Retatrutide

From Retapedia, the free peptide encyclopedia
Medical disclaimer. This article is for informational purposes only and does not constitute medical advice. Consult a qualified clinician before considering any compound discussed below. See Retapedia : Medical disclaimer.

Summary

What it does
Retatrutide is used for weight loss: mid-stage trials recorded about 24 percent body-weight loss at 48 weeks, ahead of semaglutide and tirzepatide. The same trials also reported better blood sugar, lower blood pressure, and less fat in the liver.
How it works
A weekly injection under the skin that copies three hormones at once: GLP-1, GIP, and glucagon. Together they cut appetite and raise the energy the body burns. It is still in testing and has no approval.
WADA status
Prohibited by the World Anti-Doping Agency (WADA). Drug-tested athletes cannot use it.

Retatrutide (also known as Retatrutide or GIP/GLP-1/Glucagon triple agonist) is a performance-enhancing peptide studied for its effects on fat loss, weight loss, triple agonist. Triple receptor agonist (GLP-1/GIP/glucagon) with superior weight loss (24% in trials) vs tirzepatide/semaglutide. Phase 3 trials. Not FDA-approved.

Retatrutide (LY-3437943) is an investigational triple receptor agonist developed by Eli Lilly that simultaneously activates GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide), and glucagon receptors. This unique triple-agonist mechanism promotes superior weight loss compared to single or dual agonists by combining appetite suppression, enhanced insulin secretion, improved glucose homeostasis, and increased energy expenditure. Phase 2 trials demonstrated exceptional efficacy with 24.2% mean weight reduction at 48 weeks (12mg dose), significantly outperforming tirzepatide (~21%) and semaglutide (~15%).

Natty status
Retatrutide is classified as not natty. It is prohibited by WADA and most natural bodybuilding federations. Use places the athlete in the enhanced category. See § Natty status.
Contents [hide]
  1. 1 Overview
  2. 2 Mechanism of action
  3. 3 Reported effects
  4. 4 Dosage and administration
  5. 5 Natty status
  6. 6 Research
  7. 7 Related compounds
  8. 8 References
  9. 9 External links

Overview

Beyond weight loss, retatrutide shows promise for treating type 2 diabetes, metabolic-associated steatohepatitis (MASH/NAFLD), with 86% of patients achieving liver fat normalization at highest doses.

Currently advancing through Phase 3 TRIUMPH clinical trials (5,800+ participants) for obesity, obstructive sleep apnea, and knee osteoarthritis.

Not FDA-approved; investigational use only, and because it has no regulatory approval for human therapeutic use anywhere it is prohibited by WADA at all times under category S0 (non-approved substances).

Common side effects include dose-dependent gastrointestinal issues (nausea, vomiting, diarrhea) that typically diminish over time, plus modest heart rate increases (5-10 bpm).

Gradual dose titration over 12-16 weeks minimizes adverse events, with 16% discontinuation rate at highest dose versus 6% at lowest dose.

Mechanism of action

Triple agonist that curbs appetite and raises energy expenditure for 24% weight loss. Improves blood sugar, lowers blood pressure, and normalizes liver fat. Investigational; not FDA-approved.

Reported effects

Effects reported in the literature and from preclinical models include:

  • At the 12 mg maximal weekly dose, retatrutide reduced total body weight by 24.2% at 48 weeks, with 63% of participants losing at least 20% of body weight and a 23.2% reduction in fat mass. [2] Phase II
  • In patients with type 2 diabetes, retatrutide produced an absolute HbA1c reduction of 2.02%, with 27% of participants reaching normoglycemia below 5.7%. [2] Phase II
  • Retatrutide achieved an 82.4% relative reduction in hepatic fat and normalized liver fat in 86% of patients with metabolic dysfunction-associated steatotic liver disease. [2] Phase II
  • Pooled randomized controlled trial data show retatrutide lowers systolic blood pressure by 6.79 mmHg and diastolic blood pressure by 2.46 mmHg, and reduces total cholesterol, LDL-C, and triglycerides without changing HDL-C. [3] Phase II
  • In pooled randomized trials of adults with overweight or obesity and no diabetes, retatrutide produced 22.1% placebo-subtracted weight loss, and it ranked best for weight loss among 15 incretin-based therapies across 102 trials in type 2 diabetes. [5][4] Phase II
  • Retatrutide reduced body weight, alanine aminotransferase, hepatic triglycerides, cholesterol, and hepatic inflammatory markers in a diet-induced steatohepatitis mouse model. [1] Preclinical

Evidence grades: FDA approvedApproved (non-US)Phase IIIPhase IIPhase IPreclinicalAnecdotal

Dosage and administration

⚠
Dosage information is included for encyclopedic purposes only. Retapedia does not provide medical advice. See Retapedia : Medical disclaimer.

General

  • Phase 2 protocol - Week 1-4: 2mg once weekly (subcutaneous)
  • Phase 2 protocol - Week 5-8: 4mg once weekly
  • Phase 2 protocol - Week 9-12: 8mg once weekly
  • Phase 2 protocol - Week 13+: 12mg once weekly (maximum dose)
  • Lower starting dose (2mg vs 4mg) reduces GI side effects

Alternative titration

  • 1mg, then 2mg, then 4mg, then 6mg, then 8mg (escalate every 4 weeks)

Maintenance range

  • 4-12mg weekly depending on response and tolerability

Natty status

See also: Peptide § Natty status

Retatrutide is classified as not natty. It appears on the WADA prohibited list and is banned by major natural bodybuilding federations.[6] Use of this compound places the athlete in the enhanced category rather than the natural category in competitive contexts.

Research

12 active clinical trials on record — highest phase: Phase 3. 34 registered in total , of which 21 completed
View on ClinicalTrials.gov · fetched Sep 4, 2026

The peptide has been the subject of 30 studies and reference works collected on this site. Additional bibliography is in § External links below.

Other peptides in this catalogue with overlapping mechanisms or status:

MOTS-c Not natty
Mitochondrial-derived peptide that activates AMPK to improve insulin sensitivity and reproduce exercise-like metabolic adaptations in preclinical models. Investigational and WADA-banned; no approved human use.
Ozempic Natty
Reduces appetite and slows digestion for 15-21% weight loss. Improves blood sugar control. Lowers heart attack and stroke risk by 20%.
Tirzepatide Natty
Dual GIP/GLP-1 agonist. Reduces appetite for up to 21% weight loss. Improves blood sugar and diabetes control. First drug approved for obstructive sleep apnea. GI side effects common.
5-Amino-1MQ Not natty
Oral small-molecule NNMT inhibitor that raises NAD+ and S-adenosyl methionine to boost fat-cell energy expenditure. Studied only in rodents for fat loss; no human trials exist.

References

  1. ^ Steatohepatitis preclinical study
  2. a b c Triple Hormone Receptor Agonism: The Role of Retatrutide in Addressing Cardiovascular-Kidney-Metabolic (CKM) Syndrome: A Comprehensive Review.
  3. ^ Effect of Retatrutide, a Novel Triple Receptor Agonist, on Blood Pressure and Lipid Levels: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Recent review
  4. ^ Efficacy and safety of incretin-based therapies in patients with type 2 diabetes mellitus: a network meta-analysis based on clinical trials. Recent review
  5. ^ Efficacy and Safety of Glucagon-like Peptide-1 Receptor Agonists and Co-agonists for Weight Loss Among Adults Without Diabetes : An Updated Systematic Review. Recent review
  6. a b World Anti-Doping Agency. (2026). Prohibited List 2026.

External links

Categories: Peptides | Performance-enhancing substances | Fat loss | Weight loss | Triple agonist | Metabolic health

This page was last updated on September 4, 2026, at 13:21 (UTC).

Research last reviewed on September 4, 2026.

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