Retatrutide Clinical Trials: Results & How to Enroll

TRIUMPH-1 Phase 2 full breakdown, ongoing Phase 3 trial design, NCT numbers, enrollment eligibility, and FDA approval timeline analysis.

Trial Status Dashboard

TRIUMPH-1

Phase 2
Completed
NCT ID: NCT04867785
Enrolled: 338 participants
Population: Adults with obesity (BMI 30–50) without diabetes
Primary Endpoint: Percent change in body weight at 48 weeks
Key Result: 24.2% mean weight reduction at 24mg dose at 48 weeks

TRIUMPH-3

Phase 3
Ongoing — enrolling
NCT ID: NCT05703841
Population: Adults with obesity (BMI ≥30 or ≥27 with comorbidity)
Primary Endpoint: Percent weight change and proportion achieving ≥5% weight loss

TRIUMPH-CVOT

Phase 3
Ongoing
NCT ID: NCT05882045
Population: High cardiovascular risk patients with obesity
Primary Endpoint: Major adverse cardiovascular events (MACE)

TRIUMPH-1 Deep Dive: What the Data Shows

Publication: New England Journal of Medicine, September 2023
DOI: 10.1056/NEJMoa2301972
Sponsor: Eli Lilly and Company
Participants: 338
Duration: 48 weeks treatment + 24 weeks post-treatment
Design: TRIUMPH-1, Phase 2, 6-arm parallel

Study Population

TRIUMPH-1 enrolled adults aged 18 years and older with a body mass index (BMI) of 30–50 kg/m² who did not have type 2 diabetes. Key exclusion criteria included prior GLP-1 receptor agonist use within 6 months, bariatric surgery within 2 years, and significant cardiovascular events within 6 months. The population was intentionally non-diabetic to isolate the drug's obesity-specific effects from glucose-lowering effects.

The Six Treatment Arms

ArmFinal DoseMean Weight Loss at 48 Weeksvs Placebo
PlaceboPlacebo-2.1%
Retatrutide 1mg1mg-7.5%+5.4% additional
Retatrutide 4mg4mg-13.7%+11.6% additional
Retatrutide 8mg8mg-17.3%+15.2% additional
Retatrutide 12mg12mg-22.8%+20.7% additional
Retatrutide 24mg24mg-24.2%+22.1% additional

Why Did 24mg Outperform 12mg?

The additional 1.4 percentage points between 12mg (22.8%) and 24mg (24.2%) reflect dose-dependent receptor saturation dynamics. At higher doses, glucagon receptor occupancy increases disproportionately, driving additional thermogenesis. The titration protocol for the 24mg arm also ran longer — participants spent more weeks at the therapeutic dose before the 48-week endpoint, allowing more cumulative weight loss. Phase 3 trials will clarify whether this difference holds in larger populations.

Safety Data from TRIUMPH-1

The most common adverse events were gastrointestinal: nausea, vomiting, diarrhea, and decreased appetite — consistent with the GLP-1 class. These occurred most frequently during dose titration and diminished after reaching stable dose. Discontinuation due to GI events was higher in the 24mg arm than lower dose arms, but the majority of participants completed the trial. No unexpected safety signals emerged in Phase 2.

TRIUMPH-3: The Phase 3 Trial

TRIUMPH-3 (NCT05703841) is the pivotal Phase 3 trial Eli Lilly needs to support an FDA New Drug Application for retatrutide. It differs from TRIUMPH-1 in several important ways:

Population
TRIUMPH-1: N=338, BMI 30–50, no T2D
TRIUMPH-3: Larger N, BMI ≥30 or ≥27 with comorbidity, includes more diverse population
Duration
TRIUMPH-1: 48 weeks treatment
TRIUMPH-3: Longer treatment period to demonstrate sustained efficacy
Primary endpoint
TRIUMPH-1: Percent weight change at 48 weeks
TRIUMPH-3: Percent weight change AND proportion achieving ≥5% weight loss
Statistical power
TRIUMPH-1: Phase 2 — dose-finding
TRIUMPH-3: Phase 3 — powered for regulatory approval

TRIUMPH-CVOT: Why a Cardiovascular Trial Matters

The FDA now requires cardiovascular outcomes trials (CVOTs) for new obesity drugs. TRIUMPH-CVOT (NCT05882045) enrolls high-cardiovascular-risk patients with obesity and tracks major adverse cardiovascular events (MACE) as the primary endpoint.

A positive CVOT dramatically changes the commercial picture. Semaglutide's SELECT trial (2023) showed 20% MACE reduction in obese patients without diabetes — this expanded Wegovy's indicated population to include cardiovascular risk patients and triggered Medicare Part D coverage. If retatrutide achieves similar results, it would be prescribed to millions of patients who currently cannot afford or access GLP-class drugs.

How to Enroll in an Active Retatrutide Trial

TRIUMPH-3 (NCT05703841) is actively enrolling as of 2026. Visit ClinicalTrials.gov and search for the NCT number to find enrolling sites near you.

General Eligibility Checklist

Likely Eligible If:
  • BMI ≥30, or ≥27 with hypertension/dyslipidemia
  • No GLP-1 drug use in past 6 months
  • Stable weight for 3+ months prior
  • No diabetes requiring insulin
  • No recent bariatric surgery (typically 2 years)
Likely Ineligible If:
  • History of MTC or MEN2 syndrome
  • Active or recent pancreatitis
  • Pregnant or planning pregnancy
  • Severe kidney disease
  • Significant cardiovascular event in past 6 months

What Trial Participation Involves

AspectTypical Requirements
Study drugFree — provided at no cost to participants
Study visitsRegular clinic visits (typically every 4–8 weeks) for assessments, labs, weight checks
Duration commitment12+ months for Phase 3 trials
CompensationVaries by site — many reimburse travel expenses, some provide additional stipends
RandomizationSome participants receive placebo — you may not receive active drug
MonitoringFrequent lab work, vital signs, potentially ECG and imaging

Timeline to FDA Approval

2023: TRIUMPH-1 results published in NEJM. Phase 2 complete.
2024–2025: TRIUMPH-3 Phase 3 enrollment and treatment underway.
2026: TRIUMPH-3 anticipated completion. Data analysis and NDA preparation.
2026–2027: FDA New Drug Application (NDA) submission by Eli Lilly.
2027–2028: FDA review and potential approval. If approved, pharmacy availability.

Frequently Asked Questions

What is the NCT number for the main retatrutide trial?

TRIUMPH-1 (Phase 2, completed) has NCT ID: NCT04867785. TRIUMPH-3 (Phase 3, enrolling) is NCT05703841. TRIUMPH-CVOT (Phase 3) is NCT05882045. You can look up current enrollment status at ClinicalTrials.gov.

Where was TRIUMPH-1 published?

TRIUMPH-1 results were published in the New England Journal of Medicine on September 21, 2023 (DOI: 10.1056/NEJMoa2301972). The trial was sponsored by Eli Lilly and Company. The publication reported 24.2% mean weight loss at 24mg over 48 weeks in 338 participants.

How is TRIUMPH-3 different from TRIUMPH-1?

TRIUMPH-1 was a Phase 2 trial (N=338) designed to establish dose-response relationships and safety signals. TRIUMPH-3 is a Phase 3 trial with a larger population (broader BMI range, including those with comorbidities like hypertension), longer duration, and co-primary endpoints that include cardiovascular secondary outcomes. Phase 3 data will support the FDA New Drug Application.

Can I enroll in a retatrutide trial right now?

As of 2026, TRIUMPH-3 (NCT05703841) is actively enrolling. Eligibility typically requires: BMI ≥30, or BMI ≥27 with at least one weight-related comorbidity (hypertension, dyslipidemia, etc.), no prior GLP-1 drug use within 6 months, no type 2 diabetes requiring insulin, and stable body weight for preceding 3 months. Visit ClinicalTrials.gov and search NCT05703841 to find enrolling sites and verify current eligibility criteria.

What is the TRIUMPH-CVOT trial?

TRIUMPH-CVOT (NCT05882045) is a Phase 3 cardiovascular outcomes trial enrolling patients with obesity and high cardiovascular risk. The primary endpoint is major adverse cardiovascular events (MACE — heart attack, stroke, CV death). This type of trial is now required by the FDA for obesity drugs. Positive CVOT data, as seen with semaglutide (SELECT trial), dramatically expands the indicated population and reimbursement coverage.

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Medical Disclaimer: Clinical trial information is based on publicly available data from ClinicalTrials.gov and published research. This content does not constitute medical advice.

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