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Retatrutide and Heart Rate: What Clinical Trials Reported

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PBIPeptide Bio Index Editorial DeskSource-labeled research summary
Source-limited8 min readUpdated Aug 28, 2026
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  1. Key takeaway
  2. Phase 2 obesity trial (NEJM) — what was reported about heart rate
  3. Phase 2 trial in people with type 2 diabetes (Lancet) — heart rate reporting status
  4. Phase 3 TRANSCEND-T2D-1 trial — heart rate reporting status
  5. Context from reviews and meta-analyses
  6. Gaps and what is not known from the reviewed excerpts
  7. Reported study-design details from cited sources
  8. Limitations and research gaps
  9. Documentation checklist
  10. Related research supplies
  11. More Retatrutide research
  12. Sources and references

Disclosure: Peptide Bio Index is affiliated with SourcePoint Research and may earn from qualifying purchases or affiliate links.

This article summarizes published research and reported study designs. It is not medical advice, dosing guidance, or a personal-use recommendation.

Source-limited research note: The reviewed sources were incomplete, ambiguous, or insufficient for a normal article. This page labels missing details rather than guessing.

This deep dive summarizes what the reviewed clinical-trial reports state about retatrutide and heart rate. Among the reviewed trial publications, the phase 2 obesity trial published in NEJM explicitly described heart-rate changes; other large trial reports in the provided record excerpts did not include heart-rate results in their reviewed excerpts (not reported in the reviewed source). The available clinical-trial excerpts therefore provide limited direct evidence on heart-rate magnitude and clinical consequences. (Sources: S4; S2; S3)

Key takeaway

The clearest trial-level statement about heart rate in the reviewed sources comes from the phase 2 obesity trial (Jastreboff et al., NEJM), which reported dose-dependent increases in heart rate that peaked at 24 weeks and declined thereafter. Other large trials and trial excerpts in the reviewed set (the phase 2 diabetes Lancet trial and the phase 3 TRANSCEND-T2D-1 trial) did not report heart-rate values or temporal heart-rate summaries in the provided excerpts (not reported in the reviewed source). (Sources: S4; S2; S3) [S4] [S2] [S3]

Phase 2 obesity trial (NEJM) — what was reported about heart rate

In the phase 2 randomized, double-blind, placebo-controlled trial in adults with obesity (NEJM), investigators reported dose-dependent increases in heart rate that peaked at 24 weeks and declined thereafter; the trial delivered once-weekly subcutaneous retatrutide (multiple dose arms) over a 48-week treatment period. The NEJM report specifically characterizes the heart-rate change as peaking at 24 weeks and then declining but does not provide detailed magnitude values for heart-rate increase in the reviewed excerpt. (Sources: S4) [S4]

Phase 2 trial in people with type 2 diabetes (Lancet) — heart rate reporting status

The phase 2 randomized, placebo- and active-controlled trial in adults with type 2 diabetes (Lancet) reported detailed efficacy and many safety outcomes (including gastrointestinal adverse events and absence of severe hypoglycaemia) and described dose arms and dosing schedules, but the provided excerpt does not present heart-rate values or a summary of heart-rate changes (not reported in the reviewed source). (Sources: S2) [S2]

Phase 3 TRANSCEND-T2D-1 trial — heart rate reporting status

The phase 3 TRANSCEND-T2D-1 report (Lancet, 40-week randomized trial) described efficacy (HbA1c and bodyweight) and an adverse-event profile consistent with GLP-1 agonists; the reviewed excerpt does not include heart-rate measurements or heart-rate change summaries (not reported in the reviewed source). (Sources: S3) [S3]

Context from reviews and meta-analyses

Reviews and a network meta-analysis in the reviewed set contextualize retatrutide as a triple-receptor agonist with gastrointestinal adverse events commonly reported and a higher overall adverse-event burden in some pooled analyses. These sources discuss safety more broadly (gastrointestinal events, AE risk comparisons) but do not provide trial-level heart-rate magnitude details beyond the phase 2 obesity trial's description in the NEJM excerpt. (Sources: S1; S5; S6; S8) [S1] [S5] [S6] [S8]

Gaps and what is not known from the reviewed excerpts

Critical details needed to interpret the clinical relevance of heart-rate changes are not available in the reviewed excerpts: the absolute or mean magnitude of heart-rate increase by dose, baseline heart-rate values, variability and confidence intervals, whether increases triggered clinical interventions, long-term trajectories beyond the trial timepoints, and whether findings were adjudicated as clinically significant. The phase 2 obesity trial notes timing (peak at week 24 and subsequent decline) but does not report magnitude in the provided excerpt; the phase 2 diabetes and phase 3 trial excerpts do not report heart-rate data (not reported in the reviewed source). (Sources: S4; S2; S3) [S4] [S2] [S3]

Reported study-design details from cited sources

The following table summarizes protocol details reported in cited studies. These details are provided as literature context only and are not recommendations or instructions.

Source Study Type Model / Subject Amount Reported Route Reported Frequency Duration Notes
[S4] Randomized, double-blind, placebo-controlled phase 2 trial Adults with obesity (BMI ≥30 or BMI 27– 1 mg; 4 mg (initial dose 2 mg or 4 mg); 8 mg (initial dose 2 mg or 4 mg); 12 mg (initial dose 2 mg) subcutaneous injection once weekly 48 weeks Dose arms included 1 mg, 4 mg (with initial-dose variants), 8 mg (with initial-dose variants), and 12 mg; the trial report states dose-dependent increases in heart rate that peaked at 24 weeks and declined thereafter. The reviewed excerpt does not provide numeric heart-rate magnitudes.
[S2] Randomized, double-blind, double-dummy, placebo- and active-controlled phase 2 trial Adults with type 2 diabetes (HbA1c 7.0–10.5%; BMI 25–50 kg/m2) 0.5 mg; 4 mg (starting dose 2 mg or no escalation); 8 mg (starting dose 2 mg or 4 mg); 12 mg (starting dose 2 mg) once-weekly injections once weekly primary endpoint at 24 weeks; efficacy also reported at 36 weeks Multiple retatrutide maintenance doses studied (0.5 mg, 4 mg with/without escalation, 8 mg with slow/fast escalation, 12 mg escalation); safety outcomes reported included gastrointestinal adverse events and no severe hypoglycaemia; heart-rate data are not presented in the provided excerpt (not reported in the reviewed source).
[S3] Randomized, double-blind, placebo-controlled phase 3 trial (TRANSCEND-T2D-1) Adults with type 2 diabetes inadequately controlled with diet and exercise (HbA1c 7.0–9.5%; BMI ≥23 kg/m2) 4 mg; 9 mg; 12 mg subcutaneous injection once weekly 40 weeks Participants randomized to retatrutide 4 mg, 9 mg, or 12 mg versus placebo; efficacy and general safety profile reported in the excerpt, but heart-rate measurements or summaries are not included in the reviewed excerpt (not reported in the reviewed source).

Limitations and research gaps

  • Only one reviewed trial excerpt (the phase 2 obesity NEJM report) explicitly mentions heart-rate changes; other large trial excerpts in the reviewed set did not include heart-rate data in the provided excerpts.
  • The NEJM excerpt reports timing (peak at week 24 and decline thereafter) but the reviewed excerpt does not include numeric magnitude, baseline heart rate, or statistical estimates for heart-rate change.
  • No reviewed excerpt provides long-term cardiac-outcome data or the clinical significance of the reported heart-rate changes.
  • Because reporting is incomplete across the reviewed sources, conclusions about frequency, magnitude, dose–response, or clinical impact of heart-rate changes with retatrutide cannot be robustly drawn from the provided records.

Documentation checklist

  • Confirm whether each reviewed trial report explicitly measured and reported heart rate.
  • Note the timing of peak heart-rate changes when reported (e.g., week 24 in the phase 2 obesity trial).
  • Differentiate trial populations (obesity vs type 2 diabetes) when interpreting safety signals.
  • Look for whether heart-rate magnitude, baseline values, and clinical thresholds were reported.
  • Interpret heart-rate findings in the context of other reported adverse events (eg, gastrointestinal AEs).
  • Study randomization and monitoring logs (documentation and inventory)
  • Temperature-monitored refrigerated storage for biological samples and labeled specimen boxes
  • Electronic case-report forms (eCRF) templates and audit-trail documentation
  • Laboratory-grade surface cleaning supplies and compatible disinfectant wipes for workspaces
  • Clinical-trial data-management software license documentation

Research organization supplies: Common tools used for research documentation workflows may include lab notebooks, label makers, sample storage boxes, inventory stickers, and temperature log sheets.

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Product listings, specifications, and availability can change. Review the current Amazon listing and manufacturer instructions before ordering. These links are for research organization and compatible surface/equipment-cleaning workflows, not personal-use guidance.

Research Supply Note: SourcePoint Research currently lists SPR-3RT for research-use-only sourcing. Review current availability and the exact batch documentation at SourcePointResearch.com. This article does not independently certify a SourcePoint batch. Peptide Bio Index is affiliated with SourcePoint Research.

More Retatrutide research

Sources and references

  1. [S1] Madsbad S, Holst JJ. The promise of glucagon-like peptide 1 receptor agonists (GLP-1RA) for the treatment of obesity: a look at phase 2 and 3 pipelines.. Expert opinion on investigational drugs. 2025. PMID: 40022548. DOI: 10.1080/13543784.2025.2472408
  2. [S2] Rosenstock J, Frias J, Jastreboff AM, Du Y, Lou J, Gurbuz S. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA.. Lancet (London, England). 2023. PMID: 37385280. DOI: 10.1016/S0140-6736(23)01053-X
  3. [S3] Bajaj HS, Welch M, Shah P, Luna E, Jaouimaa FZ, Liu B. Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial.. Lancet (London, England). 2026. PMID: 42250575. DOI: 10.1016/S0140-6736(26)00967-0
  4. [S4] Jastreboff AM, Kaplan LM, Frías JP, Wu Q, Du Y, Gurbuz S. Triple-Hormone-Receptor Agonist Retatrutide for Obesity – A Phase 2 Trial.. The New England journal of medicine. 2023. PMID: 37366315. DOI: 10.1056/NEJMoa2301972
  5. [S5] Sinha B, Ghosal S. Efficacy and Safety of GLP-1 Receptor Agonists, Dual Agonists, and Retatrutide for Weight Loss in Adults With Overweight or Obesity: A Bayesian NMA.. Obesity (Silver Spring, Md.). 2025. PMID: 40685589. DOI: 10.1002/oby.24360
  6. [S6] Katsi V, Koutsopoulos G, Fragoulis C, Dimitriadis K, Tsioufis K. Retatrutide-A Game Changer in Obesity Pharmacotherapy.. Biomolecules. 2025. PMID: 40563436. DOI: 10.3390/biom15060796
  7. [S7] Giblin K, Kaplan LM, Somers VK, Le Roux CW, Hunter DJ, Wu Q. Retatrutide for the treatment of obesity, obstructive sleep apnea and knee osteoarthritis: Rationale and design of the TRIUMPH registrational clinical trials.. Diabetes, obesity & metabolism. 2026. PMID: 41090431. DOI: 10.1111/dom.70209
  8. [S8] Drucker DJ. Efficacy and Safety of GLP-1 Medicines for Type 2 Diabetes and Obesity.. Diabetes care. 2024. PMID: 38843460. DOI: 10.2337/dci24-0003

Peptide Bio Index is affiliated with SourcePoint Research. Articles may link to SourcePointResearch.com and third-party affiliate products. As an Amazon Associate, Peptide Bio Index earns from qualifying purchases. Content is educational and research-literature focused only and is not medical advice, dosing guidance, or a personal-use recommendation.

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