Retatrutide, Heart Rate and Blood Pressure: What the Trials Found

Written by Olha Orlyk. Updated November 3, 2026.

Retatrutide lowered blood pressure in every trial that has reported it so far, but it also raised heart rate, mostly in the first months of treatment. In the Phase 2 trial, 24-hour monitoring showed systolic blood pressure (the top number) falling by about 8 to 12 mmHg at the higher doses, while resting pulse rose by up to about 9 beats per minute at 24 weeks before easing. Phase 3 TRIUMPH trials reported similar blood pressure drops of roughly 9 to 14 mmHg. The main blood pressure risk seen so far is the opposite of high blood pressure: hypotension, meaning pressure that drops too low, especially in people already taking blood pressure pills. Retatrutide, an investigational Eli Lilly drug acting on GIP, GLP-1 and glucagon receptors, is not FDA approved as of November 2026, and its effect on heart attacks and strokes will not be known until about 2029.

Based on the trials so far, blood pressure improved rather than worsened. In the Phase 2 obesity trial, 41% of people in the combined 8 mg groups and 30% in the 12 mg group stopped at least one blood pressure medicine during the study. That finding was exploratory.

Two issues matter for people with hypertension: pressure can fall too far when retatrutide is added to existing blood pressure pills, and heart rate rises, at least for a while. The net effect on heart attacks and strokes is not yet known. Outside a trial the question is moot for now: retatrutide can only be taken legally in a clinical study, where the team monitors blood pressure. For background on how the drug works, see what retatrutide is.

The most detailed data come from the 48-week Phase 2 obesity trial published in the New England Journal of Medicine in 2023. Some participants wore a cuff that takes readings around the clock for 24 hours (ambulatory monitoring). Some dose groups started at a lower dose and stepped up; the labels below show the starting dose in brackets. In clinic readings, systolic pressure fell about 5 to 8 mmHg in all dose groups except the 1 mg group, according to a TCTMD news summary.

The Phase 3 TRIUMPH trials, reported between December 2025 and October 2026, showed similar or larger drops. The TRIUMPH-1 numbers below come from a summary of the published NEJM paper rather than from Lilly directly, and we could not check them against the full paper.

In TRANSCEND-T2D-2, a comparison with Ozempic 2 mg, Lilly said systolic pressure improved more with retatrutide but gave no numbers. More on the diabetes and heart-disease trials is in our summary of the TRIUMPH-2 and TRIUMPH-3 results.

Yes. In the Phase 2 trial the authors reported dose-dependent increases in heart rate that peaked at 24 weeks and declined afterwards. On 24-hour monitoring, average pulse at the start was about 76 beats per minute. At week 24 it had risen by 9.2 bpm in the 12 mg group, against 0.8 bpm on placebo.

In TRIUMPH-1, according to a summary of the NEJM paper, heart rate peaked around week 20 at roughly 8 bpm above baseline with 12 mg and about 7 bpm with 9 mg, then settled to about 2.6 to 2.7 bpm above baseline by week 80, compared with a 0.3 bpm fall on placebo. The same summary reports a week-80 increase of 1.5 bpm on 12 mg in TRIUMPH-2, against a 1.0 bpm fall on placebo. Lilly has not released heart rate data for TRIUMPH-3 or TRIUMPH-4.

It appears to shrink but not disappear entirely. In Phase 2, the 12 mg group's 24-hour pulse increase fell from 9.2 bpm at week 24 to 6.7 bpm at week 36, and the paper's discussion notes further decline by weeks 36 and 48. In the longer Phase 3 trials, the reported increase at 80 weeks was about 1.5 to 2.7 bpm, which is in the same range as approved drugs in this class. Dose escalation in the first months is described in retatrutide dosage in clinical trials.

Averages hide individual variation: the Wegovy label notes that 26% of people had a rise of 20 bpm or more at some visit, compared with 16% on placebo. Comparable individual-level data for retatrutide have not been released.

The exact cause is not settled, so the following are hypotheses rather than proven mechanisms. GLP-1 drugs as a class raise heart rate slightly, possibly by acting on the heart's pacemaker region and shifting the nervous system towards the faster 'fight or flight' side. Glucagon, the third hormone retatrutide mimics, has long been known to increase heart rate and the force of heart contractions at high doses. A fall in blood pressure can also trigger a reflex speed-up of the heart. The trials were not designed to separate these effects.

A small number of heart rhythm events were reported, and most were mild. In the Phase 2 trial, cardiac arrhythmia adverse events were reported in 2 people (3%) on placebo, compared with 7 people (11%) on 12 mg and 5 people (14%) in the 8 mg group that started at 4 mg; two other dose groups had none. The authors described these events as mild to moderate, with one exception: a severe case of QT prolongation (a change on the heart tracing) in a participant who was also taking ondansetron, an anti-nausea drug that can itself affect QT. It resolved after the drug was stopped.

According to a summary of the published TRIUMPH-1 paper, severe or serious arrhythmia or conduction events occurred in 0.9% of people on retatrutide and 0.9% on placebo. In TRIUMPH-2, the same summary reports serious events in 1% on 12 mg against a single placebo case. Other side effects, such as skin sensations, are covered in our article on retatrutide dysesthesia.

Yes. Lilly's summary of TRIUMPH-1 listed hypotension among the most common adverse events of special interest and said it occurred more often in people taking antihypertensives. According to a summary of the published paper, hypotension was reported in 8.8% on retatrutide against 0.9% on placebo, rising to 11.3% against 1.3% in people on blood pressure medicines, and 14.0% of retatrutide users had their blood pressure medicines reduced, against 2.6% on placebo.

In TRIUMPH-2, in people with type 2 diabetes, hypotension was reported in 1%, 5% and 6% of the 4 mg, 9 mg and 12 mg groups, against under 1% on placebo, according to Pharmacy Times. In the Phase 2 obesity trial, a single hypotension event was reported at 12 mg and none on placebo, while reports of high blood pressure as an adverse event were 6.5% on 12 mg against 2.9% on placebo. Weight loss, eating and drinking less, and vomiting can all lower pressure.

TRIUMPH-3 enrolled 1,949 people with a BMI of 35 or more and established cardiovascular disease. Systolic pressure fell 9.3 mmHg at the highest dose. Lilly also reported major adverse cardiovascular events (MACE). For a five-part measure, there were 44 events on retatrutide and 52 on placebo (hazard ratio 0.82, 95% confidence interval 0.55 to 1.22). For the standard three-part measure of cardiovascular death, heart attack and stroke, there were 27 against 23 (hazard ratio 1.12, 0.64 to 1.96).

Both intervals cross 1, and Lilly noted that events occurred less often than expected, so the trial cannot show either benefit or harm. Questions about other long-term risks are discussed in does retatrutide cause cancer.

On blood pressure, retatrutide's reductions look at least as large as those of the approved drugs. In the SURMOUNT-1 substudy of tirzepatide (Zepbound, Mounjaro), 24-hour systolic pressure fell 7.4, 10.6 and 8.0 mmHg on 5, 10 and 15 mg at 36 weeks. On heart rate, the Wegovy label reports a mean rise of 1 to 4 bpm against placebo, and the tirzepatide substudy found rises of 2.1 to 5.4 bpm. Retatrutide's early Phase 2 peak was higher, but long-term Phase 3 figures are similar. Hypotension was reported in 1.3% on Wegovy against 0.4% on placebo, lower than the TRIUMPH-1 figure, though trials differ in design. For broader comparisons, see retatrutide vs tirzepatide and retatrutide vs Ozempic, Wegovy and Zepbound.

The answer will come from TRIUMPH-Outcomes, a trial of about 10,000 adults aged 45 or older with a BMI of 27 or more and either atherosclerotic cardiovascular disease, chronic kidney disease or both. Its main outcomes are a combination of heart attack, stroke, cardiovascular death or heart failure hospitalization, and a kidney outcome covering kidney failure, a sustained 40% drop in kidney function, and cardiovascular or kidney death. It started in April 2024, with an estimated primary completion date of February 2029. Lilly plans to submit retatrutide to the FDA in the first quarter of 2027, so approval, if it comes, would likely arrive before those results; our FDA approval watch tracks the timeline.

Retatrutide is not available by prescription, and online 'research peptides' are not the trial drug; our guide on how to get retatrutide explains the legitimate route, which is a clinical trial.

Retatrutide lowered blood pressure in every reported trial, by around 9 to 14 mmHg systolic at the highest doses. Heart rate rose, most at higher doses and in the first months, then eased to a few beats per minute above baseline by 80 weeks. The main practical risk for people with high blood pressure is pressure dropping too low when retatrutide is combined with blood pressure pills. Whether the drug reduces heart attacks and strokes remains unknown until TRIUMPH-Outcomes reports, expected around 2029.

This article summarizes published research for general information and is not medical advice. Retatrutide is investigational and not FDA approved. The trials cited were funded by Eli Lilly, the drug's developer; some TRIUMPH-1 and TRIUMPH-2 figures come from a secondary summary of the published papers and have not been checked against the full text.