Retatrutide: Frequently Asked Questions

Retatrutide, development code LY3437943, is an investigational molecule developed by Eli Lilly and Company. Its developer describes it as a single molecule that activates three hormone receptors — GIP, GLP-1 and glucagon — which is why it is called a triple hormone receptor agonist. In clinical trials it is given as a once-weekly subcutaneous injection.

Full scientific overview →

It is the internal development code Eli Lilly assigned before the molecule received its generic name. Both refer to the same substance. The code is how retatrutide appears in the earlier trial records, including the 2019 first-in-human study.

It is not a steroid. GLP-1 receptor agonism is one of its three actions, so it belongs to the broader incretin-based family — but calling it simply a GLP-1 drug is incomplete, because it also targets the GIP and glucagon receptors.

How the three pathways work →

We could not locate an authoritative public source establishing its molecular formula, molecular weight, sequence or formulation. Detailed pharmaceutical specifications are submitted to regulators as commercially confidential material and typically become public only on approval. Rather than repeat unsourced figures found elsewhere, we state that they are not publicly established. Ingredient profile →

No. As of 24 October 2026 it has no marketing approval from the FDA or any other regulator worldwide. Eli Lilly said on 23 July 2026 that it was completing the manufacturing (CMC) data package and planned to submit a Biologics License Application in Q1 2027. A plan to file is not an approval, and the plan can change.

No marketing approval in India could be located in any primary regulatory record. India does host authorised clinical trial sites — we verified Indian sites in five retatrutide studies, including TRIUMPH-1, TRIUMPH-2 and TRIUMPH-Outcomes.

Those are different regulatory acts. A trial authorisation permits research under an approved protocol; a marketing approval permits sale. Only the second makes a medicine available. Full India page →

No UAE registration could be located in a primary regulatory record. Separately, we checked the location data of all 33 registered retatrutide studies and found no study site in the UAE — the only West Asian locations in the whole programme are in Israel and Türkiye.

We report that as what our search found, not as a legal determination. Verify current status with MoHAP and the Emirates Drug Establishment. Full UAE page →

Not lawfully, and there is no genuine price. Eli Lilly has stated the position directly:

Retatrutide is an investigational molecule that cannot be legally sold or marketed for human use. Eli Lilly, 23 July 2026

Because no product is approved anywhere, there is no regulated supply chain and no legitimate retail price. Material advertised online — including items labelled “research use only” — has not been assessed by any regulator; its identity, purity and contents are unverified, and a seller-supplied certificate of analysis is not independent verification. This site does not sell, source or broker any product.

No date exists and we will not estimate one. Eli Lilly has announced a plan to file in the United States in Q1 2027; we located no equivalent announcement for India or the UAE. Filing is not approval, each regulator reviews on its own timeline, and a decision in one country does not determine another. Anyone publishing a launch date for these markets is speculating.

We are not affiliated with any trial, cannot refer anyone to a site, and cannot assist with enrolment. Many retatrutide trials are completed or closed to recruitment. If you want to explore trial participation, search ClinicalTrials.gov (or CTRI for India), read the eligibility criteria, and discuss it with your own doctor.

Under the efficacy estimand, mean body-weight reduction at the highest dose was:

• 28.3% at 80 weeks — TRIUMPH-1, obesity without diabetes (placebo −2.2%)
• 20.8% at 80 weeks — TRIUMPH-2, with type 2 diabetes (placebo −4.0%)
• 22.6% at 80 weeks — TRIUMPH-3, severe obesity with CVD (placebo −3.2%)
• 28.7% at 68 weeks — TRIUMPH-4, with knee osteoarthritis (placebo −2.1%)

Populations, baselines and durations differ, so these are not interchangeable and should not be ranked against each other. Full results →

Usually because of the estimand — the definition of what a number represents, particularly how it handles people who stopped treatment.

TRIUMPH-1 at 12 mg is 28.3% under the efficacy estimand (the effect had participants stayed on treatment) and 25.0% under the treatment-regimen estimand (everyone randomised, regardless). Press releases led with the first; the NEJM abstract reports the second. Neither is wrong. The full explanation →

No published evidence answers this. Mounjaro is a brand of tirzepatide; Ozempic and Wegovy are brands of semaglutide. There is no published head-to-head trial of retatrutide against either in obesity.

TRIUMPH-5 is comparing retatrutide with tirzepatide directly in about 800 adults and had not reported as of 24 October 2026. Comparing percentages across separate trials is unreliable, because populations, baselines, durations and estimands all differ. vs tirzepatide → · vs semaglutide →

No such conclusion is available. TRIUMPH-3 reported cardiovascular event analyses, but every confidence interval crossed 1.0 and event counts were small, in a trial powered for weight change rather than cardiovascular outcomes. Those data establish neither benefit nor harm. The trial designed to answer the question is TRIUMPH-Outcomes, due February 2029. The analysis in full →

Predominantly gastrointestinal: nausea, diarrhoea, constipation and vomiting, plus decreased appetite. In TRIUMPH-1 at 12 mg, nausea was reported in 42.4% against 14.8% on placebo.

Dysesthesia — altered or unpleasant sensation — was reported consistently and rose with dose, reaching 20.9% at 12 mg in TRIUMPH-4 against 0.7% on placebo. Eli Lilly described these events as generally mild to moderate, mostly resolving during treatment. Every reported figure →

That cannot be answered yet. Trials reported adverse events broadly consistent with other incretin-based therapies, but safety observed in a trial is not the same as safety in general: participants were screened, supervised and monitored; the longest reported exposure is 104 weeks; and no regulator has reviewed the complete safety package. Safety evidence and its limits →

No cancer finding appears in any primary source we located, and cancer does not appear among reported common adverse events — but that is an absence of reported evidence, not a demonstration of safety, and cancer risk is assessed over far longer periods. Hair loss does not appear among the most common reported events, and we could not locate incidence data. We could not locate sex-stratified adverse-event data at all. More on what the evidence cannot answer →

This site publishes no dosing guidance, dose calculators, titration schedules, reconstitution guides or injection instructions, and will not.

What we do report is trial design: Phase 3 trials studied 4 mg, 9 mg and 12 mg once weekly, reached by stepwise escalation from 2 mg with increases every four weeks. That is a fact about how the research was conducted.

It is not transferable guidance. In a trial, every step comes with eligibility screening, scheduled clinical assessment, laboratory monitoring, pre-defined rules for pausing or reducing dose, and investigators who can intervene. The schedule is not the intervention — the supervision around it is inseparable from it. How trials are designed →