Endomorphin-2 is an endogenous peptide with extremely high affinity and selectivity for µ-opioid receptors, with Ki values of 0.69, 9233 and 5240 nM for µ, delta and kappa receptors respectively. Endomorphin-2 is one of the two endomorphins and along with endomorphin-1 produces analgesia in animals, but whereas endomorphin-1 is more prevalent in the brain, endomorphin-2 is more prevalent in the spinal cord.
