SmartPeptide
Start Free
Fat LossInvestigational — Phase 3Limited human evidence FDA-approved label on file

Retatrutide

Eli Lilly's triple agonist (GLP-1 / GIP / glucagon receptor). Currently the most potent weight-management investigational drug — Phase 2 trials reported ~24% body weight reduction at the highest dose. Phase 3 TRIUMPH program ongoing. Not yet FDA-approved.

Educational only — not medical advice. SmartPeptide does not prescribe, diagnose, or treat. Always consult a licensed healthcare provider before using any peptide, supplement, medication, or protocol.

What the research shows

Phase 2 trial (n≈338, 48 weeks): ~24.2% mean body weight reduction at 12 mg weekly vs. ~2.1% placebo. Type 2 diabetes Phase 2 showed superior HbA1c reduction vs. dulaglutide. Phase 3 TRIUMPH program is ongoing across weight management, T2D, MASH, and cardiovascular outcomes.

What's still experimental

All commercial availability — Retatrutide is investigational and NOT FDA-approved as of mid-2026. Long-term cardiovascular and oncologic safety, durability after stopping, and pediatric use are all open questions awaiting Phase 3 read-outs (expected 2026-2027).

Anecdotal / community reports

Grey-market research-chemical supplies have appeared online. Quality and identity verification of these supplies is essentially impossible without lab analysis. Anecdotal self-experimentation logs are circulating but do not represent vetted human-trial data.

Anecdotal reports are NOT scientific evidence. They reflect personal experience and may not generalize.

FDA approval status

Source: openFDA + DailyMed (NIH/NLM)
0 FDA-approved labels on file· 10 on DailyMed

Doses studied in research

Source: Published clinical trial

What published trials tested or FDA-approved labels specify. Reporting research facts — not a SmartPeptide recommendation.

Phase 2 trialJastreboff et al., NEJM 2023 (Phase 2 obesity trial)
Indication studied: Weight management (Phase 2 — not FDA-approved)
Citation: Jastreboff AM et al., NEJM 2023;389:514-526
Phase 2 low
500µg
once weekly · subcutaneous

Lowest tested arm (n≈68)

Open calculator
Phase 2 mid
4mg(4,000 µg)
once weekly · subcutaneous

Mid-range arm (n≈68)

Open calculator
Phase 2 high
12mg(12,000 µg)
once weekly · subcutaneous

Highest tested arm (n≈68) — ~24.2% body weight reduction at 48 weeks

Open calculator

Notes from the source: Phase 3 TRIUMPH program ongoing. These doses are RESEARCH-TRIAL DOSES, not FDA-approved.

Important framing: The numbers above are what published trials tested or what FDA-approved labels specify. They are NOT a SmartPeptide recommendation for you. Trial doses come paired with screening, monitoring, and clinician oversight. Always consult a licensed clinician before any peptide use.

How clinicians typically protocol this

Third-party reference · not our recommendation

Dosing phases, cycle lengths, and administration timing as listed in a compounding-pharmacy clinician reference guide. Shown so you can see what a real protocol looks like — and bring informed questions to a licensed clinician.

Third-party protocol referenceCompounding-pharmacy clinician protocol reference (Nov 2025)

Dose numbers, frequencies, and cycle lengths in this panel are extracted from a clinician-facing reference protocol distributed by a US-based compounding pharmacy in November 2025. SmartPeptide has paraphrased all descriptive text and adds no endorsement. Always consult a licensed clinician.

Additional caution for Retatrutide

Retatrutide is not FDA-approved. Long-term human safety data is limited.

Metabolic

Investigational triple agonist of GIP, GLP-1, and glucagon receptors; investigational — Phase 3 as of 2025.

Protocol phases

Acclimation
1 mgonce weekly
subcutaneous
Starting
2 mgonce weekly
subcutaneous

may be increased to 4 mg after ≥4 weeks

Titration
+2 mgevery ≥4 weeks
subcutaneous
Maximum
8 mgonce weekly
subcutaneous
Cycle length

Ongoing; ≤6 doses per vial (stability guardrail).

Administration timing

Slow titration reduces GI side effects.

Reported side effects
NauseaConstipationGI intolerance during titration
Reconstitution calculator Storage & reconstitution guide
Not medical advice. SmartPeptide does not prescribe, diagnose, or treat. The protocol above reproduces dose figures from a third-party clinician reference so you can see what compounding-pharmacy guidance typically looks like — it is not a recommendation for you, and it has not been validated against peer-reviewed dose-ranging trials. Many of these compounds are not FDA-approved for human use. Work with a licensed clinician familiar with peptide therapy before considering anything here.

FDA enforcement & recalls

Live · openFDA Drug Enforcement API
Total actions
1
recalls + withdrawals
Ongoing
1
not yet completed
Class I (serious)
0
health hazard / death risk
  • Class IIOngoing· Voluntary: Firm initiated
    FDA record

    Retatrutide for Injection, 60mg / 10mL vial, all presentations, GenoGenix, LLC, 2840 NW 2nd Ave Ste 204 Boca Raton, FL 33431-6692

    Reason: Lack of Assurance of Sterility

    Jul 30, 2025·GenoGenix LLC
FDA classifications: Class I = reasonable probability of serious adverse health consequences or death. Class II = temporary or medically reversible adverse consequences. Class III = unlikely to cause adverse health consequences.

Mechanism & targets

ChEMBL · UniProt · Open Targets

Molecule (ChEMBL)

View on ChEMBL
Known mechanisms of action
  • CHEMBL1985
    agonistGlucagon receptor agonist
  • CHEMBL1784
    agonistGlucagon-like peptide 1 receptor agonist
  • CHEMBL4383
    agonistGastric inhibitory polypeptide receptor agonist

Live research

PubMed · ClinicalTrials.gov · Europe PMC · OpenAlex
PubMed papers
183
total
Human studies
0
MeSH: humans
Clinical trials
0
published
Active trials
3
34 total registered

Clinical trials (ClinicalTrials.gov)

All trials for "retatrutide"

Europe PMC — 850 additional records

Includes EU/UK studies and PubMed Central full-text articles. Often surfaces research weeks before PubMed indexes it.

Research volume (OpenAlex topic graph)

Total works
1,614
all years
Last 5 years
1,607
recent activity
Open access
1,456
freely readable
OA share
90%
of all works

Human clinical evidence

Semantic Scholar · AI TLDRs · influence-ranked
Semantic Scholar API is currently rate-limited.

Human-study summaries for “retatrutide OR LY3437943” are available on Semantic Scholar but the shared free-tier API quota is exhausted right now. Try refreshing in a few minutes, or check the PubMed and Europe PMC panels above for the same literature.

Research funding & verification

NIH RePORTER · CrossRef DOI registry

Publication landscape

CrossRef · DOI registry
Indexed works (CrossRef)
194
all DOIs registered
Retracted papers
0
no retractions on record
Top funders of indexed research
  • Eli Lilly and Company16 works
  • National Cancer Institute2 works
  • Martin-Luther-Universität Halle-Wittenberg2 works
  • Fundamental Research Funds for the Central Universities2 works
  • Emory University1 works
  • Development Fund of the Affiliated Hospital of Xuzhou Medical University1 works

Funder diversity is a credibility signal. Research concentrated in a single drug company's funding warrants more scrutiny than research funded across NIH, charities, and academic grants.

Preprints — cutting edge

bioRxiv · medRxiv · via Europe PMC

Preprints have NOT been peer-reviewed. They are early research shared by authors before formal validation. Treat findings as preliminary.

Showing 6 of 12 preprints indexed by Europe PMC.

Known risks

GI side effects (nausea, vomiting, diarrhea) — class-typical for incretin agonists, often dose-limiting. Theoretical concerns about glucagon receptor activation effects on glucose regulation, lipid metabolism, and liver function are being evaluated in Phase 3. Not yet approved — long-term safety unknown.

Reported side effects

Nausea (most common), vomiting, diarrhea, constipation, decreased appetite, injection-site reactions. Some studies note slightly elevated heart rate vs. semaglutide.

FDA adverse event reports (FAERS)

Updated quarterly by FDA
Reports filed
44
FAERS, all years
Serious reports
33
75% of reports
Top reporting countries
  • US6

Most-reported reactions

  • Vomiting
    8
  • Nausea
    7
  • Fatigue
    4
  • Heart Rate Increased
    4
  • Illness
    4
  • Product Use In Unapproved Indication
    4
  • Abdominal Pain
    3
  • Burning Sensation
    3
  • Feeling Abnormal
    3
  • Product Advertising Issue
    3

Counts from FDA Adverse Event Reporting System (FAERS). Voluntary reports — they show what was reported, not whether the drug caused the event. Many reports lack confirmation. FAERS docs

What requires medical supervision

Available ONLY through approved clinical trials. Any non-trial source is unverified and unsafe. Patients wanting to access GLP-1-class treatment should pursue FDA-approved options (Semaglutide, Tirzepatide) under licensed prescriber care while awaiting Retatrutide approval.

Questions for your clinician

  • Am I a candidate for an active Retatrutide trial in my area?
  • While we wait for approval, what's the best FDA-approved alternative for my situation?
  • What's your view on long-term metabolic adaptation with triple-agonist treatment?

Editorially curated references

Discussions about Retatrutide

Start a discussion
No discussions yet — be the first. Share what you've learned, what worked, what didn't, or a study you want translated into plain English.
See all Retatrutide discussions Native, moderated, no buying or selling