Cardiovascular · Investigational
Serelaxin (Relaxin-2)
No lawful US pathway
01 · Overview
Serelaxin is a recombinant form of human relaxin-2, a vasodilator peptide hormone that contributes to cardiovascular and renal adaptations during pregnancy (PMID 31433919). It acts via the relaxin family peptide receptor 1 (RXFP1), and the therapeutic rationale in acute heart failure was to reduce vascular resistance and cardiac wall stress.
Development for acute heart failure was discontinued after a large phase 3 trial was negative.
02 · Research summary & key findings
In the RELAX-AHF trial (Lancet, 2013), serelaxin improved dyspnea on one of two co-primary measures and was linked to fewer deaths at day 180 as a prespecified additional endpoint, with no effect on rehospitalization (PMID 23141816). The much larger RELAX-AHF-2 trial (New England Journal of Medicine, 2019; 6,545 patients) found no reduction in cardiovascular death at 180 days or in worsening heart failure at day 5 (PMID 31433919). Serelaxin was not approved, and no marketed product exists.
03 · Regulatory status
Serelaxin (Relaxin-2) is in the investigational stage. While preclinical and early-phase data exist, it has not received regulatory approval for clinical use in the United States.
No lawful pathway today
Serelaxin (Relaxin-2) is not FDA-approved and does not currently have a lawful prescription or compounding pathway in the United States, so we do not sell it and will not book a consultation for it. That can change: in 2026 FDA began reviewing several peptides for compounding.
See the 4 FDA-approved compounds in Cardiovascular
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04 · Administration routes
- Intravenous
References
- [1]Serelaxin, recombinant human relaxin-2, for treatment of acute heart failure (RELAX-AHF): a randomised, placebo-controlled trial Lancet, 2013. PMID 23141816
- [2]Effects of Serelaxin in Patients with Acute Heart Failure N Engl J Med, 2019. PMID 31433919
Primary literature
- PubMed: "Serelaxin"
Peer-reviewed literature indexed by the National Library of Medicine.
- ClinicalTrials.gov: "Serelaxin"
Registered interventional and observational studies, including status and phase.
- PubChem: "Serelaxin"
Chemical structure, molecular properties, and bioactivity data.
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