Retatrutide
1–12 mg · Weekly
Robert
Founder, F*CK Getting Old — independent researcher, not a medical professional.
Last reviewed · 2 cited sources
Evidence
- Human Studies
- 5
- Animal Studies
- 20
- Clinical Status
- Investigational
- Confidence
- Moderate
- Long-Term Safety
- Established short/medium-term in Phase 2/3 trials; long-term real-world data still accumulating
What this score is: a measure of how much research exists and how far along it is (animal-only vs. human trials, research-stage vs. FDA approved) — not how safe, effective, or worth trying a compound is. A low score usually means “early stage” or “understudied,” not “bad.” A high score doesn’t mean “better” for your goals than a lower-scored one.
This is not my personal rating of the compound, not a recommendation, and not medical advice. It’s a general research synthesis for informational purposes only, not a live literature count. See the linked research and talk to a licensed clinician before making decisions based on it.
Mechanism
Retatrutide is a triple agonist targeting GLP-1, GIP, and glucagon receptors, developed by Eli Lilly and studied in large pharmaceutical clinical trials for obesity and metabolic disease. It is the furthest along in formal human trials of any compound in this list, but was not FDA approved as of this writing — compounded/research versions are not the same as the eventual approved drug product.
Common Protocols
- Weekly subcutaneous injection, titrated up over weeks/months in published trials — self-directed dosing outside a trial or prescription carries real risk of getting this wrong
Side Effects
- GI side effects (nausea, diarrhea, constipation) were the most common in trials
- Trial data comes from a manufactured, quality-controlled product — research-grade/compounded versions carry additional, unstudied risk
Interactions
- Other GLP-1/GIP-class medications should not be combined without clinician guidance
Practical Details
- Cost
- $$$
- Typical Vial Size
- 10 mg
- Storage
- Refrigerate after reconstitution
Key Studies & Reviews
- Jastreboff AM et al. (2023). Triple-hormone-receptor agonist retatrutide for obesity — a phase 2 trial. N Engl J Med. PMID 37366315.
- Jastreboff AM et al. (2026). Retatrutide, a triple hormone receptor agonist, for treatment of obesity. N Engl J Med. PMID 42814954.
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Retatrutide FAQ
What is the typical Retatrutide dosage?
Commonly reported protocols: Weekly subcutaneous injection, titrated up over weeks/months in published trials — self-directed dosing outside a trial or prescription carries real risk of getting this wrong. Our reference entry uses 1–12 mg, Weekly. These reflect protocols reported in research and user communities, not a medical recommendation — dosing should be decided with a clinician.
What are the side effects of Retatrutide?
Reported side effects include: GI side effects (nausea, diarrhea, constipation) were the most common in trials; Trial data comes from a manufactured, quality-controlled product — research-grade/compounded versions carry additional, unstudied risk.
Is Retatrutide FDA approved?
Retatrutide is still being studied in clinical trials and is not FDA approved. Products sold outside those trials are not the same as a regulated drug.
How much research is there on Retatrutide?
Our evidence profile counts roughly 5 human and 20 animal studies, with moderate overall confidence. Long-term safety: Established short/medium-term in Phase 2/3 trials; long-term real-world data still accumulating.
Does Retatrutide interact with other drugs or supplements?
Other GLP-1/GIP-class medications should not be combined without clinician guidance.
How do I reconstitute Retatrutide?
A common setup is a 10 mg vial mixed with 2 mL of bacteriostatic water, which puts a 1–12 mg dose at about 20 units on a U-100 insulin syringe. Use the reconstitution calculator with your own vial and dose to get exact numbers. Storage: Refrigerate after reconstitution.
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GLP-1/GIP/Glucagon triple agonist