Compound profile

Retatrutide

GLP-1 / GIP / Glucagon

A triple-hormone-receptor agonist studied for its effects on body weight and metabolic markers, the furthest along of the newer “triple agonist” peptides.

Reviewed for accuracy · Last reviewed July 7, 2026
ClassGLP-1 / GIP / glucagon triple agonist
RouteSubcutaneous injection
Common research range2 – 12 mg, weekly
StorageRefrigerated, ~3–4 weeks once mixed

Overview

Retatrutide activates three separate metabolic receptors at once (GLP-1, GIP, and glucagon), which is why it's drawn so much attention in weight and metabolic research: the combination appears to affect appetite, energy expenditure, and blood sugar regulation simultaneously rather than through a single pathway.

It's administered as a once-weekly subcutaneous injection, typically starting at a low dose and titrating upward over several weeks to manage side effects.

Dosing

The published Phase 2 obesity trial escalated once-weekly subcutaneous doses through 1 mg, 4 mg, 8 mg, and 12 mg. Retatrutide is investigational, so there is no approved prescribing dose.

Read the full Retatrutide dosage guide →

Side effects

In that trial the most common adverse events were gastrointestinal (nausea, diarrhea, vomiting, constipation), generally mild to moderate and dose-related.

Read the full Retatrutide side effects guide →

Storage

Keep unmixed vials refrigerated and away from light. Once reconstituted, most research reports store it refrigerated for roughly 3–4 weeks. See the full storage & safety guide for handling and disposal basics.

FAQ

How is retatrutide different from tirzepatide?Retatrutide adds a third receptor target (glucagon) on top of the GLP-1/GIP combination tirzepatide uses, which is why it’s sometimes called a “triple agonist.”
Can I split a weekly dose into two smaller injections?Some people do to reduce injection-site reactions, but this changes the absorption profile. Discuss with a doctor before adjusting a protocol.
Does it need to be taken with food?No specific food requirement is typically noted; nausea is sometimes reduced by injecting in the evening or after a lighter meal.

References

  1. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 TrialNew England Journal of Medicine · 2023 · PMID 37366315 · DOI 10.1056/NEJMoa2301972
  2. A Phase 2 Study of Once-Weekly LY3437943 Compared With Placebo in Participants Who Have Obesity or Are Overweight With Weight-Related ComorbiditiesClinicalTrials.gov (sponsor: Eli Lilly and Company) · 2021 · NCT04881760
Running this protocol? PepHub can log your weekly doses and remind you.Download on the App Store

This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. Talk to a doctor before starting any compound.