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.Learn more →

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.