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GLP-1 dose titration: what the trials show

Nobody starts on the maintenance dose. Semaglutide and tirzepatide are both ramped up slowly — here's the actual schedule, why it exists, and what the outcome data looks like at each step.

Published 2026-08-01 · Science · 5 min read
SEC. 01

Why titration exists

GLP-1 receptor agonists cause nausea, vomiting, and slowed gastric emptying — dose-dependent side effects that are worst in the first weeks of exposure. Starting at the maintenance dose produces intolerable GI side effects in most patients. Slow titration lets the gut adapt before the dose increases again, which is why every approved schedule ramps up over months rather than starting at target.

The schedule isn't arbitrary — it's the exact protocol tested in the trials that got these drugs approved, and it's printed on the prescribing information for each medication.

SEC. 02

Tirzepatide (Mounjaro / Zepbound)

Per FDA labeling, tirzepatide starts at a dose that exists purely for tolerability — it isn't expected to produce meaningful weight loss on its own.

Weeks 1–4
2.5 MG — TOLERABILITY DOSE
Weeks 5–8
5 MG
Weeks 9–12
7.5 MG
Weeks 13–16
10 MG
Weeks 17–20
12.5 MG
Week 21+
15 MG — MAX MAINTENANCE

Each step is four weeks, and the full ramp to the highest dose takes roughly five months. Clinicians can hold at a lower maintenance dose (5 or 10 mg) if that's sufficient or better tolerated — the label doesn't require reaching 15 mg.

SEC. 03

Semaglutide (Ozempic / Wegovy)

Semaglutide's ramp is slower and finer-grained — five dose steps instead of tirzepatide's five, but at much lower absolute numbers, since semaglutide is dosed in fractions of a milligram.

Weeks 1–4
0.25 MG — TOLERABILITY DOSE
Weeks 5–8
0.5 MG
Weeks 9–12
1 MG
Weeks 13–16
1.7 MG
Week 17+
2.4 MG — MAX MAINTENANCE (WEGOVY)

Ozempic, the diabetes-indicated version of semaglutide, tops out at 2 mg rather than 2.4 mg. Both follow the same early-step schedule; only the top of the ramp differs.

SEC. 04 — WHAT THE TRIALS FOUND

In SURMOUNT-1, 72 weeks of tirzepatide produced average weight loss of roughly 16% at 5 mg, 21% at 10 mg, and 22.5% at 15 mg — a clear dose-response relationship. The head-to-head SURMOUNT-5 trial found tirzepatide outperformed semaglutide at 72 weeks, roughly −20% vs. −14% body weight.

Sources: Jastreboff et al., NEJM 2022 (SURMOUNT-1) · Aronne et al., NEJM 2025 (SURMOUNT-5) · Wilding et al., NEJM 2021 (STEP 1) · FDA prescribing information for tirzepatide and semaglutide. See SURMOUNT-5 coverage.

SEC. 05

What this means week to week

Side effects usually peak right after a dose increase — nausea in week 1 of a new dose is common and typically fades within days. If it doesn't, or gets worse, that's a signal to talk to your prescriber before the next step up, not to push through.

Skipping a week resets nothing automatically — but a long gap can mean restarting titration at a lower dose is safer than resuming at the last dose. This is a prescriber decision, not a self-adjustment.

GLP1ShotDay tracks which week and dose you're on, so the app always knows whether you're still in the ramp-up phase or on maintenance — without you having to do the math.

This article summarizes published trial data and FDA prescribing information for general education. It is not medical advice and does not replace guidance from your prescriber. Titration schedules should only be changed under clinical supervision.