WhatPeptide

Retatrutide

An investigational triple agonist (GLP-1/GIP/glucagon) with large early-stage weight-loss signals in phase 2 studies.

Preliminary evidence Investigational GLP-1/GIP/Glucagon Agonist

Written by WhatPeptide Editorial Team · Last updated 2026-03-17

Currently in clinical trials — not yet approved for any indication.

Half-life

Approximately 6 days (phase 2 data)

Dosage range

Investigational titration protocols; no approved range

Administration

Subcutaneous injection

Research level

Preliminary

How Retatrutide works

Retatrutide targets GLP-1, GIP, and glucagon receptors, combining appetite suppression with increased energy expenditure signaling. Early human trials demonstrate substantial dose-dependent body-weight effects but with notable gastrointestinal adverse events. Long-term cardiovascular and safety outcomes remain under study.

Also known as: LY3437943, Triple agonist

Clinical trial efficacy

Phase 2: -24.2% body weight at 12 mg dose over 48 weeks, the largest weight reduction reported for any single agent at the phase 2 level.

Research relevance

Fat Loss
Strong research relevance 95
Muscle Growth
Some relevance 30
Anti-Aging & Longevity
Some relevance 25
Recovery & Healing
Some relevance 20
Sleep & Relaxation
Some relevance 20
Sexual Health
Some relevance 20

Side effects & safety

Nausea Vomiting Diarrhea Appetite suppression Pancreatitis (rare but serious) Thyroid C-cell tumors (class-based preclinical signal — rodent data, human relevance uncertain) Potential lean mass loss alongside fat loss

Contraindications

Pregnancy
History of severe pancreatitis
Thyroid cancer risk factors

Consult a healthcare provider before use if any of these apply to you.

Key studies

FAQ

What is Retatrutide? +
An investigational triple agonist (GLP-1/GIP/glucagon) with large early-stage weight-loss signals in phase 2 studies. Its mechanism of action is based on preliminary or early-stage research.
What is Retatrutide researched for? +
Retatrutide has the strongest research relevance for Fat Loss, Muscle Growth, Anti-Aging & Longevity. Evidence is based on preliminary or early-stage research.
What are the side effects of Retatrutide? +
Reported side effects include Nausea, Vomiting, Diarrhea, Appetite suppression, Pancreatitis (rare but serious), Thyroid C-cell tumors (class-based preclinical signal — rodent data, human relevance uncertain), Potential lean mass loss alongside fat loss. Key contraindications: Pregnancy; History of severe pancreatitis; Thyroid cancer risk factors.
Is Retatrutide FDA approved? +
Retatrutide is currently in clinical trials and is not yet approved by the FDA.
How is Retatrutide administered? +
Retatrutide is typically administered via subcutaneous route. Researched dosage range: Investigational titration protocols; no approved range. Half-life: Approximately 6 days (phase 2 data).

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