Tirzepatide Dosage: Label Schedule and Trial Doses (2026)

Not dosing advice. This page reports doses that studies and approved labels used, with their sources. It does not recommend a dose, and we do not give mixing, injection or unit-conversion instructions. Gray-market vials often do not contain what their label says. How we report doses.

Every dose studied in people

Study	Who	People	Dose and route	What happened
SURPASS-CVOT (Nicholls 2025), randomized trial	Adults with type 2 diabetes and heart or blood-vessel disease	13,299	Up to 15 mg once a week, versus dulaglutide 1.5 mg Injection under the skin · Median follow-up 210.1 weeks (about 4 years)	Heart attack, stroke or cardiovascular death in 12.2% versus 13.1% on dulaglutide, an older GLP-1 drug: as good as, but not shown to be better⁸⁹.
SURMOUNT-1 (Jastreboff 2022), randomized trial	Adults with obesity, or overweight with a weight-related condition, without diabetes	2,539	5, 10 or 15 mg once a week Injection under the skin · 72 weeks, including 20 weeks of dose increases	Weight fell 15.0%, 19.5% and 20.9% on 5, 10 and 15 mg, versus 3.1% on placebo; 4.3%, 7.1% and 6.2% stopped because of side effects, versus 2.6%⁵.
SURPASS-2 (Frías 2021), open-label randomized trial	Adults with type 2 diabetes	1,879	5, 10 or 15 mg once a week, versus semaglutide 1 mg Injection under the skin · 40 weeks	HbA1c, a measure of average blood sugar, fell 2.01, 2.24 and 2.30 percentage points, versus 1.86 on semaglutide; nausea affected 17% to 22%, versus 18%¹.
SURMOUNT-2 (Garvey 2023), randomized trial	Adults with obesity or overweight and type 2 diabetes	938	10 or 15 mg once a week Injection under the skin · 72 weeks	Weight fell 12.8% and 14.7%, versus 3.2% on placebo; digestive side effects were mostly mild to moderate, and few led people to stop (under 5%)².
SURMOUNT-5 (Aronne 2025), open-label randomized trial	Adults with obesity, without type 2 diabetes	751	Highest tolerated dose, 10 or 15 mg once a week, versus semaglutide 1.7 or 2.4 mg Injection under the skin · 72 weeks	Weight fell 20.2% on tirzepatide versus 13.7% on semaglutide; digestive side effects came mainly while the dose was being raised¹⁰.
SUMMIT (Packer 2025), randomized trial	Adults with obesity and heart failure with preserved ejection fraction	731	Up to 15 mg once a week Injection under the skin · At least 52 weeks; median follow-up 104 weeks	Cardiovascular death or worsening heart failure in 9.9% versus 15.3% on placebo; 6.3% versus 1.4% stopped because of side effects¹¹.
SURMOUNT-4 (Aronne 2024), randomized withdrawal trial	Adults with obesity or overweight, without diabetes, after a 36-week lead-in on tirzepatide	670	Highest tolerated dose, 10 or 15 mg once a week, or a switch to placebo Injection under the skin · 36-week lead-in, then 52 weeks	Weight fell a further 5.5% on tirzepatide and rose 14.0% after the switch to placebo¹².
SURMOUNT-OSA (Malhotra 2024), two randomized trials	Adults with obesity and moderate to severe obstructive sleep apnea	469	Highest tolerated dose, 10 or 15 mg once a week Injection under the skin · 52 weeks	Breathing pauses during sleep fell by 25.3 and 29.3 events an hour in the two trials, versus 5.3 and 5.5 on placebo⁶.
Phase 2 trial (Frías 2018), randomized trial	Adults with type 2 diabetes	318	1, 5, 10 or 15 mg once a week, versus dulaglutide 1.5 mg or placebo Injection under the skin · 26 weeks	HbA1c fell 1.06 to 1.94 percentage points across the doses; weight, counted only while people stayed on treatment, fell 0.9 to 11.3 kg; digestive side effects rose with dose, from 23.1% on 1 mg to 66.0% on 15 mg³.

The approved schedule (Zepbound (FDA label))

The Zepbound label (version 40, effective 28 August 2026) sets one schedule for all its uses: weight reduction and long-term weight maintenance in adults, and moderate to severe obstructive sleep apnea in adults with obesity⁴. It says to raise the dose this way to reduce the risk of digestive side effects, and to consider a lower maintenance dose if one is not tolerated⁴.

When	Dose on the label	Note
Weeks 1 to 4	2.5 mg once a week	Starting dose only; not approved as a maintenance dose
Week 5 onward	5 mg once a week	The lowest maintenance dose
After at least 4 weeks on each dose	Increases of 2.5 mg: 7.5, 10, 12.5, then 15 mg once a week	Only until the chosen maintenance dose is reached
Maintenance, weight reduction	5, 10 or 15 mg once a week	Chosen by response and tolerability
Maintenance, sleep apnea	10 or 15 mg once a week
Maximum, all uses	15 mg once a week

Studies, animals and users: kept apart

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Zepbound label (weight loss and sleep apnea): start at 2.5 mg injected under the skin once weekly for 4 weeks, then increase in 2.5 mg steps, at least 4 weeks apart, until the maintenance dose is reached. Maintenance is 5, 10 or 15 mg weekly for weight (10 or 15 mg for sleep apnea); 2.5 mg is for starting only, and the maximum is 15 mg weekly⁴. Mounjaro label (type 2 diabetes): start at 2.5 mg weekly and increase in 2.5 mg steps after at least 4 weeks if needed; maximum 15 mg weekly in adults and 10 mg in children 10 and older¹⁴. Since 27 August 2026 the Mounjaro label allows 2.5 mg for ongoing blood sugar control¹⁵. The trials used the same range: fixed 5, 10 or 15 mg weekly in SURMOUNT-1, and the maximum tolerated dose of 10 or 15 mg, or up to 15 mg, in the sleep apnea, heart and heart-failure trials⁵⁶⁸¹¹. Phase 1 tested single doses of 0.25 to 8 mg, 4-week courses of 0.5 to 10 mg in healthy volunteers and 0.5 to 15 mg in people with type 2 diabetes, with doses above 5 mg reached by stepping up¹⁶.

In animal studies

Rats: 0.15, 0.50 and 1.5 mg/kg injected under the skin twice weekly for 2 years; thyroid C-cell adenomas and carcinomas combined rose at all doses⁴. rasH2 transgenic mice: 1, 3 and 10 mg/kg twice weekly for 6 months; it did not cause tumors⁴. Rat fertility studies: 0.5, 1.5 and 3 mg/kg twice weekly; no effect on mating, fertility or conception, but female rats had fewer implantation sites and viable embryos at all doses, which the label attributes to lower food intake and body weight⁴. These are animal safety-study doses, not human doses.

What users report Anecdotal · not validated · not a recommendation

A 2026 journal commentary says “microdosing” of single- and dual-receptor GLP-1 drugs (tirzepatide is a dual agonist) is typically defined as 25% to 50% of the manufacturer’s recommended starting dose, or longer intervals between doses. It says the practice spread through patient communities, telehealth weight-loss programs and clinician anecdotes, and that high-quality evidence is essentially absent¹³.

Half-life and how it is taken

Half-life: About 5 to 6 days⁴Adults with overweight or obesity, including those with sleep apnea, after subcutaneous injection (Zepbound label, clinical pharmacology section); the same label’s overdose section rounds it to about 5 days. Tirzepatide is 99% bound to albumin.
Routes: Subcutaneous injection, once weekly (the only approved route and the route used in all trials cited here)

Why the dose goes up slowly

The label says the dose goes up in steps to reduce the risk of digestive side effects such as nausea, vomiting and diarrhea⁴. In the two main weight-loss trials behind the label, digestive side effects affected 56% of people on each dose versus 30% on placebo, and most nausea, vomiting and diarrhea came while the dose was being raised and eased over time⁴. Most people who stopped because of side effects did so in the first few months⁴.

Tirzepatide slows the emptying of the stomach, an effect that is largest after the first dose and fades over time⁴. Blood levels settle at a steady level after 4 weeks of weekly doses⁴. In SURMOUNT-1, the 72-week trial included a 20-week period of dose increases⁵.

In a 26-week phase 2 trial in type 2 diabetes, digestive side effects rose with the dose: 23.1% of people on 1 mg, 32.7% on 5 mg, 51.0% on 10 mg and 66.0% on 15 mg, versus 9.8% on placebo³. In the two weight-loss trials behind the label, stopping for digestive side effects rose with the dose even though the side effects were equally common⁴. It went from 1.9% of people on 5 mg to 3.3% on 10 mg and 4.3% on 15 mg, versus 0.5% on placebo⁴. The label also advises anyone taking birth-control pills to switch to a non-oral method or add a barrier method for 4 weeks after starting and after each dose increase, because the slower stomach emptying may make the pills less effective⁴.

What happens if you miss a dose (per the label)

The Zepbound label says to take a missed dose as soon as possible within 4 days (96 hours)⁴. If more than 4 days have passed, it says to skip that dose, take the next one on the usual day and carry on once a week⁴. The weekly dose day can be changed as long as doses are at least 3 days (72 hours) apart⁴.

The Mounjaro label gives the same rules¹⁴. Neither label has a separate rule for several missed doses in a row, unlike the Wegovy label for semaglutide, which says to restart the dose increases from a lower dose after 2 or more missed doses in a row⁴¹⁴¹⁷.

The Mounjaro schedule for type 2 diabetes

Mounjaro is tirzepatide approved for type 2 diabetes in adults and children 10 and older, and for lowering the risk of heart attack, stroke and cardiovascular death in adults with type 2 diabetes at high risk¹⁴. Its label (version 40, effective 27 August 2026) also starts at 2.5 mg once a week, and allows increases of 2.5 mg after at least 4 weeks on the current dose if more blood-sugar control is needed¹⁴.

The maximum is 15 mg once a week for adults and 10 mg for children 10 and older¹⁴. Unlike Zepbound, whose label calls 2.5 mg a starting dose only, Mounjaro’s label has allowed 2.5 mg as an ongoing dose since 27 August 2026⁴¹⁴¹⁵.

Why gray-market vials make doses unreliable

Every dose on this page comes from trials and labels of Lilly’s approved medicine⁴⁵. Online sellers also offer “research use only” tirzepatide vials, which FDA says are sold for human use with dosing instructions¹⁸. FDA has also found fraudulent compounded tirzepatide whose labels name pharmacies that do not exist or did not make the product¹⁸.

Independent tests show how far such products can drift⁷¹⁹. Of Finnrick’s latest 196 completed tirzepatide tests, 59 failed (30.1%) as of 30 September 2026⁷. Its default pass mark allows the measured amount to differ from the label by up to 35%, so a vial can pass while holding about a third more or less than it says⁷¹⁹. Finnrick’s results come from users who chose to send samples, not from a random sample of the market⁷²⁰.

Some fakes hold a different drug: lab tests on two counterfeit tirzepatide pens detained in Ireland in 2025 found insulin instead of tirzepatide, which can cause severe low blood sugar (hypoglycemia)²¹.

Questions people ask

How much tirzepatide should I take?

For the approved medicine, the Zepbound label starts at 2.5 mg once a week for 4 weeks and sets a maintenance dose of 5, 10 or 15 mg once a week, with 15 mg as the maximum⁴. The main weight-loss trials used the same range⁵¹⁰. Ask your prescriber which dose, if any, fits you.

What is the maximum dose of tirzepatide?

15 mg once a week, on both the Zepbound label and the Mounjaro label for adults⁴¹⁴. For children 10 and older with type 2 diabetes, the Mounjaro maximum is 10 mg once a week¹⁴.

How long do you stay on each tirzepatide dose?

At least 4 weeks: the Zepbound label starts with 4 weeks at 2.5 mg, and each 2.5 mg increase comes after at least 4 weeks on the current dose⁴. At that pace, reaching 15 mg takes at least 20 weeks, matching the 20-week period of dose increases in SURMOUNT-1⁴⁵.

Is 2.5 mg of tirzepatide enough to lose weight?

It is not approved for that: the Zepbound label uses 2.5 mg only to start treatment, not as a maintenance dose⁴. The lowest maintenance dose, 5 mg, cut weight by 15.0% at 72 weeks in SURMOUNT-1, versus 3.1% on placebo⁵. The Mounjaro label, which is for type 2 diabetes, has allowed 2.5 mg as an ongoing dose since 27 August 2026¹⁵.

What happens when you stop taking tirzepatide?

In SURMOUNT-4, people switched to placebo after 36 weeks on tirzepatide saw their weight rise 14.0% over the next 52 weeks, while those who stayed on it lost a further 5.5%¹². At the end, 89.5% of those who stayed on it had kept at least 80% of their earlier weight loss, versus 16.6% of those switched to placebo¹².

Go deeper

Sources

1Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 Diabetes New England Journal of Medicine, 5 Aug 2021. pubmed.ncbi.nlm.nih.gov
2Tirzepatide once weekly for the treatment of obesity in people with type 2 diabetes (SURMOUNT-2): a double-blind, randomised, multicentre, placebo-controlled, phase 3 trial The Lancet, 19 Aug 2023. pubmed.ncbi.nlm.nih.gov
3Efficacy and safety of LY3298176, a novel dual GIP and GLP-1 receptor agonist, in patients with type 2 diabetes: a randomised, placebo-controlled and active comparator-controlled phase 2 trial The Lancet, 17 Nov 2018. pubmed.ncbi.nlm.nih.gov
4ZEPBOUND (tirzepatide) injection, for subcutaneous use: prescribing information Eli Lilly and Company via DailyMed (U.S. National Library of Medicine), 28 Aug 2026. dailymed.nlm.nih.gov
5Tirzepatide Once Weekly for the Treatment of Obesity New England Journal of Medicine, 21 Jul 2022. pubmed.ncbi.nlm.nih.gov
6Tirzepatide for the Treatment of Obstructive Sleep Apnea and Obesity New England Journal of Medicine, 3 Oct 2024. pubmed.ncbi.nlm.nih.gov
7Tirzepatide: vendor test results Finnrick, 29 Sep 2026. finnrick.com
8Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 Diabetes New England Journal of Medicine, 18 Dec 2025. pubmed.ncbi.nlm.nih.gov
9FDA approves Lilly’s Mounjaro (tirzepatide) to reduce cardiovascular risk in adults with type 2 diabetes Eli Lilly and Company (PR Newswire), 28 Aug 2026. prnewswire.com
10Tirzepatide as Compared with Semaglutide for the Treatment of Obesity New England Journal of Medicine, 3 Jul 2025. pubmed.ncbi.nlm.nih.gov
11Tirzepatide for Heart Failure with Preserved Ejection Fraction and Obesity New England Journal of Medicine, 30 Jan 2025. pubmed.ncbi.nlm.nih.gov
12Continued Treatment With Tirzepatide for Maintenance of Weight Reduction in Adults With Obesity: The SURMOUNT-4 Randomized Clinical Trial JAMA, 2 Jan 2024. pubmed.ncbi.nlm.nih.gov
13Considerations and challenges in microdosing of GLP-1-based receptor agonists Expert Opinion on Pharmacotherapy, 5 Oct 2026. pubmed.ncbi.nlm.nih.gov
14MOUNJARO (tirzepatide) injection, for subcutaneous use: prescribing information Eli Lilly and Company via DailyMed (U.S. National Library of Medicine), 27 Aug 2026. dailymed.nlm.nih.gov
15Supplement approval letter, NDA 215866/S-044 and S-045 (Mounjaro) U.S. Food and Drug Administration, 27 Aug 2026. accessdata.fda.gov
16LY3298176, a novel dual GIP and GLP-1 receptor agonist for the treatment of type 2 diabetes mellitus: From discovery to clinical proof of concept Molecular Metabolism, Dec 2018. pubmed.ncbi.nlm.nih.gov
17WEGOVY (semaglutide) injection and tablets: prescribing information (SPL version 19) Novo Nordisk via DailyMed (U.S. National Library of Medicine), 30 Jun 2026. dailymed.nlm.nih.gov
18FDA’s Concerns with Unapproved GLP-1 Drugs Used for Weight Loss U.S. Food and Drug Administration, 1 Oct 2026. fda.gov
19Methodology Finnrick, accessed 30 Sep 2026. finnrick.com
20We’d Rather Buy the Future Than Wait For It Finnrick, 10 Jun 2026. finnrick.com
21HPRA health warning after detention of counterfeit tirzepatide pens containing insulin Health Products Regulatory Authority (Ireland), 10 Oct 2025. hpra.ie

Not medical advice. Talk to a licensed clinician before using any drug. Report an error.