What is Relaxin (Serelaxin)?

A pregnancy hormone that relaxes blood vessels; serelaxin is a recombinant form studied in acute heart failure.

Relaxin (Serelaxin) in the library · · Human Trials · What are peptides?

28 registered trials · 86 indexed papers · 114 human / 86 animal studies

From the PeptideWhiz library entry. "As described" sections summarize claims made in the sources; they are not PeptideWhiz endorsements.

What it is

A pregnancy hormone that relaxes blood vessels; serelaxin is a recombinant form studied in acute heart failure.

Type: Peptide hormone.

Definition (National Library of Medicine)

“A water-soluble polypeptide (molecular weight approximately 8,000) extractable from the corpus luteum of pregnancy. It produces relaxation of the pubic symphysis and dilation of the uterine cervix in certain animal species. Its role in the human pregnant female is uncertain. (Dorland, 28th ed)”

MeSH: Relaxin

Human research

The registered human trials and peer-reviewed human studies linked below are listed from ClinicalTrials.gov and PubMed. A study is linked only when Relaxin (Serelaxin) is one of its interventions, or is named in the study title or subject headings.

Listing a study does not mean it showed a benefit, and it is not medical advice.

Registered human trials (28)

Trial	Phase	Status	Year	Enrolled
Relaxin Therapy for Atrial Fibrillation	Phase 1/Phase 2	not yet recruiting	2027	208
Progressive Relaxation for COPD: Effects on Insomnia and Satisfaction		active not recruiting	2025	70
Effect of Autogenic Relaxation Therapy on Caregivers on Perceived Stress Quality of Life and Caregiver Burden		unknown	2024	64
Relaxin and Placental Volume in Placenta Accreta Spectrum		completed	2022	40
Relaxin, Matrix Metalloproteinase-2 and Interleukin-6 in Women With Chronic Pelvic Pain		completed	2022	60
"Study of the Effects of Serum and Follicular Fluid Relaxin Levels on Ovarian Function in IVF Cycles"		completed	2019	11
A Series of Pilot Studies to Evaluate the haemoDynamic and mEtabolic Effects oF apelIn aNd rElaxin	Phase 2	active not recruiting	2018	170
Serelaxin To Lower Portal Pressure	Phase 2	completed	2017	15
Study of the Effect of Serelaxin on High-sensitivity Cardiac Troponin I (Hs-cTnI) Release in Patients With Chronic Heart Failure	Phase 2	terminated	2016	26
Efficacy, Safety and Tolerability of Sexelaxin When Added to Standard Therapy in AHF	Phase 3	terminated	2014	876
Study of the Vascular Effects of Serelaxin	Phase 2	completed	2014	58
Pharmacokinetics & Safety of Serelaxin on Top of Standard of Care Therapy in Pediatric Patients With Acute Heart Failure	Phase 2	terminated	2014	12
Effect of Serelaxin Versus Standard of Care in Acute Heart Failure (AHF) Patients	Phase 3	terminated	2014	2666
Safety of Repeat Doses of IV Serelaxin in Subjects With Chronic Heart Failure	Phase 2	completed	2014	321
Study of Safety, Tolerability and Pharmacokinetics of Serelaxin in Japanese Acute Heart Failure (AHF) Patients	Phase 2	completed	2014	46
PK of Serelaxin in Severe Renal Impairment and ESRD	Phase 1	completed	2013	36
Efficacy, Safety and Tolerability of Serelaxin When Added to Standard Therapy in AHF	Phase 3	completed	2013	6600
An Exploratory Haemodynamic Study in Patients With Compensated Cirrhosis and Portal Hypertension	Phase 2	completed	2013	47
Safety and Efficacy of RLX030 in Pregnant Women With Pre- Eclampsia	Phase 2	terminated	2013	3
Renal Hemodynamic Effects of RLX030A in Subjects With Chronic Heart Failure (CHF)	Phase 2	completed	2012	118
Hemodynamic Responses to RLX030 Infusion in Subjects With Acute Heart Failure	Phase 2	completed	2012	71
Efficacy and Safety of Relaxin for the Treatment of Acute Heart Failure	Phase 2/Phase 3	completed	2007	1161
Recombinant Human Relaxin for the Treatment of Decompensated CHF	Phase 2	terminated	2006	11
Evaluation of the Safety of Relaxin in Preeclampsia	Phase 1	suspended	2006	18
Recombinant Human Relaxin (rhRlx) in Pregnant Women Scheduled for Induction of Labor	Phase 2	completed	2005	72
A Pilot Study of Recombinant Human Relaxin (rhRlx) in Compensated Congestive Heart Failure	Phase 2	completed	2005	18
Recombinant Human Relaxin in the Treatment of Diffuse Scleroderma	Phase 3	completed	1998	231
Phase II Study of Recombinant Relaxin for Progressive Systemic Sclerosis	Phase 2	completed	1991	1

Peer-reviewed studies (86)

Paper	Authors	Journal	Year	Type
Phase 2b trial of an oral relaxin family peptide receptor 1 agonist in patients with chronic heart failure: rationale and design	Quintana-Hayashi MP et al.	ESC heart failure	2026	Randomized Controlled Trial
Impact of Mild and Moderate Aortic Stenosis in Acute Heart Failure: Insights From RELAX-AHF-2	Venema CS et al.	Journal of cardiac failure	2026	Randomized Controlled Trial
Re-PERFUSE: Phase 1b study of AZD3427, a novel relaxin receptor agonist, on renal perfusion in HFrEF patients	Ufnal M et al.	ESC heart failure	2025	Randomized Controlled Trial
Effects of volenrelaxin in worsening heart failure with preserved ejection fraction: a phase 2 randomized trial	Borlaug BA et al.	Nature medicine	2025	Randomized Controlled Trial
Clinical Presentation, Biomarker Trajectories, and Outcomes in Women and Men Hospitalized for Acute Heart Failure	Ravera A et al.	JACC. Heart failure	2025	Randomized Controlled Trial
Relaxin mimetic in pulmonary hypertension associated with left heart disease: Design and rationale of Re-PHIRE	Ufnal M et al.	ESC heart failure	2025	Clinical Study
End-organ protective effect of serelaxin in patients hospitalized for heart failure: Results of the biomarker substudy of Relaxin in Acute Heart Failure-2 (RELAX-AHF-2)	Voors AA et al.	European journal of heart failure	2025	Randomized Controlled Trial
Decongestion and Outcomes in Patients Hospitalized for Acute Heart Failure: Insights From the RELAX-AHF-2 Trial	Pagnesi M et al.	JACC. Heart failure	2025	Randomized Controlled Trial
Impact of age on clinical outcomes and response to serelaxin in patients with acute heart failure: An analysis from the RELAX-AHF-2 trial	Inciardi RM et al.	European journal of heart failure	2024	Randomized Controlled Trial
Novel Relaxin Receptor RXFP1 Agonist AZD3427 in the Treatment of Heart Failure: A Phase 1a/b, First-in-Human, Randomized, Single-Blind, Placebo-Controlled Study	Connolly K et al.	Journal of the American Heart Association	2024	Randomized Controlled Trial
Distinct Comorbidity Clusters in Patients With Acute Heart Failure: Data From RELAX-AHF-2	Gomez KA et al.	JACC. Heart failure	2024	Randomized Controlled Trial
Volenrelaxin (LY3540378) increases renal plasma flow: a randomized Phase 1 trial	Tham LS et al.	Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association	2024	Randomized Controlled Trial
Factors involved in changes in the levator ani during pregnancy	Martínez Franco E et al.	International urogynecology journal	2023	Observational Study
Neutrophil-to-Lymphocyte Ratio and Outcomes in Patients Admitted for Acute Heart Failure (As Seen in the BLAST-AHF, Pre-RELAX-AHF, and RELAX-AHF Studies)	Davison BA et al.	The American journal of cardiology	2022	Clinical Trial
Vascular effects of serelaxin in patients with stable coronary artery disease: a randomized placebo-controlled trial	Corcoran D et al.	Cardiovascular research	2021	Randomized Controlled Trial
Cause of Death in Patients With Acute Heart Failure: Insights From RELAX-AHF-2	Loungani RS et al.	JACC. Heart failure	2020	Randomized Controlled Trial
A phase 2 randomised controlled trial of serelaxin to lower portal pressure in cirrhosis (STOPP)	Gifford FJ et al.	Trials	2020	Randomized Controlled Trial
Effects of Serelaxin in Patients with Acute Heart Failure	Metra M et al.	The New England journal of medicine	2019	Randomized Controlled Trial
Serum relaxin level predicts recurrence of atrial fibrillation after radiofrequency catheter ablation	Qu X et al.	Heart and vessels	2019	Observational Study
Efficacy and safety of serelaxin when added to standard of care in patients with acute heart failure: results from a PROBE study, RELAX-AHF-EU	Maggioni AP et al.	European journal of heart failure	2019	Randomized Controlled Trial
Site enrollment rate, outcomes, and study drug effects in a multicenter trial. Results from RELAX-AHF	Metra M et al.	International journal of cardiology	2018	Randomized Controlled Trial
Effects of serelaxin on the outcome of patients with or without substantial peripheral edema: A subgroup analysis from the RELAX-AHF trial	Gimpelewicz C et al.	American heart journal	2017	Randomized Controlled Trial
Day vs night: Does time of presentation matter in acute heart failure? A secondary analysis from the RELAX-AHF trial	Pang PS et al.	American heart journal	2017	Randomized Controlled Trial
Serelaxin in addition to standard therapy in acute heart failure: rationale and design of the RELAX-AHF-2 study	Teerlink JR et al.	European journal of heart failure	2017	Randomized Controlled Trial
Serelaxin as a potential treatment for renal dysfunction in cirrhosis: Preclinical evaluation and results of a randomized phase 2 trial	Snowdon VK et al.	PLoS medicine	2017	Randomized Controlled Trial
Serelaxin in acute heart failure patients with and without atrial fibrillation: a secondary analysis of the RELAX-AHF trial	Filippatos G et al.	Clinical research in cardiology : official journal of the German Cardiac Society	2017	Randomized Controlled Trial
A multimarker multi-time point-based risk stratification strategy in acute heart failure: results from the RELAX-AHF trial	Demissei BG et al.	European journal of heart failure	2017	Randomized Controlled Trial
Sex differences in early dyspnea relief between men and women hospitalized for acute heart failure: insights from the RELAX-AHF study	Meyer S et al.	Clinical research in cardiology : official journal of the German Cardiac Society	2017	Randomized Controlled Trial
Evaluating the Efficacy, Safety, and Tolerability of Serelaxin When Added to Standard Therapy in Asian Patients With Acute Heart Failure: Design and Rationale of RELAX-AHF-ASIA Trial	Sato N et al.	Journal of cardiac failure	2017	Randomized Controlled Trial
Recombinant human relaxin versus placebo for cervical ripening: a double-blind randomised trial in pregnant women scheduled for induction of labour	Weiss G et al.	BMC pregnancy and childbirth	2016	Randomized Controlled Trial

More cited research

Elevated maternal serum relaxin concentrations throughout pregnancy in singleton gestations after superovulation (1998, human observational)
Elevated serum relaxin levels in multiple pregnancy after menotropin treatment (1985, human observational)
A randomized, double-blind, placebo-controlled trial of relaxin for cervical ripening in post-delivery date pregnancies (None, human RCT)
Chronic Exposure to Cigarette Smoke Affects the Ileum and Colon of Guinea Pigs Differently. Relaxin (RLX-2, Serelaxin) Prevents Most Local Damage (2021, animal)
Relief of loperamide-induced constipation by peptidic and small molecule RXFP4 agonists in mice (2025, animal)
Transcriptomic identification of starfish neuropeptide precursors yields new insights into neuropeptide evolution (2016, animal)

Conditions researched

Related compounds

FAQ

What is Relaxin (Serelaxin)?

A pregnancy hormone that relaxes blood vessels; serelaxin is a recombinant form studied in acute heart failure.

How many registered human trials study Relaxin (Serelaxin)?

The PeptideWhiz trial index lists 28 registered trials for Relaxin (Serelaxin), the most recent from 2027.

How much published research exists on Relaxin (Serelaxin)?

The PeptideWhiz paper index links 86 PubMed papers to Relaxin (Serelaxin); by study type, 114 human and 86 animal studies.

Which conditions is Relaxin (Serelaxin) researched for?

Atherosclerosis, cardiovascular disease & high blood pressure, Concussion, traumatic brain injury & stroke recovery, Endometriosis, Fatty liver & elevated liver enzymes, Female fertility, Heart repair: after heart attack, heart failure & enlarged heart, Insulin resistance, prediabetes & type 2 diabetes, Kidney protection (CKD, diabetic kidney, lupus kidney), Lung health, asthma & COPD, Lymphedema and swelling, Pregnancy and breastfeeding: safety notes, Sleep problems (incl. insomnia on peptides), Swollen feet and ankles.

Research and education only. Not medical advice. No dosing guidance. Data: ClinicalTrials.gov registry and PubMed via the PeptideWhiz index (204,289 studies).

Reported dosing ranges from research