Tirzepatide dosage: doses, schedule and units to mg

The labeled tirzepatide ladder

Two FDA-approved brands contain tirzepatide, Zepbound and Mounjaro, and each begins at 2.5 mg a week. This is the ladder in the Zepbound label, which covers weight management and sleep apnea ^[1]:

Zepbound dose steps (label Section 2)

Step	When	Weekly dose	What the label says
1	Weeks 1 to 4	2.5 mg	Starter dose; not approved for maintenance
2	Week 5 onward	5 mg	First maintenance option for weight
3	4 or more weeks later, if needed	7.5 mg	Intermediate step
4	4 or more weeks later, if needed	10 mg	Maintenance option for weight and sleep apnea
5	4 or more weeks later, if needed	12.5 mg	Intermediate step
6	4 or more weeks later, if needed	15 mg	Maintenance option and the ceiling

Sleep apnea uses only the top two maintenance options, 10 mg or 15 mg ^[1]. Mounjaro, the type 2 diabetes brand, opens the same way and adds 2.5 mg after 4 or more weeks when blood sugar needs more control, but it names no maintenance set. Its ceiling is 15 mg in adults and 10 mg in children aged 10 and up ^[2]. Brand detail lives on Zepbound dosage and Mounjaro dosage.

Top, bottom and in between

• Top: 15 mg a week ^[1].
• Bottom: 2.5 mg, the starter. Nothing smaller appears on the label, so a figure like 1.5 mg is an off-label amount ^[1]. See microdosing tirzepatide.
• Typical or therapeutic: the label names no average. For weight it lists 5, 10 and 15 mg as maintenance options ^[1].
• Skipping straight to 5 mg: not on the label, which puts everyone on 2.5 mg for the first 4 weeks ^[1].
• Moving up after 2 weeks: the label wants each dose held for 4 weeks or more before the next ^[1].

More milligrams, more weight loss?

In SURMOUNT-1 the average answer was yes: weight fell by 15.0% on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg over 72 weeks ^[3]. Vomiting climbed with dose too, at 8%, 11% and 13% ^[4]. Stuck at 5 mg or 7.5 mg? The label permits another 2.5 mg step once you have spent 4 or more weeks on the current dose ^[1], though 7.5 mg itself is a step rather than a listed maintenance option. Trial detail is on tirzepatide results.

Units, mL and mg: why we publish no chart

Brand pens and vials

Brand products are already dosed in mg, so there is nothing to convert. A single-dose pen or single-dose vial delivers one dose, 2.5 to 15 mg, in 0.5 mL. A KwikPen or a multi-dose vial carries 4 doses of 0.6 mL ^[1]. If you draw from a vial, the syringe must be able to measure 0.5 mL or 0.6 mL, and each shot needs a fresh syringe and needle ^[1].

Compounded vials

Compounded tirzepatide is not FDA-approved, and FDA does not look at it for safety, effectiveness or quality ^[5]. The compounding pharmacy decides its strength. That is why units cannot be translated into mg in general: the answer comes from the mg per mL printed on your vial's pharmacy label. Go by your prescriber's written dose and that label, and ask the pharmacist to confirm before you inject. A refill, or a vial from a different pharmacy, can pack a different amount into the same number of units, so we leave units charts off this site. The same logic answers "is 50 units a lot": only the concentration can say.

Measuring mistakes have hurt people. FDA has reports of adverse events, some ending in hospital stays, after patients mismeasured compounded injectable semaglutide and after clinicians miscalculated doses ^[5]. Compounded tirzepatide vials ask you to do the same measuring. More on compounded tirzepatide.

Weekly timing, split doses and half doses

Tirzepatide is a once-a-week shot. Moving your shot day is fine when the two doses sit 3 days (72 hours) or more apart ^[1]. Split doses, half doses and two shots a week are not in the label, and the trials gave one full dose per week. Check with your prescriber before changing the pattern. For a late dose, the window is 4 days (96 hours); past that, skip it and go back to your normal day ^[1]. Step-by-step use is on how to use tirzepatide.

Shelf life of a vial

A brand single-dose vial may spend up to 21 days in total out of the fridge, at no more than 86°F. A brand multi-dose vial is finished 30 days after you first use it, or after 4 weekly doses, whichever is first, even with liquid left ^[6]. Compounded vials follow their pharmacy label; for compounded multi-dose GLP-1 vials, FDA's general guidance is to throw them out 28 days after first use ^[5]. Details on tirzepatide storage.

Does a bigger dose speed up metabolism?

The label's mechanism section talks about GIP and GLP-1 receptors, appetite, food intake and slower stomach emptying ^[4]. It says nothing about a faster metabolism.

Price at each dose

LillyDirect prices, checked October 17, 2026: $299 a month for Zepbound 2.5 mg and $399 for 5 mg. For 7.5 to 15 mg it is $449 when you refill within 45 days; outside that window, $499 for 7.5 mg and $699 for 10 to 15 mg ^[7]. Compounded prices depend on the seller; compare them on tirzepatide cost and cheapest tirzepatide.