Side-by-Side Comparison · 2026

Big Endothelin-1 vs Urotensin-II

Big Endothelin-1 vs Urotensin-II — mechanism, half-life, dosing, and research status compared. Which is right for your protocol?

Big Endothelin-1
Vasoactive Peptide

Big endothelin-1 (big ET-1) is a 38-amino acid peptide that is the direct precursor to the potent vasoconstrictor endothelin-1 (ET-1). It is produced by vascular endothelial cells from preproendothelin-1 and cleaved to the active 21-amino acid ET-1 by endothelin-converting enzyme...

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Urotensin-II
Vasoactive Peptide

Human Urotensin-II (U-II) is an 11-amino acid cyclic peptide and the most potent mammalian vasoconstrictor identified to date - approximately 10 to 20 times more potent than endothelin-1 in isolated vascular preparations. Originally characterized in fish urophysis (caudal neurose...

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Key Parameters
Parameter Big Endothelin-1 Urotensin-II
Category Vasoactive Peptide Vasoactive Peptide
Research Preclinical/Biomarker Active Research
Half-Life Longer than ET-1 (~plasma half-life 3-5 min ET-1) ~30 minutes (plasma)
Typical Dose Research only 0.01-1 nmol/kg/min IV (animal); picomolar concentrations produce vasoconstriction
Frequency N/A Acute infusion
Route Endogenous; IV (research) IV infusion (research/clinical studies)
FDA Status No approval Research compound; UT receptor antagonists in clinical trials

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Frequently Asked Questions
What is the difference between Big Endothelin-1 and Urotensin-II?
Big Endothelin-1: Big endothelin-1 (big ET-1) is a 38-amino acid peptide that is the direct precursor to the potent vasoconstrictor endothelin-1 (ET-1). It is produced by vascular endothelial cells from preproendotheli... Urotensin-II: Human Urotensin-II (U-II) is an 11-amino acid cyclic peptide and the most potent mammalian vasoconstrictor identified to date - approximately 10 to 20 times more potent than endothelin-1 in isolated v...
Which has a longer half-life, Big Endothelin-1 or Urotensin-II?
Big Endothelin-1 half-life: Longer than ET-1 (~plasma half-life 3-5 min ET-1). Urotensin-II half-life: ~30 minutes (plasma).
Can you stack Big Endothelin-1 and Urotensin-II?
Big Endothelin-1 and Urotensin-II are in the same category and used together in research protocols. Always consult relevant literature and follow appropriate guidelines.

For research use only. Not medical advice. ASCEND does not conduct or endorse any specific research protocol. Always consult relevant scientific literature and regulatory guidelines.