Retatrutide is an investigational triple agonist acting at the GIP, GLP-1 and glucagon receptors. Trials administer it subcutaneously once weekly. Published Phase 2 data describe the largest mean body-weight reductions reported for an incretin-class agent to date. It is not approved by any regulator, for any use, anywhere.
By Tessaro Pty Ltd, the maker of Pepti · Last reviewed
This page is a reference, not a protocol. It sets out what the published trials actually report, what the compound's half-life means for a weekly record, and what a clean log holds. It contains no dose figures and no schedule, and the section further down explains why that is deliberate rather than an omission.
| Property | Value |
|---|---|
| Mechanism | Triple agonist — GIP, GLP-1 and glucagon receptors |
| Development status | Investigational; Phase 3 studies listed as ongoing in public trial registries |
| Trial route | Subcutaneous injection |
| Trial cadence | Once weekly |
| Half-life | Approximately 6 days (about 144 hours) — per published pharmacokinetics (Jastreboff et al., NEJM 2023) |
| Regulatory status | Not approved in any jurisdiction, for any indication |
Published data describe a mean body-weight reduction of 24.2 percent at 48 weeks in the Phase 2 trial, and report that 100 percent of participants in the two highest dose groups reached a reduction of at least 5 percent (Jastreboff et al., NEJM 2023). That first figure is the reason the compound draws the attention it does: it is the largest mean reduction published for an agent in this class.
Trials report 14.9 percent mean body-weight reduction at 68 weeks for semaglutide (Wilding et al., NEJM 2021), and 20.9 percent at 72 weeks for tirzepatide (Jastreboff et al., NEJM 2022). Those two figures are the context that makes the retatrutide number legible — without them, 24.2 percent is a number without a scale.
The comparison has real limits and they are worth stating plainly. These are three separate trials, run in different populations, over different durations, with different designs and endpoints. Lining the percentages up in a row is a convenience, not a head-to-head result, and no trial has compared these agents directly at the time of writing. Published data also describe adverse effects concentrated in the gastrointestinal system, and a Phase 2 result is not a Phase 3 result: the larger and longer studies that determine whether an agent is approved are still running.
Published pharmacokinetics describe a half-life of approximately 6 days, about 144 hours (Jastreboff et al., NEJM 2023). A half-life is the time taken for half of what is present to clear, and at roughly six days the practical consequence is that weekly injections overlap heavily instead of clearing between them. Levels build across the early weeks rather than returning to zero, which is why trial designs settle on a weekly rhythm in the first place.
Two things follow for record-keeping. A missed week is a much larger gap than a missed day would be on a daily compound, so the log needs to make an absent week obvious at a glance rather than burying it. And because the curve is slow, effects and side effects observed in any given week are a product of several preceding weeks, not just the most recent injection — which makes the dated history far more informative than any single entry in it.
Retatrutide is investigational. There is no approved label anywhere in the world, which means there is no authorised dosing, no approved titration path, and no clinician-facing guidance outside trial protocols. Any figure published as a “typical dose” for an unapproved compound is not drawn from an approved source, because no such source exists. It is drawn from forum consensus, from vendor copy, or from someone's reading of a trial protocol that was run under monitoring conditions that do not apply outside it.
Pepti is a measurement and record-keeping tool. It converts a figure you already have into a draw volume and syringe units, tracks what is left in each vial, and remembers where the last injection went. It does not supply the figure, and it will not, for this compound or any other. Pages that publish dose tables for investigational compounds are publishing folklore with the typography of evidence — the numbers look authoritative because they are set in a table, not because anything stands behind them. The figure belongs to you and whoever directs your use. The arithmetic is what we are for.
Because the cadence is weekly, there are relatively few entries in a retatrutide log, which makes each one carry more weight. A record worth keeping holds the following.
The record-keeping method in full is set out in tracking a retatrutide schedule, and the reconstitution calculator converts the figures you already have into a draw volume and a count of doses per vial.
Retatrutide is an investigational peptide that acts as a triple agonist at three receptors at once: GIP, GLP-1 and glucagon. The first two are shared with earlier incretin-class agents; the glucagon receptor is the addition that distinguishes it. It has been studied as a once-weekly subcutaneous injection in clinical trials.
No. Retatrutide is not approved by any regulator, in any country, for any indication. Public trial registries list Phase 3 studies as ongoing. Because it is unapproved there is no label, no authorised dosing, and no clinician-facing guidance for it outside trial protocols.
Retatrutide's half-life is approximately 6 days (about 144 hours), per published pharmacokinetics (Jastreboff et al., NEJM 2023). That is the reason a weekly cadence appears in trial designs: successive weekly injections overlap substantially rather than clearing between administrations.
Tirzepatide is a dual agonist acting at GIP and GLP-1 receptors. Retatrutide adds a third target, the glucagon receptor. Trials report a mean body-weight reduction of 20.9 percent at 72 weeks for tirzepatide (Jastreboff et al., NEJM 2022) and 24.2 percent at 48 weeks for retatrutide (Jastreboff et al., NEJM 2023). These come from separate trials with different populations, durations and designs, so the figures are not a head-to-head comparison.
It depends entirely on the form. Trial product is supplied as a solution, already in liquid form and requiring no mixing. Material circulating outside trials is commonly supplied as a lyophilized powder, which is inert until a diluent is added. These are two different physical products, and a record that does not say which one it describes is ambiguous later.
No. Pepti supplies no dose figures for retatrutide or for anything else. It records the figure you already have from whoever directs your use, converts it into a draw volume and syringe units, tracks what is left in each vial, and keeps the site sequence. The arithmetic is ours; the figure is not.
This page is a reference on published evidence and record-keeping. It does not recommend retatrutide or any other substance, and it provides no dose figure, no titration amount, and no schedule. Retatrutide is investigational and not approved for any use.
The Pepti peptide tracker for iPhone keeps the weekly log, the site sequence, the vial count and the weight trend in one place.
Not medical advice. Pepti is a record-keeping and measurement tool, not a medical device.
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