Research compounds
Serelaxin
Recombinant human relaxin-2, RLX030
Serelaxin is recombinant human relaxin-2, a peptide hormone of pregnancy investigated for acute heart failure. Its Phase 3 programme failed, and it is not approved.
Also known as: RLX030, recombinant relaxin, relaxin-2, Reasanz
- Status
- Serelaxin is a research compound and not approved by the FDA for human use.
- Evidence
- Human trials. Published clinical trials in people report results.
- Half-life
- Approximately 5 to 8 hours.
- How it's taken
- Continuous intravenous infusion in the trial setting
- Mechanism
- Other
How Serelaxin works
Relaxin-2 rises markedly in pregnancy and mediates the systemic vasodilation, increased cardiac output and increased renal blood flow that pregnancy requires. It signals through the RXFP1 receptor, producing nitric oxide-mediated vasodilation and anti-fibrotic effects. The rationale in acute heart failure was to reproduce that haemodynamic adaptation — vasodilation with preserved renal perfusion, which conventional vasodilators do not achieve.
What research has looked at
- The Phase 2 RELAX-AHF trial reported improvement in dyspnoea and, unexpectedly, a reduction in 180-day mortality, which generated substantial interest.
- Its anti-fibrotic activity has been investigated separately in fibrotic disease.
- The physiological rationale is unusually clean: it reproduces a naturally occurring adaptive haemodynamic state rather than blocking a pathway.
Evidence level: Human trials. Published clinical trials in people report results. These are areas studied or reported, not promised effects.
Reported side effects and risks
- RELAX-AHF-2, the large confirmatory Phase 3 trial, did not meet its primary endpoints for cardiovascular death or worsening heart failure. This is the decisive fact about the compound, and it is a textbook case of a promising Phase 2 mortality signal failing to replicate.
- Development for acute heart failure was discontinued and no regulator has approved it.
- Hypotension, following from its vasodilator mechanism.
- Anaemia and renal impairment were reported in trials.
- Material sold as relaxin is research chemical supply with unverified identity, purity and dose accuracy.
Sources
- PubMed research on serelaxin RELAX-AHF-2 acute heart failure · NIH · National Library of Medicine
- DrugBank record for serelaxin · DrugBank
- Active clinical trials for serelaxin · U.S. National Library of Medicine
Track Serelaxin in Peptide Vault
Log every dose, set reminders on your own schedule, rotate injection sites and keep your vials organized. Peptide Vault records what you enter. It doesn't recommend compounds or doses. iPhone, on-device.
Related compounds
Serelaxin FAQ
What is Serelaxin?
Serelaxin is recombinant human relaxin-2, a peptide hormone of pregnancy investigated for acute heart failure. Its Phase 3 programme failed, and it is not approved.
How does Serelaxin work?
Relaxin-2 rises markedly in pregnancy and mediates the systemic vasodilation, increased cardiac output and increased renal blood flow that pregnancy requires. It signals through the RXFP1 receptor, producing nitric oxide-mediated vasodilation and anti-fibrotic effects. The rationale in acute heart failure was to reproduce that haemodynamic adaptation — vasodilation with preserved renal perfusion, which conventional vasodilators do not achieve.
Is Serelaxin FDA approved?
No. Serelaxin is a research compound and not approved by the FDA for human use. Evidence level: human trials. Published clinical trials in people report results.
What is the half-life of Serelaxin?
Reported half-life: Approximately 5 to 8 hours.
How is Serelaxin taken?
Continuous intravenous infusion in the trial setting.
What side effects have been reported with Serelaxin?
Reported in the sources: RELAX-AHF-2, the large confirmatory Phase 3 trial, did not meet its primary endpoints for cardiovascular death or worsening heart failure. This is the decisive fact about the compound, and it is a textbook case of a promising Phase 2 mortality signal failing to replicate; Development for acute heart failure was discontinued and no regulator has approved it; Hypotension, following from its vasodilator mechanism; Anaemia and renal impairment were reported in trials; Material sold as relaxin is research chemical supply with unverified identity, purity and dose accuracy.
Educational summary compiled from the sources listed above. Not medical advice. Peptide Vault does not sell, source or recommend any compound. Talk to a qualified clinician before starting or changing anything.