Retatrutide timeline: the week-by-week published record. | Reddit

No single trial publishes a week-by-week curve. What exists is a set of fixed timepoints scattered across the published trial reports, and lining them up in one table is the most honest version of a timeline the record allows. Every row below is a published readout from a human trial, except the steady-state row, which is arithmetic and labelled as such.

Titration. The phase 2 obesity trial assigned initial doses of 2 mg or 4 mg against final targets up to 12 mg, and its abstract records that gastrointestinal adverse events were dose-related, mostly mild to moderate, and partially mitigated with the lower 2 mg start. The phase 2 diabetes trial went further and made escalation pace itself a variable, running slow and fast escalation arms to the same 8 mg target.

A widely shared dose-ladder video claims the steps were 2, 4, 6, 9 and 12 mg at 4-week intervals. That is a creator claim: the published abstracts confirm stepwise escalation but do not publish the step calendar, and the dose lists that are published differ from the video’s ladder. The full comparison sits in our retatrutide half-life article.

Roughly weeks 4 to 5 for any given dose level, by arithmetic rather than by a published readout: the phase 1b trial put the half-life at approximately 6 days, and the standard rule holds that steady state arrives after 4 to 5 half-lives of regular dosing. Because the trials kept escalating, each new dose level restarted that climb, so a participant titrating stepwise reaches steady state on the final dose only after the last escalation step, well into the trial.

The phase 1b trial is the 12-week checkpoint: once-weekly dosing in people with type 2 diabetes produced a placebo-adjusted bodyweight reduction of up to 8.96 kg in the group that escalated through 3, 6, 9 and 12 mg. Behind it sits the single-dose signal from the phase 1 program, a bodyweight reduction persisting to day 43 after one injection. Those two numbers are the entire published record before week 24, which is worth remembering when a post describes a detailed month-by-month arc. Onset specifics are covered in how long retatrutide takes to work.

Week 24 is the densest point in the record: the obesity trial’s interim weight numbers, the diabetes trial’s primary endpoint, and the liver-fat substudy’s primary endpoint all land here.

The diabetes program owns this stretch. Bodyweight in the phase 2 diabetes trial fell dose dependently through week 36, from 3.19% on 0.5 mg to 16.34 to 16.94% in the higher-dose groups. Two substudies measured at the same mark: the body-composition substudy tracked percent change in total fat mass to week 36 against both placebo and dulaglutide, and the appetite analysis scored appetite and eating behaviour at 24 and 36 weeks in 275 adults.

TRANSCEND-T2D-1, published in The Lancet in 2026, is the first phase 3 readout: 537 adults with type 2 diabetes not controlled by diet and exercise, across 48 sites in the USA, Mexico and India, randomised to once-weekly retatrutide 4, 9 or 12 mg or placebo for 40 weeks. Phase 3 numbers in a diabetes population run lower than the phase 2 obesity figures, which is a population difference to keep in view when comparing rows in the timeline table.

Week 48 is where the numbers everyone quotes live: least-squares mean weight change of -8.7% on 1 mg, -17.1% on 4 mg, -22.8% on 8 mg and -24.2% on 12 mg, against -2.1% for placebo, in the phase 2 obesity trial. The liver-fat substudy’s design also ran to 48 weeks, with its primary endpoint reported at 24.

If retatrutide interests you because you are already on a GLP-1, the 48-week numbers are also the ones circulating in switching discussions; our switching from tirzepatide article covers why that conversation is ahead of the evidence.

The abstract does not say, in either direction, and this page will not put a plateau claim in its mouth. What it publishes is the pair of timepoints per arm, and the subtraction is the published basis for the “still falling at 48 weeks” reading that circulates.

Two claims from widely shared videos are worth checking against the table. One describes liver fat being washed out of the liver within months: the published 24-week substudy is directionally consistent for the high-dose arms, which averaged reductions above 80%. Another repeats that nine out of ten participants with fatty liver returned to normal levels; the published figure is 86% of the 12 mg arm at 24 weeks, with lower proportions at lower doses. The habit to copy is the checking, since round numbers drift upward as they circulate.

The table has edges, and they are load-bearing: most of the questions people bring to a timeline article sit past them.

If the underlying goal is metabolic and weight management support, there are therapies a licensed clinician can prescribe today and a licensed US pharmacy can prepare today. Semaglutide and tirzepatide both have approved products behind them and an established prescribing route, and a clinician decides whether either is appropriate for your history.

Every dose PepScribe dispenses is compounded in the USA by licensed 503A pharmacies. No hidden overseas supply chain. The online visit is free, and you pay only if a clinician prescribes.