Tirzepatide dosage
Tirzepatide is the dual GIP/GLP-1 agonist sold as Zepbound and Mounjaro. The FDA label starts at 2.5 mg once a week for 4 weeks, moves to 5 mg, and then allows 2.5 mg steps after at least 4 weeks at each dose, up to 15 mg. The 2.5 mg dose is for starting only, not maintenance. Research vials use the same ladder, and most people maintain somewhere between 5 mg and 10 mg.
Basis: FDA label. 2.5 mg for 4 weeks, then 5 mg; increase in 2.5 mg steps after at least 4 weeks on the current dose; maintenance 5, 10 or 15 mg; 15 mg maximum
- How often
- once weekly
- When
- any time of day, with or without food; keep at least 3 days between doses if you move the day
- How long
- continuous while in use; the SURMOUNT trials ran 72 weeks and weight returns after stopping
- Route
- subcutaneous, abdomen or thigh, or the back of the upper arm if someone else injects; rotate sites
- Storage
- single-dose pens and vials: fridge at 2 to 8 C, or up to 21 days at room temperature below 30 C (FDA label); multi-dose vial: discard 30 days after first use; lyophilized research vials: fridge or freezer, reconstituted in the fridge and commonly used within 4 weeks (commonly reported)
Dose ranges by source
| Range | Per | Basis | Note |
|---|---|---|---|
| 2.5 mg to 15 mg | week | FDA label | 2.5 mg for 4 weeks, then 5 mg; increase in 2.5 mg steps after at least 4 weeks on the current dose; maintenance 5, 10 or 15 mg; 15 mg maximum |
| 2.5 mg to 15 mg | week | commonly reported | compounded and research-vial users copy the label ladder; many stop climbing at 5 mg or 7.5 mg if weight is moving |
Titration schedule
Step up on this schedule; stay a step longer if side effects are rough.
| Weeks | Dose |
|---|---|
| 1-4 | 2.5 mg |
| 5-8 | 5 mg |
| 9-12 | 7.5 mg (optional step) |
| 13-16 | 10 mg |
| 17-20 | 12.5 mg (optional step) |
| 21 onward | 15 mg maximum; stay at 5 or 10 mg if that is working |
Tirzepatide dose to units chart
10 mg vial + 1 mL bacteriostatic water = 10 mg/mL (100 mcg per unit on a U-100 insulin syringe). 10 mg + 1 mL = 10 mg/mL, so 2.5 mg = 0.25 mL = 25 units; 5 mg = 50 units, 7.5 mg = 75 units. For 10 mg and above use a 2 mL reconstitution on a 20 mg or larger vial or draw twice.
| Dose | mL | Units (U-100) | Doses per vial |
|---|---|---|---|
| 2.5 mg | 0.25 | 25 | 4 |
| 5 mg | 0.5 | 50 | 2 |
| 7.5 mg | 0.75 | 75 | 1 |
| 10 mg | 1 | 100 | 1 |
| 12.5 mg | 1.25 | 125 | 0 |
| 15 mg | 1.5 | 150 | 0 |
| 20 mg | 2 | 200 | 0 |
Different vial or water? Full 10 mg + 1 mL table or set your own numbers below.
Commonly stacked with
- Cagrilintide 0.3 mg to 4.5 mg
Side effects
- nausea
- diarrhea
- decreased appetite
- vomiting
- constipation
- dyspepsia
- abdominal pain
- injection site reactions
- fatigue
- burping
- hair loss
- reflux
Tirzepatide dosage questions
How many units is 2.5 mg of tirzepatide?
It depends on the vial. A 10 mg vial reconstituted with 1 mL is 10 mg/mL, so 2.5 mg is 25 units on a U-100 syringe and 5 mg is 50 units. A 10 mg vial with 2 mL is 5 mg/mL, so 2.5 mg becomes 50 units. Always run the math for your own vial.
Tirzepatide dosage chart by week?
Label schedule: 2.5 mg for weeks 1 to 4, 5 mg for weeks 5 to 8, then optional 2.5 mg steps every 4 or more weeks through 7.5, 10, 12.5 and 15 mg. You do not have to climb; 5, 10 and 15 mg are all approved maintenance doses. Many people hold at 5 mg or 7.5 mg as long as weight keeps moving.
Can you stay on 2.5 mg of tirzepatide?
The label says 2.5 mg is for treatment initiation only and is not approved as a maintenance dose. In practice some people hold there longer because it is working, but the trials that produced the published weight numbers used 5 mg and up. If 2.5 mg is enough for you, that is a conversation with your clinician, not a label-backed plan.
What is the max dose of tirzepatide?
15 mg once weekly for adults, for both Zepbound and Mounjaro. The label requires at least 4 weeks at each lower step before going up. Going past 15 mg has no published data.
Sources
- Zepbound (tirzepatide) prescribing information, FDA, 2026 revision (217806s042)
- Mounjaro (tirzepatide) prescribing information, FDA, 2026 revision (215866s044s045)
- FDA, Concerns with unapproved GLP-1 drugs used for weight loss (compounded dosing errors)
Brands we recommend for Tirzepatide. We are independent and have no affiliation with any brand: no affiliate links, no referral codes, no paid placements. These are the suppliers whose testing and certificates hold up when we check them.
- Licensed Peptides two accredited labs on every lot, certificates public, card and Apple Pay checkout
- Core Peptides long track record, public certificates, wide catalog
- Ascension Peptides public third-party testing, clear pricing
This page is an educational summary of published labels, trials and commonly reported use. It is not medical advice and does not replace a clinician.