Retatrutide (LY3437943) — Investigational Compound

What it is and what it treats

Retatrutide (development code LY3437943) is an investigational synthetic peptide being studied by Eli Lilly as a triple agonist acting on the GIP, GLP-1 and glucagon receptors. It is under clinical investigation for potential use in obesity, overweight with associated conditions, and related metabolic disorders. It has not received marketing authorisation from the FDA, EMA or any other national medicines regulator, and no approved therapeutic indication currently exists.

Published data from registered clinical trials, including a Phase 2 study (ClinicalTrials.gov identifier NCT04881706), describe investigation of retatrutide across a range of subcutaneous doses in study participants, with outcomes reported in peer-reviewed literature. These are research findings from controlled trials and do not represent an approved label, an authorised dose, or a basis for clinical prescribing.

This monograph is provided strictly as a research and scientific reference summary. Retatrutide is not available for clinical prescribing, is not authorised for human therapeutic use in any jurisdiction, and material referencing its properties should be understood in the context of ongoing investigational drug development, not an approved medicine.

Presentations and dosage forms

• Investigational lyophilised peptide formulations used in registered clinical trials
• Not available as an approved pharmaceutical product in any dosage form
• Any formulation, strength or presentation described in trial literature relates strictly to the controlled research setting of registered studies

How it is administered

Because retatrutide is not an approved medicine, there is no approved route of administration, dose or treatment schedule for clinical or therapeutic use. Published trial protocols describe subcutaneous administration at defined intervals within the controlled setting of registered clinical trials, using dose titration schedules specific to each study protocol.

Any dosing information appearing in scientific literature relates exclusively to investigational use under institutional review board or ethics committee oversight, informed consent, and a registered clinical trial protocol. It cannot be extrapolated to unsupervised or non-trial use and is not a treatment recommendation of any kind.

Individuals and organisations engaging with retatrutide should do so only within the framework of properly authorised, ethics-approved clinical research, in compliance with applicable national laws governing investigational medicinal products.

Storage and handling

• Investigational peptide material used in registered trials is typically stored under refrigerated or frozen conditions specified by the study sponsor's chemistry, manufacturing and controls documentation
• Storage conditions for investigational compounds are dictated by trial-specific protocols and are not published as a general consumer storage guideline
• Material of this kind should be handled only within a licensed research facility operating under appropriate ethics and regulatory oversight

Side effects

Because retatrutide has no approved product label, there is no authorised adverse reaction listing. The following reflects safety observations reported in published Phase 1 and Phase 2 clinical trial literature and is provided for research and scientific context only, not as clinical guidance.

Commonly reported

Serious effects requiring medical attention

As retatrutide remains investigational, its full safety profile has not been established through completed regulatory review. Any use outside a registered, ethics-approved clinical trial carries unquantified risk, and no safety monitoring pathway exists outside such a trial framework.

Availability and supply route

Retatrutide is not registered or authorised for sale or clinical use by any national medicines regulator. There is no country in which it holds a marketing authorisation for human therapeutic use, and it should not be sourced, supplied or administered outside a registered clinical trial.

Access to retatrutide occurs solely through enrolment in registered clinical trials conducted under sponsor oversight, ethics committee approval and informed consent, consistent with Good Clinical Practice standards. There is no named-patient or compassionate-supply pathway for this compound, as it has not reached a stage of regulatory evaluation that would support such access.

Pharmacy Remedy is a licensed Turkish pharmaceutical wholesaler operating in the B2B channel for authorised, registered medicines supplied against valid prescriptions to licensed healthcare entities; it does not supply investigational compounds such as retatrutide for clinical or therapeutic use, and does not sell any product to members of the public.

Frequently asked questions

Primary sources

• ClinicalTrials.gov — Retatrutide (LY3437943) Phase 2 study, NCT04881706
• ClinicalTrials.gov — Retatrutide Phase 3 (TRIUMPH programme) listings

Further reading and regulatory routes

• How to verify a medicine is genuine
• Why medicines cost less in Türkiye
• WHO falsified medicine alerts
• Named patient supply
• UAE import guide
• For healthcare professionals
• All medicine monographs

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