Home > Catalog Peptides > Endomorphins

If you find Creative Peptides is useful to satisfy your needs, please do not hesitate to contact us!


Browse products name by alphabetical order:

Cat. # Product Name Price
E04002 Endomorphin-2 Inquiry
E04001 Endomorphin-1 Inquiry


In 1997, American scientist ZADINA et al. discovered a highly selective, high-affinity ligand for endogenous morphine called μ opioid receptor and named it endomorphins (EMs). There are two EMs amino acid residue sequences, each named EM-1 and EM-2. The residues of EMs play different functions. The N-terminal amino acid sequence (Tyr and Trp) functions as a recognition receptor, and the pro residue plays an important role in the conformation and enzymatic stability of EMs. The sequence (Phe-NH2) of C-terminal stabilizes the biological activity of the peptide chain by affecting the sequence of the information. Studies have shown that C-terminal modification plays an important role in regulating opioid affinity and pharmacological activity. EMs act highly selectively on μ opioid receptors and play an important role in the body’s analgesic, feeding behavior, gastrointestinal motility, and inflammatory response. EMs also play an important role in cardiovascular aspects.

Mechanism of action

EMs produce a dose-dependent naloxone-sensitive hypotensive effect, and administration of atropine and severing of the bilateral vagus nerves attenuates the EM hypotensive response. The antihypertensive effect of EMs is mediated by opioid receptors, which are involved in central M receptors and are caused by excitatory vagus nerves. The effect of reducing arterial pressure and dilating mesenteric arterioles by EMs is related to the release of NO by vascular endothelial cells by reducing peripheral resistance. EMs can increase K+ permeability on the vascular smooth muscle cell membrane, cause K+ efflux or inhibit Ca2+ influx, lead to hyperpolarization, reduce vasoconstrictive activity, and lower blood pressure.

Application of Endomorphins

EMs have a significant role in inhibiting cardiovascular activity, and studies have shown that EMs can regulate cardiovascular function through both central and peripheral pathways. In addition, EMs analogs can significantly increase the vasodilation response in the rat aortic annulus. In myocardial ischemia-reperfusion injury, EMs may exert certain protective effects through mechanisms such as anti-oxidative stress and anti-inflammatory reaction. A new opioid analgesic with small adverse cardiovascular reactions can be developed through structural modification of EMs. It is expected that EMs analogs will become new drugs for the clinical treatment of cardiovascular diseases such as hypertension and ischemic cardiomyopathy.

1. Bodnar, R. J. (2017). Endogenous opiates and behavior: 2015. Peptides, 88, 126-188.
2. De Marco, R, & Janecka, A. (2015). Strategies to improve bioavailability and in vivo efficacy of the endogenous opioid peptides endomorphin-1 and endomorphin-2. Current Topics in Medicinal Chemistry, 16(2), 141-155.

If you have any peptide synthesis requirement in mind, please do not hesitate to contact us at info@creative-peptides.com. We will endeavor to provide highly satisfying products and services.

Useful Tools

Peptide Calculator

Abbreviation List

Peptide Glossary

Follow us on:

Copyright © 2008 - Creative Peptides. All rights reserved.


Address: 45-16 Ramsey Road, Shirley, NY 11967, USA

Tel: 1-631-624-4882

Fax: 1-631-614-7828



Tel: 44-207-097-1828