Retatrutide
Retatrutide — the phase 2 trial schedule
Also called Reta, GLP-3, LY3437943, triple agonist
What the published phase 2 arms actually administered. Not approved, and not a label.
Combination evidence: Moderate
Where every number on this page comes from
Each quantity carries one of these five labels. They are not interchangeable, and the difference between the first and the last is the difference between a regulated finding and a rumour with a number attached.
- FDA labelling
- This figure appears in FDA-approved product labelling for an approved indication. It is the strongest warrant on this site.
- Published study arm
- This figure is the quantity administered in a named arm of the linked study. It describes what was studied, not what is advised.
- Clinical guideline
- This figure appears in published clinical or professional guidance.
- Manufacturer protocol
- This figure comes from a manufacturer or investigator document rather than from peer-reviewed literature.
- Community practice — no trial
- No clinical trial has tested this figure. It reflects what is commonly reported in practice and carries no evidentiary weight. It is shown because it is what circulates, and because showing it with this label is more useful than pretending it does not exist.
The figure most often reported for each compound. Where a compound has no separately sourced figure at this level, its most commonly reported figure is used instead, and the citation beneath it says so.
Duration
48 weeks
1 phase
Administrations
48
about 1/week at peak
Vials required
24
1 compound
Cost at this plan
$2,291.20
Peptira, list price
Phase by phase
Weeks 1–48 · 48 weeks
Randomised arms
Four arms were randomised, each reaching its target through a stepped escalation. The trial escalated within arms rather than fixing a quantity from week one.
Retatrutide
Once weekly, Sunday · Subcutaneous
Lowest sourced, per dose
1 mgPublished study arm
1 mg weekly · Phase 2, PMID 37366315 · in the study register
Most commonly reported, per dose
8 mgPublished study arm
8 mg weekly · Phase 2, PMID 37366315 · in the study register
Highest sourced, per dose
12 mgPublished study arm
12 mg weekly · Phase 2, PMID 37366315 · in the study register
Prepared at 20 mg in 2 mL
Every quantity above is one administration. At once weekly, sunday, that is 8.00 mg per week.
| Concentration | 10.00 mg/mL | Draw volume | 0.800 mL |
| Pull to (U-100) | 80.0 units | Doses per vial | 2 |
| This phase | 48 administrations | Vials, this phase | 24 |
Why it is here
Four randomised arms at 1, 4, 8, and 12 mg weekly over 48 weeks, with intermediate starting quantities in the higher arms.
What is not known
Phase 3 is ongoing. Phase 2 results do not establish the long-term safety profile, and the compound has no approved indication anywhere.
What you would need to buy
Vial counts are computed by simulating consumption, not by dividing total milligrams. Those two disagree whenever a vial cannot be finished, which is most of the time, and dividing under-buys.
| Compound | Vial | Administrations | Total material | Vials |
|---|---|---|---|---|
| RetatrutideRandomised arms | 20 mg | 48 | 384.00 mg | 24 |
| Total | 48 | 24 | ||
What it would cost
List prices from each vendor’s own product pages, with the date each figure was read. Quantity tiers are applied where a vendor publishes them.
Loti Labs
Prices as of 2026-08-24
$5,362.00
$15.96/day · $485.77/month
| RetatrutideReta 30mg (GLP-3) · 30 mg$11.05/mg listed · $13.81/mg after what expires unusedPriced at the 30 mg size rather than the 20 mg this plan assumes, because across the sizes this vendor stocks it works out cheapest for the whole course. Vial count re-simulated at that strength. | 16 × $331.49 | $5,303.84 |
| Bacteriostatic water10ML Reconstitution Solution · 10 mLThis plan uses 32.0 mL across every reconstitution. 8.0 mL is left over, because bottles do not divide. | 4 × $14.54 | $58.16 |
| Syringes48 administrations, so 48 syringes. None of the vendors priced on this site sells syringes, alcohol pads or a sharps container. They are ordinary pharmacy items in most places and restricted in some. The count below is what the plan requires; where to obtain them is outside what this site can tell you. | 48 × — | Not sold here |
| Total, compounds and water | $5,362.00 | |
Above this vendor's published $99 free-shipping threshold.
We earn nothing from this link. Loti Labs has no affiliate programme.
Pure Health Peptides
Prices as of —
Cannot supply this plan
| RetatrutidePure Health Peptides's largest listing for this compound is 5 mg, and this plan administers up to 8 mg at once. One vial cannot deliver a single administration. Drawing each dose from two vials is possible, but it changes the syringe pull and doubles the reconstitution, so it is a different plan and is not priced here. | — | — |
| Syringes48 administrations, so 48 syringes. None of the vendors priced on this site sells syringes, alcohol pads or a sharps container. They are ordinary pharmacy items in most places and restricted in some. The count below is what the plan requires; where to obtain them is outside what this site can tell you. | 48 × — | Not sold here |
| Total, compounds and water | $0.00 | |
$175.00 below the published $175 free-shipping threshold.
This total is not comparable. Pure Health Peptides cannot supply Retatrutide, so the figure above covers a smaller basket than the other columns.
We earn nothing from this link. No affiliate programme was found for this vendor.
Peptira
Prices as of 2026-08-25
$2,348.20
$6.99/day · $212.74/month
| RetatrutideRETA-3 | 30MG · 30 mg$4.77/mg listed · $5.97/mg after what expires unusedIdentity inferred. This vendor sells it as “RETA-3 | 30MG” and does not write the compound name anywhere on the page. The mapping is ours, not theirs.Priced at the 30 mg size rather than the 20 mg this plan assumes, because across the sizes this vendor stocks it works out cheapest for the whole course. Vial count re-simulated at that strength. | 16 × $143.20 | $2,291.20 |
| Bacteriostatic waterBAC Water 10ML · 10 mLThis plan uses 32.0 mL across every reconstitution. 8.0 mL is left over, because bottles do not divide. | 4 × $14.25 | $57.00 |
| Syringes48 administrations, so 48 syringes. None of the vendors priced on this site sells syringes, alcohol pads or a sharps container. They are ordinary pharmacy items in most places and restricted in some. The count below is what the plan requires; where to obtain them is outside what this site can tell you. | 48 × — | Not sold here |
| Total, compounds and water | $2,348.20 | |
Above this vendor's published $250 free-shipping threshold.
Peptira runs an affiliate programme. This site has not applied to it, so no commission is earned on this link today.
List price is not the price anyone pays
What usually goes wrong
Ranked by how often it happens rather than by how serious it sounds.
Treating an investigational compound as an approved one
Retatrutide has completed phase 2. It is not approved, it is not legally compoundable, and material sold as research-use-only is not the trial product.
Starting at a target quantity
Every arm escalated. Reproducing the endpoint quantity without the ramp is not what was studied.
What is worth measuring
Markers that would actually tell you something, and what each one tells you. Nothing here is a requirement, and none of it substitutes for a clinician who knows your history.
| Marker | When | What it tells you |
|---|---|---|
| Heart rate | Ongoing | Dose-dependent heart-rate increase was reported in phase 2. |
| Gastrointestinal tolerance | Through escalation | The dominant adverse-event category in this class. |
Populations this was not studied in
An absence of evidence in a group is not evidence of safety in that group. These are listed because the gap itself is the finding.
- Anyone outside the trial's enrolment criteria
- Pregnancy
- Type 1 diabetes
Related protocols
Semaglutide
The 16-week step-up written into the approved label, with the arithmetic done for each step.
Tirzepatide
Labelled 2.5 mg steps to a 5, 10, or 15 mg maintenance, with 176-week follow-up behind it.
Tesamorelin
2 mg daily, from an approved label, with a 52-week pooled analysis behind it.
Protocol last reviewed 2026-08-24. Every quantity on this page carries its own source. If you find one that does not, that is a bug and the build should have caught it.