Selepressin
A cleaner vasopressor that worked on blood pressure but not on outcomes
Selepressin is a synthetic version of vasopressin designed to act only on the V1A receptors that tighten blood vessels. In septic shock it reduced the norepinephrine patients needed, but a large adaptive trial found no improvement in how quickly people came off ventilators and vasopressors, and it was stopped.
What is it?
Septic shock is low blood pressure from infection that persists despite fluids. Norepinephrine is the standard vasopressor, but high doses carry risks, so doctors add vasopressin. Vasopressin acts on several receptors; selepressin was designed to hit only V1A, the one that constricts vessels, in the hope of the benefit without the side effects.
In a 53-patient phase 2a trial, the 2.5 ng/kg/min infusion let about half of patients keep their blood pressure up without norepinephrine at 12 hours and 70% at 24 hours, and cut cumulative norepinephrine sharply.
The definitive test was SEPSIS-ACT, an adaptive phase 2b/3 trial. Among 828 treated patients, ventilator- and vasopressor-free days were 15.0 with selepressin and 14.5 with placebo, 90-day mortality 40.6% and 39.4%, and the trial was stopped for futility.
At a Glance
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Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Published Research
Studies whose titles name selepressin, read from their PubMed abstracts on October 4, 2026.
SEPSIS-ACT trial
828 patients with septic shock received one of three selepressin regimens or placebo; ventilator- and vasopressor-free days were 15.0 vs 14.5 (not significant), 90-day mortality 40.6% vs 39.4%, and the trial stopped for futility. Arrhythmias (27.9% vs 25.2%) and ischaemic events were similar.
Phase 2a: replacing norepinephrine
In 53 patients in early septic shock, selepressin 2.5 ng/kg/min maintained blood pressure without norepinephrine in about half at 12 hours and 70% at 24 hours; 7-day norepinephrine doses were 249 against 761 µg/kg with placebo, and fluid balance was lower from day 5.
The adaptive trial design
Describes the Bayesian adaptive phase 2b/3 design used to choose a dose and then test it against placebo in adults with septic shock, the design SEPSIS-ACT followed.
Endothelial leak
In human lung microvascular endothelial cells, selepressin protected against barrier breakdown caused by thrombin, VEGF, angiopoietin-2 and bacterial lipopolysaccharide.
Gut blood flow in endotoxaemic rats
A safety-pharmacology study in rats with endotoxaemia examined selepressin's effects on mesenteric blood flow and gastric mucosal perfusion, a concern with any vasoconstrictor.
Side Effects & Contraindications
Reported Side Effects
From the SEPSIS-ACT trial, against placebo.
Contraindications & Cautions
Never approved.
Legal Status
Never approved anywhere.
Frequently Asked Questions
?What is selepressin?
A synthetic vasopressin analogue that acts selectively on V1A receptors to raise blood pressure, tested in septic shock.
?Did selepressin work in septic shock?
It reduced norepinephrine needs in a phase 2a trial, but the 828-patient SEPSIS-ACT trial found no improvement in ventilator- and vasopressor-free days or mortality and was stopped for futility.
?How is it different from vasopressin?
Vasopressin acts on several receptors, including V2 in the kidney; selepressin was designed to act only on V1A, which constricts blood vessels.
?Is selepressin approved?
No. It was never approved and development stopped after SEPSIS-ACT.
References
- [other] PubChem CID 53330936, Selepressin: formula C46H73N13O11S2, molecular weight 1048.3. Read October 4, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/53330936
- [clinical-trial] Laterre PF, et al. "Effect of Selepressin vs Placebo on Ventilator- and Vasopressor-Free Days in Patients With Septic Shock: The SEPSIS-ACT Randomized Clinical Trial." JAMA, 2019;322(15):1476-1485. PMID: 31577035.
- [clinical-trial] Russell JA, et al. "Selepressin, a novel selective vasopressin V(1A) agonist, is an effective substitute for norepinephrine in a phase IIa randomized, placebo-controlled trial in septic shock patients." Crit Care, 2017;21(1):213. PMID: 28807037.
- [pubmed] Lewis RJ, et al. "Rationale and Design of an Adaptive Phase 2b/3 Clinical Trial of Selepressin for Adults in Septic Shock. Selepressin Evaluation Programme for Sepsis-induced Shock-Adaptive Clinical Trial." Ann Am Thorac Soc, 2018;15(2):250-257. PMID: 29388815.
- [pubmed] Barabutis N, et al. "Protective Mechanism of the Selective Vasopressin V(1A) Receptor Agonist Selepressin against Endothelial Barrier Dysfunction." J Pharmacol Exp Ther, 2020;375(2):286-295. PMID: 32943478.
- [pubmed] Milano SP, et al. "Selepressin, a novel selective V(1A) receptor agonist: Effect on mesenteric flow and gastric mucosa perfusion in the endotoxemic rabbit." Peptides, 2020;129:170318. PMID: 32330539.
Sources & Citations
Studies from their PubMed abstracts, October 4, 2026.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Consult a licensed healthcare provider before making health decisions.