Tirzepatide has six weekly doses, from 2.5 mg to 15 mg, and the label climbs them in 2.5 mg steps every four weeks or more. Tirzepatide is a GIP and GLP-1 receptor agonist,3 sold by Lilly as Zepbound for weight and as Mounjaro for type 2 diabetes.4 The chart below is the Zepbound label's schedule, with what each step costs.
Your dose, and when you move up, are set by your prescriber. This is the manufacturer's published schedule so you know what to expect. It is not a reason to change anything yourself.
The tirzepatide dosage chart
| Weekly dose | Label role | Earliest week on it |
|---|---|---|
| 2.5 mg | Starting dose only, "not approved as a maintenance dosage" | 1 |
| 5 mg | Maintenance dose for weight | 5 |
| 7.5 mg | Step up | 9 |
| 10 mg | Maintenance dose for weight and sleep apnoea | 13 |
| 12.5 mg | Step up | 17 |
| 15 mg | Maintenance dose for weight and sleep apnoea; the maximum | 21 |
Source: Zepbound label, sections 2.1 and 2.2.1 "Earliest week" assumes every step happens at the label's four-week minimum. Many people climb slower, and nothing in the label requires climbing to the top.
The rule behind the chart
In the label's words: start at "2.5 mg injected subcutaneously once weekly for 4 weeks", then "increase the dosage to 5 mg", and after that "the dosage may be increased in 2.5 mg increments, after at least 4 weeks on the current dose".1 The stated reason is "to reduce the risk of gastrointestinal adverse reactions".
Where to stop is also in the label: "Consider treatment response and tolerability when selecting the maintenance dosage. If patients do not tolerate a maintenance dosage, consider a lower maintenance dosage." For weight the maintenance doses are 5, 10 or 15 mg; for obstructive sleep apnoea, 10 or 15 mg. The maximum is 15 mg once weekly.1
Mounjaro is the same molecule, and Lilly's Mounjaro site reports results at 5 mg and 15 mg.4 The schedule quoted on this page is from the Zepbound label. If you take Mounjaro for diabetes, its own label and your prescriber govern your doses.
What the doses did in the trial
SURMOUNT-1 tested three maintenance doses for 72 weeks. Mean weight change was −15.0% at 5 mg, −19.5% at 10 mg and −20.9% at 15 mg, against −3.1% on placebo.5 The step from 5 to 10 mg added 4.5 points; the step from 10 to 15 mg added 1.4. The 7.5 and 12.5 mg doses were steps, not trial arms. Per-dose side effects are in Zepbound side effects.
What each step costs
On the brand, the dose sets the cash price. Lilly's self-pay for a Zepbound vial or KwikPen is $299 a month at 2.5 mg, $399 at 5 mg, $499 at 7.5 mg and $699 at 10, 12.5 and 15 mg.6 With a commercial plan that covers Zepbound, Lilly's card brings it to "as low as $25" at any dose.6 Here is Lilly's ladder next to the cheapest verified Zepbound seller today:
Compounded tirzepatide costs less. Some sellers hold one price at every dose and others charge more as you climb, so ask which before you pay. Today's verified prices, all in:
Compounded tirzepatide: doses in units
Compounded vials are drawn with an insulin syringe, so the dose your prescriber writes in milligrams becomes units on the syringe. How many units depends on the concentration of your vial, in mg per mL, which differs between pharmacies. The same milligram dose can be a different number of units from one vial to the next.
Use the GLP-1 dose converter: enter your dose and the concentration printed on your vial, and it gives mL and U-100 units. The arithmetic it uses is your dose in mg divided by the mg per mL, times 100. If the units on your pharmacy's instructions do not match, ask the pharmacy before you inject.
FDA has received reports of adverse events "that may be related to dosing errors" with compounded semaglutide injections, and reports tied to compounded semaglutide or tirzepatide "in doses beyond what is in the FDA-approved drug label".7 Compounded drugs "are not FDA-approved", and FDA "does not verify the safety, effectiveness or quality" of them before they are sold.8
Missed doses and storage
The Zepbound label: if a dose is missed, "administer within 4 days (96 hours) after the missed dose". If more time has passed, ask your prescriber what to do. A single-dose pen or vial can be kept out of the fridge, at up to 30°C (86°F), "for up to a total of 21 days".2 Compounded vials follow their pharmacy's instructions.
The honest summary
Four weeks at 2.5 mg, then 2.5 mg steps of at least four weeks each, stopping at the dose your prescriber and your tolerance settle on, with 15 mg the ceiling. On Lilly's self-pay prices each step up to 10 mg raises the bill; compounded sellers are cheaper and vary in whether they charge by dose. If you are on a compounded vial, get the units from the dose converter and your vial's label, every time the vial changes.