjaro's trials were built around blood sugar, so its label reports weight change in kilograms. Zepbound's were built around weight, so its label reports percentages.
| Trial | Who took part | Length | Average weight change |
|---|---|---|---|
| SURMOUNT-1 (Zepbound label) | Adults with obesity, or overweight plus a weight-related condition, without diabetes | 72 weeks | −15.0% on 5 mg, −19.5% on 10 mg, −20.9% on 15 mg; placebo −3.1%2,10 |
| SURMOUNT-2 (Zepbound label) | Adults with obesity or overweight and type 2 diabetes | 72 weeks | −12.8% on 10 mg, −14.7% on 15 mg; placebo −3.2%2 |
| SURPASS-1 (Mounjaro label) | Adults with type 2 diabetes managed with diet and exercise alone | 40 weeks | −6.3 kg on 5 mg, −7.0 kg on 10 mg, −7.8 kg on 15 mg; placebo −1.0 kg1 |
The SURMOUNT figures count everyone who was randomly assigned, whether or not they kept taking the medicine (a treatment-regimen estimate). The SURPASS-1 figures are as printed in Mounjaro's label, from a modified intention-to-treat analysis. All are averages from trials, not a prediction for any one person.
Why the numbers differ when the medicine doesn't
These trials differ in who took part (with or without type 2 diabetes), how long they ran (40 or 72 weeks) and what they were built to measure (blood sugar or weight), and any of those can move an average. So the figures cannot be set against each other as if they came from one trial, and they cannot show that one brand works better: a trial of Mounjaro against Zepbound would be a trial of tirzepatide against itself.
For tirzepatide against a different medicine, including the head-to-head SURMOUNT-5 trial, see semaglutide vs tirzepatide.
Mounjaro vs Zepbound side effects
Both labels list the same kinds of side effects, mostly in the stomach and gut, but their tables come from different trials. Each figure is the range across the 5, 10 and 15 mg groups, with the placebo rate alongside.
| Side effect | Mounjaro label (type 2 diabetes trials) | Zepbound label (72-week weight trials) |
|---|---|---|
| Nausea | 12–18% (placebo 4%) | 25–29% (placebo 8%) |
| Diarrhea | 12–17% (placebo 9%) | 19–23% (placebo 8%) |
| Vomiting | 5–9% (placebo 2%) | 8–13% (placebo 2%) |
| Constipation | 6–7% (placebo 1%) | 11–17% (placebo 5%) |
| Indigestion | 5–8% (placebo 3%) | 9–10% (placebo 4%) |
| Stomach pain | 5–6% (placebo 4%) | 9–10% (placebo 5%) |
| Injection-site reactions | 3.2% across all doses (placebo 0.4%) | 6–8% (placebo 2%) |
| Hair loss | Reported after approval; no trial rate given | 4–5% (placebo 1%) |
| Stopped because of stomach side effects | 3.0–6.6% (placebo 0.4%) | 1.9–4.3% (placebo 0.5%) |
Sources: Mounjaro label, Table 1 and section 6 (SURPASS-1 and SURPASS-5, 40-week trials in adults with type 2 diabetes)1; Zepbound label, Table 1 and section 6 (SURMOUNT-1 and SURMOUNT-2)2. Mounjaro's table lists reactions seen in at least 5% of people, Zepbound's in at least 2%.
What the two labels agree on
US labels caution that side-effect rates from one drug's trials cannot be directly compared with another drug's;1,2 the same logic applies to two sets of trials of one drug. On both labels, stomach effects cluster early: Mounjaro's says most nausea, vomiting and diarrhea came while the dose was being increased and eased over time; Zepbound's says most people who stopped because of side effects did so in the first few months.1,2
Both carry the same warnings, from pancreatitis and gallbladder problems to kidney problems from losing fluids. More detail: Mounjaro side effects and Zepbound side effects.1,2
In Handle
Write down how the first weeks feel
Handle's daily check-in asks about nausea every day, plus the symptoms you choose, such as diarrhea, constipation or heartburn. It is the same short card whatever you answer.
Some answers, such as severe nausea, come with a clear next step, like contacting your care team. Handle never diagnoses, and it is not a monitoring or emergency service.
- Nausea every day; other symptoms when you switch them on
- Up to six extra tracked symptoms, or one in your own words
- Symptom summaries your prescriber can read (Premium)
Doses, devices and label wording
Both brands come in the same strengths and devices, listed in the table above. The labels start low and step up gradually; your prescriber sets the steps and the amount.1,2
- Injection sites. Both labels list the abdomen or thigh, or the back of the upper arm if someone else gives the injection, and say to rotate sites with each dose.1,2
- The contraceptive pill. Both labels advise people who use one to switch to a non-oral method, or add a barrier method, for 4 weeks after starting and for 4 weeks after each dose increase.1,2
- The 2.5 mg dose. Zepbound's label says the 2.5 mg dosage "is for treatment initiation and is not approved as a maintenance dosage." Mounjaro's label used to describe 2.5 mg in a similar way, but since its August 2026 revision it no longer does, and its pharmacology section adds a modeling estimate that 2.5 mg weekly may lower HbA1c by about 1.8% after 52 weeks.1,2 That is a difference in label text, not a reason for anyone to change their dose.
- Missed doses. Each brand's instructions for use include a rule for a missed dose. Ask your prescriber or pharmacist what it means for you; Handle records what happened and never tells you to catch up.
Cost and coverage: why the brand name matters
Because the medicine is the same, the practical difference for many people in the US is coverage. Plans decide which brands they cover and usually tie that to why a medicine is prescribed, so the same molecule can be covered under one name and not the other. Prices and plan rules change often, so check with your plan or pharmacy.
In August 2024, Lilly began selling Zepbound single-dose vials, with a prescription, to people paying for themselves through its LillyDirect service.11 Handle does not sell or source medicines; it records the one you are prescribed.
Switching between Mounjaro and Zepbound
People move between the brands for ordinary reasons: a new diagnosis, a change of insurance, a move to or from the US. Whether to switch, which strength to use and when the first dose under the new name happens are your prescriber's decisions. Zepbound's label says using it with other tirzepatide-containing products, or with any GLP-1 receptor agonist, is not recommended.2
If a different medicine altogether is on the table, such as the daily tablet Foundayo, see Foundayo vs Zepbound and our guide to whether there is a Mounjaro or Zepbound pill.
What to write down if you switch
- The date, strength and injection site of your last dose under the old name
- The date and strength of your first dose under the new name
- The device, if it changes, and its storage rules
- Why you switched, such as coverage or a new diagnosis
- How you feel over the following weeks, and your weekly average weight
In Handle
One record, whatever name is on the pen
Mounjaro and Zepbound are both listed in Handle by name. When your prescriber changes your plan, you record the new one and carry on: earlier doses stay on your record under the medicine you actually took, and Journey shows the switch. More in our Mounjaro tracker and Zepbound tracker guides.
- Each dose with its amount, time and injection site
- Add a dose you forgot, up to 30 days back
- Injection-day reminders in the iPhone app
- The consultation report, a Premium feature, lists the switch too
Questions to bring to your prescriber
Whichever brand you are offered, these make a good start.
- Which brand fits the reason I am being treated, and will my plan cover it under that name?
- If my coverage or diagnosis changes, would a switch change my strength, device or injection day?
- Which side effects should I call you about, and which can I manage at home?
- Do any of my other medicines, such as insulin, a sulfonylurea or the contraceptive pill, need planning around?
- What should I do if I miss a dose?
- What would you like me to track before our next appointment?
More on getting ready: preparing for a GLP-1 doctor appointment.
Questions people ask
Is Zepbound the same as Mounjaro?+
Yes, in the way that matters most: both are tirzepatide from Eli Lilly, in the same six strengths and the same kinds of pen and vial. What differs is the approved use: in the US, Mounjaro is for type 2 diabetes and Zepbound for weight management and obstructive sleep apnea.1,2
What is the difference between Mounjaro and Zepbound?+
The brand name, the approved use and the trials each label reports. In the US, Mounjaro is Lilly's tirzepatide brand for type 2 diabetes and Zepbound its brand for weight management and sleep apnea. In the UK and EU there is no Zepbound; Mounjaro covers weight management too.1,2,3
Is Zepbound or Mounjaro better for weight loss?+
The medicine inside is the same, so the brand name does not make one better. Zepbound's label reports weight trials, such as an average 20.9% loss on 15 mg over 72 weeks in adults without diabetes (SURMOUNT-1, counting everyone randomized), against 3.1% on placebo; Mounjaro's reports diabetes trials.1,2 Your prescriber can say which fits your situation.
Is Mounjaro approved for weight loss?+
Not in the US, where tirzepatide for weight management is sold as Zepbound and Mounjaro is approved for type 2 diabetes and cardiovascular risk reduction.1,2 In the UK and EU, yes: Mounjaro itself is licensed for weight management, authorized by the UK's MHRA in November 2023.3,4
Is Zepbound available in the UK?+
Not under that name. In the UK, tirzepatide for weight management is sold as Mounjaro, authorized for that use in November 2023, with a four-dose KwikPen since January 2024.3,5 NHS access in England follows NICE's criteria and a phased rollout.6 Handle lists Mounjaro by name.
Is tirzepatide the same as Mounjaro?+
Tirzepatide is the medicine; Mounjaro and Zepbound are Eli Lilly's brand names for it. In the US the name reflects the approved use: Mounjaro for type 2 diabetes, Zepbound for weight management and sleep apnea.1,2 In the UK and EU, it is sold as Mounjaro for both.4 See our tirzepatide tracker.
Do Mounjaro and Zepbound have the same side effects?+
They share the same warnings and kinds of side effects, mostly nausea, diarrhea, vomiting and constipation. The rates differ because the trials differ: nausea affected 12–18% of people in Mounjaro's diabetes trials and 25–29% in Zepbound's 72-week weight trials, against 4% and 8% on placebo.1,2
Can you switch from Mounjaro to Zepbound?+
Your prescriber can move you from one brand to the other, for example if your coverage or diagnosis changes, and decides the strength and timing. Zepbound's label says using it with other tirzepatide-containing products is not recommended.2 Handle keeps both brands on one record, so the change is clear.
Can I track Mounjaro or Zepbound in Handle?+
Yes. Both are listed by name. Record the plan your prescriber set, then log each dose with its time and injection site, answer a short daily check-in, and keep your weight, food and fluids beside it. It is free to start. See the Mounjaro tracker and Zepbound tracker.
Sources
- Eli Lilly and Company, via DailyMed (U.S. National Library of Medicine). Mounjaro (tirzepatide) injection — Prescribing Information, effective August 27, 2026.
- Eli Lilly and Company, via DailyMed (U.S. National Library of Medicine). Zepbound (tirzepatide) injection — Prescribing Information, effective August 28, 2026.
- Medicines and Healthcare products Regulatory Agency (UK). MHRA authorises diabetes drug Mounjaro (tirzepatide) for weight management and weight loss, November 8, 2023.
- European Medicines Agency. Mounjaro — European public assessment report (EPAR).
- Medicines and Healthcare products Regulatory Agency (UK). Four-dose Mounjaro "KwikPen" approved by MHRA for diabetes and weight management, January 25, 2024.
- National Institute for Health and Care Excellence. Tirzepatide for managing overweight and obesity (TA1026), published December 23, 2024; updated September 1, 2025.
- U.S. Food and Drug Administration. FDA Approves New Medication for Chronic Weight Management, November 8, 2023.
- U.S. Food and Drug Administration. FDA Approves First Medication for Obstructive Sleep Apnea, December 20, 2024.
- U.S. Food and Drug Administration. Drugs@FDA: FDA-Approved Drugs — Mounjaro, NDA 215866.
- The New England Journal of Medicine, via PubMed. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1), 2022.
- Eli Lilly and Company, via PR Newswire. Lilly releases Zepbound (tirzepatide) single-dose vials, expanding supply and access for adults living with obesity, August 27, 2024.
- U.S. Food and Drug Administration (Drug Safety Communication). FDA Requests Removal of Suicidal Behavior and Ideation Warning from Glucagon-Like Peptide-1 Receptor Agonist (GLP-1 RA) Medications, January 13, 2026.
Written by the Handle team from the sources above, last checked on September 23, 2026. How we write: our editorial policy. Spotted something out of date? Tell us at [email protected].
Handle supports recording and conversations with your care team. It does not diagnose, and it never tells you to start, change, skip or stop a dose. This page is general information, not medical advice. Always follow your prescriber and your medicine's instructions for use.