Dosage chart · 2026

Tirzepatide dosage chart

Mounjaro and Zepbound are the same molecule — tirzepatide — on the same weekly schedule: 2.5 mg up to 15 mg, one step every 4 weeks. Here is every dose, what each step is for, and why it always starts at a dose that barely works.

The chart: week by week

When	Dose (weekly)	What it is
Weeks 1–4	2.5 mg	Starting / tolerance dose (not a treatment dose)
Weeks 5–8	5 mg	First maintenance option
Weeks 9–12	7.5 mg	Titration step
Weeks 13–16	10 mg	Second maintenance option
Weeks 17–20	12.5 mg	Titration step
Week 21+	15 mg	Top dose (max average loss in SURMOUNT-1)

Each step is held ~4 weeks before increasing. Many people stop at 5 or 10 mg if it works — 15 mg is the top dose, not a required destination.

Why it starts at 2.5 mg

The 2.5 mg starting dose is sub-therapeutic by design — too low to drive much weight loss, chosen only to build tolerance and blunt the nausea, vomiting, and diarrhea a higher start would cause. That is why the first month feels underwhelming: you are on a tolerance dose, not the treatment dose. See the week-by-week experience in the Zepbound timeline.

Mounjaro vs Zepbound — same schedule

Mounjaro (type 2 diabetes) and Zepbound(weight loss) are the identical molecule on the identical 2.5→15 mg titration — the difference is the on-label indication, not the dose ladder. For semaglutide’s schedule instead, see the semaglutide dosage chart; to understand why tirzepatide (a dual GIP/GLP-1 agonist) tends to out-lose semaglutide, read what is a GLP-1.

Missed a dose?

Within 4 days (96 hours) of the missed weekly dose, take it. Past 4 days, skip it and resume on your normal day — never double up. Miss several weeks and your prescriber may re-titrate you from a lower dose. When unsure, ask.

Frequently asked questions

What is the tirzepatide dosage schedule?+

Tirzepatide (Mounjaro for diabetes, Zepbound for weight loss) is a once-weekly injection that titrates 2.5 → 5 → 7.5 → 10 → 12.5 → 15 mg, moving up one step about every 4 weeks. You start at 2.5 mg for the first 4 weeks (a tolerance dose), then 5 mg, and increase only as tolerated toward a maintenance dose of 5, 10, or 15 mg depending on response and side effects.

What is the maintenance dose of tirzepatide?+

There are three approved maintenance doses: 5 mg, 10 mg, and 15 mg once weekly. Many people do well at 5 or 10 mg; 15 mg is the top dose and produced the greatest average weight loss in the SURMOUNT-1 trial (~21%). The right maintenance dose is the lowest one that controls your appetite or blood sugar with tolerable side effects — higher is not automatically better for everyone.

Why does tirzepatide start at 2.5 mg?+

The 2.5 mg starting dose is deliberately sub-therapeutic — a tolerance-building step, not a treatment dose. Starting higher would cause much more nausea, vomiting, and diarrhea. Holding 4 weeks at each step lets your gut adapt, so by the time you reach 10 or 15 mg you can tolerate it. That is why the first month is slow: you are ramping tolerance, not yet treating at full strength.

How long to reach the full tirzepatide dose?+

Reaching 15 mg takes roughly 20+ weeks, because there are five step-ups (2.5 → 5 → 7.5 → 10 → 12.5 → 15) each held about 4 weeks. Not everyone goes all the way — many stop at 5 or 10 mg if it works. Your prescriber may hold a dose longer if you have significant GI side effects, which is normal and often smart.

What if I miss a tirzepatide dose?+

If it has been 4 days (96 hours) or fewer since the missed weekly dose, take it as soon as you remember. If more than 4 days have passed, skip it and take your next dose on the regular day — do not double up. If you miss doses for several weeks, your prescriber may restart you at a lower dose to re-titrate. Always confirm with your prescriber.

Sources

FDA — Zepbound (tirzepatide) prescribing information — titration 2.5→15 mg
FDA — Mounjaro (tirzepatide) prescribing information
Jastreboff et al., SURMOUNT-1, NEJM 2022 — 15 mg top-dose ~21% loss