Is Retatrutide considered natty?

Retatrutide is generally regarded as compatible with natural bodybuilding. Most sanctioning bodies do not prohibit its therapeutic use, though rules vary by federation.

Is Retatrutide on the WADA prohibited list?

As of the current prohibited list, Retatrutide is not explicitly banned by WADA, though regulations can change. Always verify against the current year's WADA prohibited list before competition.

How is Retatrutide administered?

Retatrutide is typically administered via: subcutaneous injection. Dosage and administration protocols vary; see the Dosage section for details.

Retatrutide - Retapedia | Natty or Not?

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.

Retatrutide
Structure of Retatrutide. 39-aa GLP-1/GIP/glucagon triagonist with Aib substitutions, γGlu–C20 diacid lipidation, and a C-terminal amide. Source: Wikimedia Commons.
Identification
Class	Modified peptide
PubChem CID	171390338
Other names	Retatrutide · GIP/GLP-1/Glucagon triple agonist
Trade names	Retatrutide
Administration
Routes	Subcutaneous injection
Status
Verdict	Natty
WADA	Not prohibited^[6]
Article meta
Slug	`retatrutide`
Last edited	June 3, 2026
Tags	fat loss, weight loss, triple agonist, metabolic health, diabetes, subcutaneous

Retatrutide (also known as Retatrutide or GIP/GLP-1/Glucagon triple agonist) is a therapeutically researched 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 generally regarded as compatible with natural bodybuilding, though competitive federations may differ. See § Natty status.

Contents [hide]

1 Overview
2 Mechanism of action
3 Reported effects
4 Dosage and administration
5 Natty status
6 Research
7 Related compounds
8 References
9 External links

Overview

Beyond weight loss, retatrutide shows promise for treating type 2 diabetes, metabolic-associated steatohepatitis (MASH/NAFLD), with 90% 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.

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

Reduces appetite and boosts metabolism for 24% weight loss. Improves blood sugar, lowers cholesterol, normalizes liver fat in 90% of users.

Reported effects

Effects reported in the literature and from preclinical models include:

At the 12mg maximal weekly dose, retatrutide produced a 24.2% reduction in total body weight at 48 weeks in Phase 2 data, with 63% of participants achieving at least 20% body weight loss and a 23.2% reduction in fat mass. ^[3]^[4] Phase II
In patients with type 2 diabetes, retatrutide achieved an absolute HbA1c reduction of 2.02%, with 27% of participants reaching normoglycemia (HbA1c below 5.7%). ^[3] Phase II
Retatrutide achieved an 82.4% relative reduction in hepatic fat and normalization of liver fat in 86% of patients, with early clinical data indicating potent hepatoprotective effects in metabolic dysfunction-associated steatotic liver disease. ^[3]^[5] Phase II
Retatrutide produced systemic hemodynamic unloading, including an 8.79 mmHg reduction in systolic blood pressure and significant attenuation of the urine albumin-to-creatinine ratio. ^[3] Phase II
Retatrutide intervention over two weeks significantly reduced body weight, ALT levels, hepatic triglycerides and cholesterol, and hepatic inflammatory markers in a 31-day diet-induced steatohepatitis mouse model. ^[2] Preclinical
The Phase 3 TRIUMPH program is evaluating weekly subcutaneous retatrutide for obesity, obstructive sleep apnea, and knee osteoarthritis across over 5,800 participants using a basket trial design. ^[1] Phase III

Evidence grades: FDA approved Phase III Phase II Phase I Preclinical Anecdotal

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 generally regarded as compatible with the natty designation, particularly when used for therapeutic healing purposes. Opinions vary across natural bodybuilding federations, and athletes who compete should consult the rulebook of their respective sanctioning body.^[6]