Zepbound is labelled in six strengths, 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg, injected once weekly. Everyone starts at 2.5 mg for four weeks, the dose may then rise in 2.5 mg increments after at least four weeks on the current step, and the approved maintenance doses for weight are 5 mg, 10 mg or 15 mg, with 15 mg the maximum for every indication.
The 2.5 mg step is the part people get wrong. The label states plainly that it is for treatment initiation and is not approved as a maintenance dosage, and it defines no shortcut past it, including for someone arriving from semaglutide. There is no Wegovy to Zepbound dose conversion on the label, which is the single most searched question about this chart.
- Six strengths: 2.5, 5, 7.5, 10, 12.5 and 15 mg once weekly. Starting dosage is 2.5 mg for four weeks.
- Approved maintenance doses are 5, 10 or 15 mg for weight, and 10 or 15 mg for obstructive sleep apnea. Maximum is 15 mg.
- The label defines no equivalence between a semaglutide dose and a tirzepatide dose, and no reduced ladder for people switching.
- Three presentations now exist: single-dose pens, single-dose vials, and four-dose multi-dose vials or KwikPens. The same milligram dose has a different concentration in each.
- A missed dose can be taken within 4 days. After that the label says to skip it, and never to take two doses within 3 days of each other.
The Zepbound dosage chart
This is the escalation schedule as the prescribing information sets it out. The week numbers assume the minimum four weeks at each step and a target of 15 mg, which is the slowest permitted climb to the highest dose rather than a plan anyone is required to follow.
| Weeks | Dose once weekly | What the label calls it |
|---|---|---|
| 1 to 4 | 2.5 mg | Starting dosage. Initiation only, not approved as maintenance |
| 5 to 8 | 5 mg | First step up. Also an approved maintenance dose for weight |
| 9 to 12 | 7.5 mg | Intermediate step. Not an approved maintenance dose |
| 13 to 16 | 10 mg | Approved maintenance dose for weight and for sleep apnea |
| 17 to 20 | 12.5 mg | Intermediate step. Not an approved maintenance dose |
| 21 onward | 15 mg | Maximum dose for all indications, and a maintenance dose |
Two features of that table are easy to miss. The approved maintenance doses are not every step: 7.5 mg and 12.5 mg exist as rungs on the ladder rather than as places to stop, so someone whose dose settles there is outside what the label describes as maintenance. And the four-week interval is a minimum, not a schedule. The label says to consider treatment response and tolerability when selecting the maintenance dosage, and that if a patient does not tolerate a maintenance dosage, a lower maintenance dosage should be considered.
Switching from Wegovy: the conversion does not exist
The reason this question comes up so much is SURMOUNT-5, the only randomised head-to-head trial between the two drugs. In 751 adults with obesity and no type 2 diabetes over 72 weeks, the maximum tolerated dose of tirzepatide produced an average 20.2% reduction in body weight against 13.7% for the maximum tolerated dose of semaglutide (PMID 40353578). People reading that result reasonably ask what their current semaglutide dose translates to.
It translates to nothing. Tirzepatide acts at both the GIP and GLP-1 receptors and semaglutide at GLP-1 alone, the milligram scales are unrelated, and the Zepbound label defines exactly one starting dosage with no adjustment for prior exposure to any other incretin medicine. The label also states that coadministration with other tirzepatide-containing products or with any GLP-1 receptor agonist is not recommended, so the two are not overlapped during a change.
What that means in practice is that the chart above is the chart for everyone, and the timing of a change is a prescriber decision rather than an arithmetic one. The semaglutide side of the comparison is laid out in our semaglutide dosage chart, and the trial results at each tirzepatide dose are in the tirzepatide dosage chart.
Three presentations, three sets of numbers
Zepbound used to mean a single-dose pen or a single-dose vial. The January 2026 label revision added a multi-dose vial and a single-patient-use KwikPen, each holding four weekly doses. The milligram dose is identical across all of them. The concentration is not.
| Dose | Single-dose pen or vial | Multi-dose vial or KwikPen | Volume injected |
|---|---|---|---|
| 2.5 mg | 2.5 mg/0.5 mL (5 mg/mL) | 10 mg/2.4 mL (4.17 mg/mL) | 0.5 mL single-dose, 0.6 mL multi-dose |
| 5 mg | 5 mg/0.5 mL (10 mg/mL) | 20 mg/2.4 mL (8.33 mg/mL) | 0.5 mL single-dose, 0.6 mL multi-dose |
| 7.5 mg | 7.5 mg/0.5 mL (15 mg/mL) | 30 mg/2.4 mL (12.5 mg/mL) | 0.5 mL single-dose, 0.6 mL multi-dose |
| 10 mg | 10 mg/0.5 mL (20 mg/mL) | 40 mg/2.4 mL (16.7 mg/mL) | 0.5 mL single-dose, 0.6 mL multi-dose |
| 12.5 mg | 12.5 mg/0.5 mL (25 mg/mL) | 50 mg/2.4 mL (20.8 mg/mL) | 0.5 mL single-dose, 0.6 mL multi-dose |
| 15 mg | 15 mg/0.5 mL (30 mg/mL) | 60 mg/2.4 mL (25 mg/mL) | 0.5 mL single-dose, 0.6 mL multi-dose |
Why that matters for anyone drawing from a vial
A pen and a KwikPen meter their own dose, so the concentration column is background information. A vial does not, and the label instructs prescribers to tell patients to use a syringe appropriate for the dose, naming a 1 mL syringe capable of measuring 0.5 mL or 0.6 mL.
Take the 5 mg dose as the worked example. In a single-dose vial it is 10 mg/mL, so 5 mg occupies 0.5 mL, which is 50 marks on a U-100 syringe. In a multi-dose vial it is 8.33 mg/mL, so the same 5 mg occupies 0.6 mL, which is 60 marks. Same prescription, same milligrams, different volume, because the two containers are formulated differently. A unit number remembered from one presentation is wrong on the other, and that failure mode is exactly the one documented in the poison-centre case series on GLP-1 dosing errors. The arithmetic is in our mg to units explainer, and there is a worked example for the 2.5 mg tirzepatide dose specifically.
The label adds one restriction specific to the new device: the KwikPen is not recommended for self-administration by people who are visually impaired.
Sleep apnea starts the maintenance range higher
Zepbound carries two indications. Alongside weight reduction and long-term weight maintenance, it is approved to treat moderate to severe obstructive sleep apnea in adults with obesity. The escalation schedule is the same for both, starting at 2.5 mg, but the approved maintenance range is narrower for sleep apnea: 10 mg or 15 mg, with 5 mg not included. The maximum is 15 mg either way.
Missed doses and moving your injection day
The label gives two numerical rules, and they are worth knowing before the situation arises rather than during it:
- A missed dose can be taken as soon as possible within 4 days, or 96 hours, of when it was due, after which the regular weekly schedule resumes.
- If more than 4 days have passed, the label says to skip that dose and take the next one on the regularly scheduled day.
- The weekly injection day can be changed as long as there are at least 3 days, or 72 hours, between two doses.
Those rules are specific to tirzepatide and do not transfer. Each GLP-1 label sets its own window, and the semaglutide products use a different one, so a rule carried over from a previous drug is not safe to assume.
What a dosage chart cannot tell you
The chart is a schedule of licensed strengths. It says nothing about what any particular dose achieves, which is a trial question rather than a label one, and SURMOUNT-1 measured outcomes at 5 mg, 10 mg and 15 mg rather than across all six. It also says nothing about where your own dose should settle: three of the six strengths are approved maintenance doses for weight, and which of the three fits is a judgement about response and tolerability that belongs with your prescriber.
Mounjaro contains the same molecule on a different label, with the dose driven by glucose control rather than weight, which we cover in the Mounjaro dosage chart.
See what each dose produced in the trials
Put your starting weight against the tirzepatide results and get a pound figure for 5, 10 and 15 mg.
FAQ
What is the Zepbound dose conversion from Wegovy?
There is not one. The Zepbound label defines a single starting dosage of 2.5 mg once weekly for four weeks, with no adjustment for people who have taken semaglutide or any other GLP-1 before. The two molecules act on different receptor combinations and their milligram scales are unrelated, so no equivalence table exists. The timing of a change is a prescriber decision.
What are the six Zepbound doses?
2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg and 15 mg, each injected once weekly. The label treats 2.5 mg as initiation only and names 5 mg, 10 mg and 15 mg as the approved maintenance doses for weight, which leaves 7.5 mg and 12.5 mg as intermediate steps.
How long does it take to reach 15 mg?
At the labelled minimum of four weeks per step, 15 mg is reached in week 21. That is the fastest schedule the label permits rather than a target, since it also says to consider response and tolerability when selecting a maintenance dose and to consider a lower one if a dose is not tolerated.
Is the Zepbound vial the same dose as the pen?
The milligram dose is the same, but the concentration is not the same across all presentations. Single-dose pens and single-dose vials hold the dose in 0.5 mL, while the multi-dose vial and the KwikPen hold four doses of 0.6 mL at a lower concentration. A 5 mg dose is 0.5 mL from a single-dose vial and 0.6 mL from a multi-dose vial.
What happens if you miss a Zepbound dose?
The label says a missed dose can be taken within 4 days, or 96 hours, of when it was due. If more than 4 days have passed, that dose is skipped and the next one is taken on the regularly scheduled day. Two doses should never be taken within 3 days of each other.
Is 7.5 mg a maintenance dose?
Not according to the label. For weight reduction and long-term maintenance the approved maintenance doses are 5 mg, 10 mg and 15 mg. For obstructive sleep apnea they are 10 mg and 15 mg. 7.5 mg and 12.5 mg appear only as steps in the escalation schedule.
This article describes the contents of a published product label. It is not medical advice and not a dosing instruction. Do not start, change, split or stop a dose based on anything here. Your dose and your schedule are decisions for your prescriber.
Sources
- Eli Lilly. ZEPBOUND (tirzepatide) injection, for subcutaneous use. US prescribing information, sections 1, 2.1, 2.2, 2.3, 2.4 and 3, revised January 2026.
- Aronne LJ, Horn DB, le Roux CW, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity (SURMOUNT-5). <em>N Engl J Med</em>. 2025;393(1):26-36. PMID: 40353578
- Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). <em>N Engl J Med</em>. 2022;387(3):205-216. PMID: 35658024
- Lambson JE, Flegal SC, Johnson AR. Administration errors of compounded semaglutide reported to a poison control center: case series. <em>J Am Pharm Assoc</em>. 2023;63(5):1643-1645. PMID: 37392810