Retatrutide heart rate in the trials
Heart rate went up on retatrutide in a dose-related way, and the rise was largest in the first months. The published figures:
| Trial | Finding |
|---|---|
| Phase 2 obesity, 48 weeks[1] | Dose-dependent increase that peaked at 24 weeks and declined at 36 and 48 weeks |
| Phase 2 type 2 diabetes, 36 weeks[2] | Pulse up by as much as about 7 bpm early in treatment; at 36 weeks +0.03 to +4.34 bpm across doses, vs −3.16 on placebo and +1.76 on dulaglutide |
| Phase 3 trials | Heart rate magnitude not given in the published abstracts or Lilly announcements (checked November 13, 2026) |
For comparison, the FDA label for tirzepatide (Zepbound) reports a mean heart-rate increase of 1 to 3 beats per minute, against no increase on placebo.[6] The two numbers come from different trials and are not directly comparable.
Heart rhythm events
In the phase 2 obesity trial, cardiac arrhythmia events were reported in 11% of people on 12 mg and 14% in one 8 mg group, against 3% on placebo. They were mostly mild to moderate. One was severe: a prolonged QT interval in a person taking the anti-nausea drug ondansetron.[1]
Retatrutide blood pressure
Blood pressure improved rather than rose. The TRIUMPH-4 paper reports that in the full TRIUMPH-1 population of 2,339 people, retatrutide improved systolic blood pressure, along with triglycerides, non-HDL cholesterol, hsCRP and fasting insulin.[3] The exact figures are in the paper's supplementary tables, which we have not reproduced here.
For context, tirzepatide's FDA label shows systolic pressure falling about 4 to 7 mmHg more than on placebo. It also reports low blood pressure (hypotension) in 1.6% of people on Zepbound against 0.1% on placebo, and 2.2% in people already taking blood-pressure medicines.[6] Retatrutide has no label yet, so equivalent official numbers do not exist.
Heart outcomes: what TRIUMPH-3 showed
TRIUMPH-3 enrolled 1,949 people with a BMI of 35 or more and established heart disease. Lilly reported a hazard ratio of 1.12 (95% CI 0.64–1.96) for major cardiovascular events (MACE-3) and 0.82 (0.55–1.22) for the broader MACE-5. Lilly said there were fewer events than expected, so these estimates are imprecise and do not show either harm or benefit.[4]
The definitive answer will come from TRIUMPH-Outcomes, a 10,000-person cardiovascular and kidney outcomes trial due to complete its main phase in February 2029.[5]
Drug interaction study with metoprolol
A completed phase 1 study (NCT06808802) looked at how retatrutide affects levels of metoprolol, a common heart-rate and blood-pressure medicine, in healthy volunteers. ClinicalTrials.gov listed no posted results on November 13, 2026.[5]
Related
- Retatrutide side effectsAll reported events by dose
- How retatrutide worksThe three receptors
- Clinical trials trackerIncluding the outcomes trial
Frequently asked questions
Does retatrutide raise heart rate?
Does retatrutide lower blood pressure?
Systolic blood pressure improved in the TRIUMPH-1 population, according to the TRIUMPH-4 NEJM paper. The exact figures are in its supplement.[3]
Sources
- Jastreboff AM et al. Triple-hormone-receptor agonist retatrutide for obesity: a phase 2 trial
- Rosenstock J et al. Retatrutide in people with type 2 diabetes: a phase 2 trial
- Schnitzer TJ et al. Retatrutide in obesity and knee osteoarthritis (TRIUMPH-4, TRIUMPH-1-OA), author accepted manuscript
- Lilly: retatrutide successful in two additional phase 3 obesity trials (TRIUMPH-2, TRIUMPH-3)
- Retatrutide studies (NCT04881760, NCT05929066, NCT05931367, NCT06662383, NCT07629401 and others)
- Zepbound (tirzepatide) prescribing information
- Schnitzer TJ et al. Retatrutide in obesity and knee osteoarthritis (TRIUMPH-4)