Among the most selective natural mu-opioid agonists known — proposed as an endogenous ligand of the receptor.
Also known as: EM-1
Part of the Neuropeptides & signaling cluster
Overview
Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2) is an endogenous opioid tetrapeptide and one of the most selective natural agonists of the mu-opioid receptor. First described in 1997, it is widely used as a research tool in opioid pharmacology. This page is educational and makes no claim about pain relief or therapeutic use.
Source & context
Biological / chemical source: Mammalian central nervous system (endogenous)
Primary research or clinical context: Endogenous neuropeptide and research tool in opioid pharmacology; not a Health Canada-authorized product
Structure and selectivity
Endomorphin-1 is a C-terminally amidated tetrapeptide, Tyr-Pro-Trp-Phe-NH2, that binds the mu-opioid receptor with high affinity and unusually high selectivity over delta and kappa receptors. Along with endomorphin-2 it has been proposed as a genuine endogenous ligand of the mu receptor, and it is more prevalent in the brain than in the spinal cord.
Research role and limits
As a selective mu agonist, endomorphin-1 is a common probe in laboratory studies of opioid signalling and analgesia in animal models. Native peptides like this are quickly degraded and do not cross the blood-brain barrier well, which is why they remain research tools rather than medicines. This page is educational and does not describe a treatment.
FAQ about Endomorphin-1
What is Endomorphin-1?+
Endomorphin-1 (Tyr-Pro-Trp-Phe-NH2) is an endogenous opioid tetrapeptide and one of the most selective natural agonists of the mu-opioid receptor. First described in 1997, it is widely used as a research tool in opioid pharmacology. This page is educational and makes no claim about pain relief or therapeutic use.
Is Endomorphin-1 an approved medicine?+
Endomorphin-1 is discussed here as a research / educational topic. Endogenous neuropeptide and research tool in opioid pharmacology; not a Health Canada-authorized product. This is not medical advice.
What is the typical length of Endomorphin-1?+
Endomorphin-1 is commonly described as approximately 4 amino acids (Endogenous opioid tetrapeptide).