On this page
What it is
An investigational single molecule designed to activate three receptors — GIP, GLP-1 and glucagon.
How it is proposed to work
Adding glucagon receptor agonism is proposed to increase energy expenditure on top of the appetite and glycaemic effects of incretin agonism. This mechanism also underlies several of its open safety questions.
Approved medical uses
None. Retatrutide has no approved human medical indication in the jurisdictions we track. Any use is outside an approved label.
Human research
Each entry states what the study found and, separately, what it cannot show.
- Randomised controlled trial2023n = 338
Phase 2 randomised trial in adults with obesity
Finding. Dose-dependent weight reduction over 48 weeks, larger on average than reported for approved incretin therapies.
Limitation. Phase 2, single programme, no long-term outcome data, and no head-to-head phase 3 comparison. Phase 2 effect sizes frequently shrink in phase 3.
Preclinical research
Animal and laboratory work. Useful for generating hypotheses; it cannot establish that something works in people.
No preclinical studies catalogued.
Potential safety concerns
- WatchPreliminary
Dose-dependent gastrointestinal effects and heart-rate increases have been reported. Long-term significance is unknown.
- SeriousEstablished
Because it is unapproved, material sold to consumers has no verified identity, purity, sterility or dosing accuracy. This is a documented source of harm independent of the molecule itself.
Known interactions and contraindication considerations
- Not characterised in humans outside trial settings.
This list is not exhaustive and is not a substitute for a clinician reviewing your full medication history.
Regulatory status
Status is shown per jurisdiction and is accurate only as of the date stated. Where a compound is approved, the approval is bound to a specific formulation, manufacturer and indication — shown in the detail column.
| Jurisdiction | Standing | Detail |
|---|---|---|
United States FDA | Unapproved / investigational as of 1 Jun 2026 | Investigational. Not approved for any indication. Any product sold outside a clinical trial is unapproved. |
European Union EMA | Unapproved / investigational as of 1 Jun 2026 | Investigational; no marketing authorisation. |
India CDSCO | Unapproved / investigational as of 1 Jun 2026 | A first-time synthetically manufactured peptide is treated under the new-drug pathway. Central Licensing Authority permission is required before import or manufacture for sale or distribution. |
How it is being used
What the grey community actually runs, the reasoning they give, and our read on whether it follows from known biology. This is observation, not evidence, and not a recommendation.
Weight loss, ahead of any approval
What is run
Self-directed titration using grey-sourced material, following patterns inferred from published phase 2 trial designs.
Their mechanistic reasoning
That triple agonism adds glucagon-receptor-driven energy expenditure on top of incretin appetite effects, and that the published phase 2 weight reductions justify not waiting for approval.
Reported in the community’s own terms. Not our position.
Stacked with
- Resistance training and protein—Lean-mass protection matters more here, since reported effect sizes are larger.
Regimen shape
- Dose
- figure withheld
- Scale
- Inferred from published trial arms
- Route
- Subcutaneous injection
- Frequency
- Weekly
- Timing
- Fixed day
- Duration
- Continuous blocks
Our read
The mechanism is genuinely interesting and the phase 2 data is real. The reasoning fails on what phase 3 exists to find out: effect sizes commonly shrink, and the safety questions that matter — particularly around the glucagon component and cardiovascular effects — are exactly what a completed programme would answer. Running it now means accepting the risk the trials were designed to characterise, without any of the monitoring that made them safe.
What the community reports
The comparison is between how sure the community is and how much is actually known — evidence strength, not direction. A compound can have solid research that came out negative.
Treated as the next step up before any phase 3 result exists. Enthusiasm rests almost entirely on published phase 2 numbers being extrapolated, and the discussion rarely engages with why phase 3 exists.
Commonly reported as helping
- Faster loss than reported for approved incretins by people who used those first
- Reports of energy or warmth attributed to the glucagon component
Also reported, when it goes wrong
- Gastrointestinal effects reported as more pronounced
- Elevated resting heart rate, noticed by people wearing trackers
- Considerable uncertainty about what people have actually received
Why these reports can mislead
Every report here comes from unverified material of unknown identity and concentration. A person reporting a strong effect and a person reporting none may not have taken the same thing, at the same amount, or the compound at all — which makes the aggregate uninterpretable rather than merely noisy.
Direct quotations are not published here yet. We will only carry verbatim reports once they are sourced, dated and checked — an unattributed quote is a testimonial, and testimonials are exactly what this section exists to replace.
Watch for, in this use specifically
- Dose-dependent heart-rate increases were reported in trials. Nobody is monitoring that outside one.
- Unapproved supply means no verified identity or concentration — the failure mode is arithmetic, not pharmacology.
- Larger effect sizes mean faster loss, which makes lean-mass loss worse, not better.
Active clinical trials
- NCT00000003Phase 3Recruitingn = 2,100
Triple receptor agonist in obesity — phase 3 programme
Obesity · United States, United Kingdom · updated 15 Jul 2026
What remains unknown
The questions that would change our assessment if they were answered.
- Do phase 2 weight reductions hold up in phase 3?
- What is the long-term cardiovascular effect of the glucagon-agonist component?
- What happens to lean mass at the larger effect sizes reported?
References
Editorial change history
When we change a grade or a regulatory note, we log it here rather than editing quietly.
Added grey-market supply safety signal at serious severity.
Spotted something wrong? Tell us — we publish corrections.