COMPARE THE EVIDENCE

Retatrutide

Findings, possible implications, and reported experiences.

About Retatrutide

PeptideMetabolism

Primary research area: Metabolism · obesity
Regulatory status: Investigational
Evidence level: Human trials
Primary mechanism: GIP, GLP-1 and glucagon receptor agonist

Reference profile available · Coverage varies by section

Also known as LY3437943

Retatrutide (LY3437943) is a peptide that activates GIP, GLP-1 and glucagon receptors. It is studied for effects on blood glucose and body weight. [1]

What has been observed?

Selected source-linked reading notes, not the complete literature or a pooled conclusion.

Human · Sponsor report

What do the newer phase 3 results add?

80 weeks; 12 mg; efficacy analysis; sponsor topline report. Treatment-regimen estimate: 25.0%.

Lilly reported 28.3% average weight reduction at 80 weeks for 12 mg using the efficacy analysis; the treatment-regimen analysis reported 25.0%.

Limits: Sponsor-reported topline results. Different analysis assumptions produce different estimates; this was not a direct tirzepatide comparison.

Open primary source · Read interpretation separately

Human · Reading scope not recorded

How strong is the weight-loss signal for retatrutide?

48 weeks; highest-dose group, 12 mg; randomized phase 2 trial, 338 adults.

The highest-dose group lost an average of 24.2% of body weight at 48 weeks, versus 2.1% with placebo.

Limits: This is a separate trial from SURMOUNT-5. Its percentages cannot establish superiority to tirzepatide or semaglutide. Gastrointestinal events and heart-rate increases were reported.

Open primary source · Read interpretation separately

Explore outcomes for this compound

Uses & research: The cited phase 1b trial investigated safety, glucose control and weight in people with type 2 diabetes; a phase 2 trial studied adults with obesity. [1][2]
Known half-life: Approximately 6 days in the phase 1b study after administration under the skin. [1]
Half-life describes how quickly the measured drug concentration falls by half. It does not set a dosing interval.
Evidence & important limits: These are investigational trial results, not a treatment recommendation. Gastrointestinal adverse effects were common in the trials. Comparisons across different trials cannot establish a universal best compound. [1][2]

Safety & evidence boundaries

Source-specific information, not a personal safety clearance or monitoring plan.

These are investigational trial results, not a treatment recommendation. Gastrointestinal adverse effects were common in the trials. Comparisons across different trials cannot establish a universal best compound.

Urva et al., LY3437943 phase 1b trial (2022)Jastreboff et al., retatrutide obesity trial (2023)

Explore safety questions by system

These are literature filters, not claims that this compound causes each effect. A keyword match is not a confirmed adverse reaction.

Heart, blood pressure & lipids Liver injury Kidney function Glucose effects Reproductive & endocrine effects Mood & sleep Adverse effects & interactions

Interactions, rare harms, long-term effects and reversibility require separate evidence. Do not infer they are absent when the sources here do not address them.

Identity, names & formulations

Canonical compound: Retatrutide · retatrutide

Searchable names: LY3437943

Names share a parent research page. Different esters, salts, routes and brands are not assumed to have the same half-life, indication or exposure.

Combination evidence stays attached to the studied combination. It is not automatically assigned to each ingredient.

Understand the evidence types

Read the model and design first, then the population, outcome and limitations. These categories describe evidence, not a best-compound ranking.

Randomized human trials: Compare assigned interventions. Randomization does not by itself establish low bias or relevance to every population.
Controlled human studies: Use a comparison group; allocation and confounding still matter.
Prospective human research: Follows participants forward. It may be observational or interventional, so this is not a separate quality grade.
Observational human research: Describes associations. Confounding can explain differences.
Case reports and series: Useful for unusual events and safety signals, not reliable rates or effect sizes.
Animal research: Can test biology and function in a living model. Human exposure, benefit and safety remain separate questions.
Cell and tissue research: Tests responses in a preparation, including human-derived cells. It is not a human participant trial.
Mechanistic and computational evidence: Helps explain or predict a pathway; predictions need experimental and clinical testing.
Anecdotal reports: Self-reported experiences can generate questions. Product identity, selection bias and other interventions may be uncontrolled.

Systematic reviews synthesize studies and depend on their quality. Preprint status and abstract versus full-paper reading are separate labels. Citation popularity measures attention, not reliability. A study summary is not a formal quality appraisal.

Sources for this profile

1. Urva et al., LY3437943 phase 1b trial (2022) Study abstract · people with type 2 diabetes
2. Jastreboff et al., retatrutide obesity trial (2023) Study abstract · adults with obesity

Reference facts checked 2026-09-16. Source scope is listed above; this is not a formal quality appraisal. See each label for full prescribing information.

Browse all studies

Research outcomeResearch model

Study model describes the source. Confidence depends on methods, replication, population and outcome.

Loading compound research…