Does retatrutide cause low blood pressure, dizziness or fainting?

What do the posted trial tables report for dizziness and hypotension?

NCT04881760 reports dizziness, postural dizziness and hypotension as separate other-event rows, not as one low-blood-pressure endpoint.

These are the study arms of the cited trials, not an application protocol for research vials.

In that phase 2 obesity trial (n = 338), participants received placebo or retatrutide (LY3437943) subcutaneously once weekly for 48 weeks, with other events collected up to 52 weeks, in six labeled arms from 1 mg to 12 mg, a parenthetical milligram marking an arm's lead-in dose (NCT04881760 armGroups; PMID 37366315). Hypertension was recorded in more participants than hypotension (NCT04881760, otherEvents).

The phase 2 type 2 diabetes trial used the same route and schedule, with other events collected through study completion, up to 280 days (NCT04867785 armGroups). Dizziness there was 3/24 in the 8 mg (4 mg) arm versus 1/45 placebo, and its posted other-events table carries no hypotension row (NCT04867785, otherEvents).

Did the trials report fainting, syncope or presyncope?

The data-sheet review found no syncope, presyncope or fainting number specific to retatrutide, and a PubMed esearch on 2026-09-17 for retatrutide with dizziness, orthostatic, syncope or presyncope returned 0 hits.

The NCT04881760 serious-event table lists 14 terms across 7 arms (n = 338); none is syncope or presyncope (NCT04881760, seriousEvents). The other-events table is not a complete inventory: it reports a term only at 5% or more in at least one group, so a term missing from it stayed below 5% in every arm, which is not the same as not having occurred. Only the serious-event table is complete.

What did retatrutide do to blood pressure in the pooled analyses?

Retatrutide meta-analyses reported blood-pressure reductions versus placebo (PMID 42371360; PMID 40291085). The phase 2 paper reported dose-dependent heart-rate increases (PMID 37366315).

Jastreboff et al. reported that dose-dependent increases in heart rate peaked at 24 weeks and declined thereafter (PMID 37366315). A 2026 incretin meta-analysis of 85 RCTs (90,977 participants) reported the largest blood-pressure reduction versus placebo for triple receptor agonists (systolic 6.6 mmHg, diastolic 2.1 mmHg) and for dual agonists (systolic 5.1 mmHg, diastolic 1.8 mmHg), with no increase in hypoglycaemia (RR 1.05, 95% CI 0.83 to 1.33) (PMID 40899050). Two retatrutide-only meta-analyses report reductions versus placebo: WMD -6.79 mmHg systolic (95% CI -8.36 to -5.23, p<0.0001, I2 = 20%) with WMD -2.46 mmHg diastolic (95% CI -3.25 to -1.67) (PMID 42371360), and, in 3 RCTs with 878 patients, MD -9.88 mmHg systolic and -3.88 mmHg diastolic, all with p<0.00001 (PMID 40291085, PMC12026077). Those are pooled blood-pressure changes, not dizziness or syncope rates.

What do approved GLP-1 labels say about hypotension and fluid loss?

Approved semaglutide labeling quantifies hypotension and syncope, the searched Mounjaro label contains neither word, and both warn about volume depletion from gastrointestinal fluid loss.

PeptidesDirect does not sell semaglutide. PeptidesDirect does not sell tirzepatide.

The Wegovy DailyMed SPL (setid ee06186f-2aa3-4990-a760-757579d8f77b, updated June 30, 2026, section 6.1) reports hypotension, orthostatic hypotension and decreased blood pressure in 1.3% of Wegovy-treated adults versus 0.4% on placebo in the adult weight trials, and syncope in 0.8% versus 0.2%. The same section states that hypotension and orthostatic hypotension were more frequently seen in patients on concomitant antihypertensive therapy. Those percentages are semaglutide figures, not retatrutide figures.

A full-text search of the Mounjaro DailyMed SPL (setid d2d7da5d-ad07-4228-955f-cf7e355c8cc0, September 2, 2026) for hypotension and syncope returned 0 occurrences. Both that SPL and the Wegovy SPL carry a volume-depletion warning in section 5.5: “The majority of the reported events occurred in patients who experienced gastrointestinal adverse reactions leading to dehydration such as nausea, vomiting, or diarrhea.” That warning concerns fluid loss, not a retatrutide syncope rate.

What is still unknown, and what are people reporting online?

The ClinicalTrials.gov search for retatrutide on 2026-09-17 found no phase 3 study with posted results, and forum questions map what people ask, not an incidence rate.

A ClinicalTrials.gov query for retatrutide on 2026-09-17 found no phase 3 study with posted results: TRIUMPH-1 (NCT05929066), TRIUMPH-2 (NCT05929079), TRIUMPH-3 (NCT05882045) and TRIUMPH-4 (NCT05931367) are completed with hasResults: False, and the phase 3b study NCT06859268 (n = 643, completion 2028-04) has none either, so nothing here is said about its outcomes.

In the Reddit corpus we track, 177 question posts in 12 months and 6 in the 13 to 17 September 2026 window matched retatrutide with dizziness, fainting or low-blood-pressure wording. Those are anonymous reports: they show what people ask, never how often something happens.

Products mentioned

Retatrutidemetabolic

Retatrutide (LY3437943) is a synthetic 39-amino-acid peptide that acts on three receptors at once: GLP-1, GIP and glucagon. Supplied as a lyophilized powder for in-vitro research, with a batch-specific third-party certificate of analysis.

Sources

1. ClinicalTrials.gov. NCT04881760. otherEvents (dizziness, dizziness postural, hypotension, hypertension); seriousEvents (14 terms); armGroups (subcutaneous, once weekly, 48 weeks dosing, AE window up to 52 weeks).
2. ClinicalTrials.gov. NCT04867785. otherEvents (dizziness, no hypotension row); armGroups (SC injection once weekly); Baseline Through Study Completion (Up to 280 Days).
3. Jastreboff AM et al. 2023. N Engl J Med 389(6):514-526. PMID 37366315.
4. Basile C et al. 2026. Eur J Prev Cardiol 33(7):1210-1217. PMID 40899050.
5. Simental-Mendia LE et al. 2026. High Blood Press Cardiovasc Prev 33(5):503-516. PMID 42371360.
6. Abdrabou Abouelmagd A et al. 2025. Proc (Bayl Univ Med Cent). PMID 40291085. PMC12026077.
7. DailyMed. WEGOVY SPL. setid ee06186f-2aa3-4990-a760-757579d8f77b. Updated Jun 30 2026. Sections 6.1 and 5.5.
8. DailyMed. MOUNJARO SPL. setid d2d7da5d-ad07-4228-955f-cf7e355c8cc0. Sep 02 2026. Section 5.5.
9. ClinicalTrials.gov. TRIUMPH-1 NCT05929066, TRIUMPH-2 NCT05929079, TRIUMPH-3 NCT05882045, TRIUMPH-4 NCT05931367. Completed, hasResults: False. Query date 2026-09-17.
10. ClinicalTrials.gov. NCT06859268. Phase 3b, n = 643, completion 2028-04. hasResults: False.
11. PubMed eutils esearch, 2026-09-17. Query: retatrutide AND (dizziness OR orthostatic OR syncope OR presyncope). 0 hits.

Research use only. Retatrutide is supplied for laboratory in-vitro research, not for human or animal administration, and not as a medicine. Nothing in this article is a protocol, a recommendation or medical advice.