Angiotensin-(1-7)
Angiotensin-(1-7), the Mas receptor arm of the renin-angiotensin system
Written by Aaron CuhaReviewed Sep 2026
Also known as: Ang-(1-7), TXA127, Angiotensin 1-7
The counter-regulatory arm of the renin-angiotensin system, made from angiotensin II by ACE2. It has been given to people in cancer, transplant and COVID-19 trials; the phase 1 cancer study recorded a stroke and a reversible cranial neuropathy as dose-limiting toxicities, and most of the company programme was terminated or withdrawn.
Overview
Angiotensin-(1-7) is a 7 amino acid peptide, sequence DRVYIHP, cut from angiotensin II by ACE2. It signals through the Mas receptor and opposes the vasoconstrictive, pro-fibrotic AT1 arm of the same system. That opposition is the entire basis for the longevity and tissue-repair claims made for it, and those claims are not what has been tested in people.
What has been tested in people is cancer, blood-count recovery after transplant, and COVID-19. A phase 1 dose-escalation study gave daily subcutaneous injections to 18 adults with advanced solid tumours; dose-limiting toxicities at 700 micrograms per kilogram included a grade 4 stroke and a grade 3 reversible cranial neuropathy, and the recommended phase 2 dose was set at 400 micrograms per kilogram. A phase 2 trial in 20 people with metastatic sarcoma reported median progression-free survival of 2.7 months and median overall survival of 10.2 months and failed to confirm the biomarker effect seen in phase 1. An investigator-initiated randomised trial in intensive care during COVID-19 enrolled 28 people in phase 1 and 79 in phase 2 before stopping early for slow recruitment; oxygen-free days did not differ in the phase 2 comparison (median 19 versus 14 days, p = 0.15).
It is not approved anywhere, for anything. The commercial programme under the code TXA127 ran a string of small trials, several of which were terminated for enrolment problems and three of which were withdrawn before enrolling anybody.
Mechanism of action
In humans, ACE2 converts angiotensin II to angiotensin-(1-7), which binds the Mas receptor (gene MAS1). Established human pharmacology is limited: the phase 1 study measured plasma concentrations and a fall in placental growth factor in the patients who had clinical benefit, and the phase 2 study confirmed a rise in plasma angiotensin-(1-7) 4 hours after injection but did not reproduce the biomarker change. The antifibrotic and cardioprotective mechanisms cited for this peptide come from rodent work and should not be read as human findings.
Human evidence
People have received this peptide in at least four published studies plus a registered programme of small trials: a phase 1 in advanced cancer, a phase 1/2 around breast cancer chemotherapy, a phase 2 in metastatic sarcoma, and a randomised intensive care trial during COVID-19. None of it addresses the uses the peptide is marketed for.
- Phase 1, 18 adults with advanced solid tumours: dose-limiting toxicities of grade 4 stroke and grade 3 reversible cranial neuropathy at 700 micrograms per kilogram; other toxicities generally mild; recommended phase 2 dose 400 micrograms per kilogram.
- Phase 2, 20 adults with metastatic sarcoma at 20 mg daily: treatment was tolerated, median progression-free survival 2.7 months, median overall survival 10.2 months, and the phase 1 biomarker signal did not replicate.
- Randomised COVID-19 intensive care trial, 79 people in the randomised phase: no difference in oxygen-free days (median 19 versus 14 days, p = 0.15). The trial stopped early for slow recruitment and the positive figure quoted elsewhere comes from pooling the open-label phase 1 with the randomised phase 2.
- Phase 1/2 dose escalation around chemotherapy in newly diagnosed breast cancer.
- Registry picture on 11 September 2026: of the TXA127 studies listed, three are WITHDRAWN with zero enrolment, three are TERMINATED (one explicitly for difficulty recruiting to a dosing cohort, one for enrolment feasibility), and the current Duchenne cardiomyopathy study is listed UNKNOWN. None of the completed studies has posted results in the registry.
What this does not tell you: Nothing here tests cardiovascular protection, fibrosis, tissue repair or ageing in people, which are the claims attached to this peptide outside the clinic. The trials that exist are small, in seriously ill populations, mostly single-arm, and several were stopped before they could answer anything. The one serious neurological toxicity signal comes from a dose-escalation study in people with cancer, so its relevance to other doses and populations is unknown, and it is a reason to be careful rather than a reason to be reassured.
Reading the research record
The gap between this peptide's reputation and its clinical record is instructive. The Mas receptor story is real physiology: ACE2 makes angiotensin-(1-7), it opposes the AT1 arm, and rodent models show antifibrotic and vasodilatory effects. Two separate companies built programmes on that, and the registry shows what happened. Tarix Pharmaceuticals ran transplant and blood-count trials, three of which were withdrawn without enrolling a single participant and two of which were terminated for enrolment problems. Constant Therapeutics later registered stroke and Duchenne cardiomyopathy studies that are listed with unverified status.
A 7 amino acid fragment of a human hormone is also hard to own, which shapes who is willing to fund a trial. The result is a literature of small studies in populations chosen because they were fundable, not because they were the best test of the mechanism. That is a reason the record is thin, not a demonstration that the peptide does nothing; it equally is not evidence that it does anything, and the phase 1 stroke and cranial neuropathy are a reminder that an endogenous peptide given at pharmacological doses is still a drug.
The evidence, charted
Fig. 1 · evidence composition
7of 8 citations (88%) are in people
Counted from the citation list on this page. The Human count is the same number shown in the badge at the top. Both understate any literature larger than the sources we cite.
Fig. 2 · evidence over time
Evidence spans 7 distinct years, 2006 to 2024, counted from the citation list on this page.
Fig. 3 · legal status at a glance
US
Not approved
UK
Approved
AU
Approved
CA
Not approved
Approved in 2 of 4, prescription route in 0, not approved in 2. A jurisdiction's classification is a regulatory fact, not a verdict on the science; see Legal status below for the full text and any notes.
Fig. 4 · dose response
No human dose response curve exists
We draw this figure where the data supports it. For this compound in humans it does not, so the panel stays empty rather than borrowing an animal curve and implying it transfers.
Key studies & citations
- Human2009
Phase I and pharmacokinetic study of angiotensin-(1-7), an endogenous antiangiogenic hormone
18 adults with advanced solid tumours received escalating subcutaneous doses daily for 5 days on a 3 week cycle. Dose-limiting toxicities at 700 micrograms per kilogram were a grade 4 stroke and a grade 3 reversible cranial neuropathy. One patient had a 19 percent tumour reduction and 3 more had disease stabilisation beyond 3 months. Recommended phase 2 dose 400 micrograms per kilogram.
Clinical Cancer Research - Human2016
Phase II Trial of Angiotensin-(1-7) for the Treatment of Patients with Metastatic Sarcoma
20 people with metastatic sarcoma received 20 mg subcutaneously daily. Median progression-free survival 2.7 months (95 percent confidence interval 1.4 to 4.1) and median overall survival 10.2 months (5.3 to 18.3). The placental growth factor biomarker effect seen in phase 1 was not confirmed. Two people with vascular sarcomas had prolonged disease stabilisation at 10 and 19 months.
Sarcoma - Human2024
Angiotensin-(1-7) infusion in COVID-19 patients admitted to the ICU: a seamless phase 1-2 randomized clinical trial
Investigator-initiated trial in two intensive care units: 28 people in the open-label phase 1 and 79 in the double-blind randomised phase 2, stopped early for slow recruitment. Oxygen-free days by day 28 did not differ in phase 2 (median 19 versus 14 days, p = 0.15). Pooling both phases gave a difference favouring treatment (p = 0.04), which is a post-hoc pooled comparison rather than the randomised result. One serious adverse event, bradycardia, was judged possibly related.
Annals of Intensive Care - Human2006
Phase I/II dose escalation study of angiotensin 1-7 administered before and after chemotherapy in patients with newly diagnosed breast cancer
Randomised multicentre dose-escalation study giving angiotensin-(1-7) around chemotherapy in newly diagnosed breast cancer, one of the earliest human exposures to this peptide.
Cancer Chemotherapy and Pharmacology - Review2016
Therapeutic uses for Angiotensin-(1-7)
Review of the therapeutic and patent landscape for the peptide and its analogues, describing the ACE2 and Mas receptor rationale that the clinical programme was built on.
Expert Opinion on Therapeutic Patents - Human2010
Acceleration of Platelet Recovery Following Autologous Peripheral Blood Stem Cell Transplantation (TXA127)
Phase 2, sponsor Tarix Pharmaceuticals, 75 participants enrolled, status TERMINATED, no results posted as of 11 September 2026.
ClinicalTrials.gov - Human2013
Efficacy Study of TXA127 to Reduce Graft-vs-Host Disease in Subjects Undergoing Allogeneic Transplant
Phase 2, sponsor Tarix Pharmaceuticals, status WITHDRAWN with zero participants enrolled. Two further TXA127 transplant trials, NCT01882374 and NCT01554254, are also listed WITHDRAWN with zero enrolment.
ClinicalTrials.gov - Human2023
TXA127 in Non-Ambulant Patients With Duchenne Muscular Dystrophy Cardiomyopathy
Phase 2, sponsor Constant Therapeutics, 10 participants planned. Status was UNKNOWN on 11 September 2026, meaning the record has not been verified recently by the sponsor.
ClinicalTrials.gov
Frequently asked questions
Has angiotensin-(1-7) been given to humans?
Yes. At least four published studies have given it to people: a phase 1 in 18 adults with advanced cancer, a phase 1/2 around breast cancer chemotherapy, a phase 2 in 20 people with metastatic sarcoma, and a randomised intensive care trial during COVID-19 that enrolled 107 people across its two phases.
Is it safe?
It has not been studied well enough to say. In the phase 1 cancer study, a grade 4 stroke and a grade 3 reversible cranial neuropathy were the dose-limiting toxicities at 700 micrograms per kilogram, and one possibly related bradycardia caused a discontinuation in the COVID-19 trial. Total published exposure is under 200 people, all in serious illness.
Does it protect the heart or reverse fibrosis in people?
No published human trial has tested that. The cardioprotective and antifibrotic evidence is from rodent models. The human trials are in cancer, transplant and COVID-19.
Is it approved anywhere?
No. It is investigational. The clinical programme under the code TXA127 includes three studies listed as withdrawn with zero enrolment and three terminated, and none of the completed studies has posted results in the registry.