Tirzepatide Dosing (Zepbound, Mounjaro): 2.5 mg to 15 mg, From the FDA Labels

Tirzepatide is injected under the skin once a week. Zepbound (tirzepatide) starts at 2.5 mg weekly for 4 weeks; its label, revised August 2026, says 2.5 mg is for starting treatment, not maintenance.1 Zepbound then goes up to 5 mg weekly, and may rise in 2.5 mg steps after at least 4 weeks on the current dose, to the 15 mg weekly maximum.1 Mounjaro (tirzepatide), the type 2 diabetes brand, starts at 2.5 mg weekly and rises the same way if more blood-sugar control is needed (Mounjaro label, August 2026).2

The steps, as the Zepbound and Mounjaro labels of August 2026 give them:1,2

1. Inject 2.5 mg once weekly for 4 weeks.1,2
2. On Zepbound, increase to 5 mg once weekly.1
3. Raise the dose in 2.5 mg steps, each after at least 4 weeks on the current dose; on Mounjaro, if more blood-sugar control is needed.1,2
4. Stop at 15 mg once weekly, the maximum for all Zepbound uses and for adults on Mounjaro.1,2

The Zepbound label names 5 mg, 10 mg and 15 mg as the maintenance doses for weight reduction and long-term weight maintenance, injected once weekly.1 Every move up or down is the prescriber's decision. A prescription for the brand starts with how to get tirzepatide online; for a late or skipped injection, use the missed-dose tool.

The Zepbound (tirzepatide) label, revised August 2026, sets the maintenance dose for weight reduction and long-term weight maintenance at 5 mg, 10 mg or 15 mg injected under the skin once weekly, and for obstructive sleep apnea at 10 mg or 15 mg once weekly.1 The maximum Zepbound dose for all indications is 15 mg once weekly.1 The Mounjaro (tirzepatide) label, also revised August 2026, caps the dose at 15 mg once weekly in adults and at 10 mg once weekly in children aged 10 years and older.2

The maintenance and maximum doses, from the Zepbound and Mounjaro labels revised August 2026:1,2

In SURMOUNT-3, a trial of 579 adults with obesity, as the Zepbound label of August 2026 reports it, 86% of Zepbound patients had a maximum tolerated dose of 15 mg weekly, and, counting everyone randomized, 21.3% of Zepbound patients versus 30.5% of placebo patients stopped the study drug.1

In SURMOUNT-1, as reported in the Zepbound (tirzepatide) label revised August 2026, adults with obesity and no diabetes lost 15.0% of body weight at week 72 on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg, versus 3.1% on placebo, counting everyone who started.1 The share who lost at least 20% of body weight at week 72 was 30.0% on 5 mg, 50.1% on 10 mg and 56.7% on 15 mg, versus 3.1% on placebo.1

The table is from SURMOUNT-1, a trial of 2,539 adults with obesity and no diabetes, as the Zepbound label of August 2026 reports it at week 72; every row counts everyone who started.1

A single-dose Zepbound or Mounjaro (tirzepatide) pen or vial holds its whole dose in 0.5 mL: the approved strengths are 2.5, 5, 7.5, 10, 12.5 and 15 mg per 0.5 mL, as the FDA's Federal Register notice of May 1, 2026 lists them.3 A multi-dose KwikPen or vial holds four doses in 2.4 mL, from 10 mg/2.4 mL (four 2.5 mg doses) to 60 mg/2.4 mL (four 0.6 mL doses of 15 mg).3 The notice and the Zepbound label give each dose in mg and mL, not in units.3,1

The Zepbound label of August 2026 tells vial users to draw up each dose with a 1 mL syringe that can measure a 0.5 mL or 0.6 mL dose, and to use a new syringe and needle for every injection.1

The approved single-dose strengths, as the FDA notice of May 1, 2026 lists them:3

A dose written in other units, or for a vial of another strength, goes through the dose converter, which turns it into mg and lines it up with these steps.

Not always. The FDA has adverse event reports from patients prescribed compounded semaglutide or tirzepatide at doses beyond the approved label: larger single doses, more frequent dosing and faster titration, with nausea, vomiting, diarrhea, abdominal pain and constipation (FDA alert, updated September 1, 2026).5 In a Federal Register notice of May 1, 2026, the FDA noted that nominators proposed compounded tirzepatide injections from 2.5 up to 30 mg per 0.5 mL; the 20 and 30 mg per 0.5 mL strengths exceed any approved product and came with no supporting data.4

For a patient who needs a lower dose than the pens give, the FDA said in the same notice that the nominations did not show why the approved 2.5 mg per 0.5 mL product, or smaller volumes drawn from the approved vials, could not be used instead.4 Side by side, the two routes are on compounded tirzepatide vs Mounjaro.

This article is for information only and is not medical advice. Talk to a licensed clinician before you start, change or stop a medicine.