Retatrutide is an investigational triple agonist of the GLP-1, GIP, and glucagon receptors, in late-phase clinical trials with the largest weight-loss results observed to date for an incretin therapy.
Retatrutide is an investigational triple agonist of the GLP-1, GIP, and glucagon receptors, in late-phase clinical trials with the largest weight-loss results observed to date for an incretin therapy. Mechanism: GLP-1 / GIP / Glucagon triple agonist. Typical route: Subcutaneous injection (weekly). FDA status: Not FDA-approved. In Phase 3 development by Eli Lilly. Compounded versions are not generally available because the molecule's manufacturing complexity and patent status limit pharmacy access.
Drug classGLP-1 / GIP / Glucagon triple agonist
Half-life~6 days
RouteSubcutaneous injection (weekly)
Phase 2 doses1, 4, 8, 12 mg/week
FDA statusInvestigational (Phase 3)
Compounded availabilityGenerally not available
Mechanism of action
Retatrutide simultaneously activates three receptors: GLP-1 (appetite suppression, insulin secretion), GIP (insulin sensitivity, lipid metabolism), and glucagon (increased energy expenditure, lipolysis). The triple mechanism is hypothesized to drive greater fat loss than dual GIP/GLP-1 agents like tirzepatide.
Dosing reference
Phase 2 trials used weekly subcutaneous injections at 1, 4, 8, and 12 mg dose levels. Maintenance dosing in development is not yet finalized; the manufacturer has not published a recommended regimen for clinical use.
Dosing information is provided for educational reference and is not medical advice. Patients should not initiate or modify any peptide regimen without consulting a licensed clinician. See our medical disclaimer.
FDA status & regulatory framework
Not FDA-approved. In Phase 3 development by Eli Lilly. Compounded versions are not generally available because the molecule's manufacturing complexity and patent status limit pharmacy access.
Editor's Pick · #1 of 10
NexLife — Semaglutide Program
Editor's PickPhysician-led503A pharmacyAll 50 states
Physician-led telehealth platform with Dr. Adam Kennah as Medical Director. Compounded semaglutide from an FDA-registered 503A pharmacy, all-inclusive pricing covering medication, supplies, and prescriber visits.
Trade-offs to know: Compounded medication, not FDA-approved Wegovy or Ozempic. Cash-pay only — not billable to insurance. Async telehealth model (no live video by default).
Editor's Pick · #1 of 10
NexLife — Tirzepatide Program
Editor's PickPhysician-led503A pharmacyAll 50 states
Physician-led tirzepatide program with the same compounding pharmacy, prescriber team, and clinical protocols as the semaglutide program. Methylcobalamin combined formulations available.
Trade-offs to know: Compounded medication, not FDA-approved Zepbound or Mounjaro. Cash-pay only. Tirzepatide is a newer compound with a shorter real-world safety record than semaglutide.
U.S. telehealth providers that work with Retatrutide
Phase 3 trials are ongoing as of 2026. The earliest realistic FDA-approval timeline is 2027-2028. Watch the Eli Lilly investor announcements for trial readouts and submission timing.
How much weight loss did retatrutide produce in trials?
In the Phase 2 trial published in 2023, the 12 mg dose produced approximately 24% body weight loss at 48 weeks — the largest reduction seen for any GLP-1-class agent to date. Phase 3 results may confirm or moderate this finding.
SS
Lead Medical Researcher
Dr. Sam Saberian
Doctor of Pharmacy; leads protocol research, peptide pharmacology, and provider evaluation.
AS
Medical Reviewer
Alen A. Schwartz, MD
Board-certified physician; reviews clinical accuracy of every published page.
JE
Edited by
Julliana Edwards
Editorial standards, factual accuracy, and corrections workflow.