Endomorphin 2 TFA, a high affinity, highly selective agonist of the μ-opioid receptor, displays reasonable affinities for kappa3 binding sites, with Ki value between 20 and 30 nM[1]. Ki: 20-30 nM (kappa3 opioid receptor)[1]
[1]. Goldberg IE, et al. Pharmacological characterization of endomorphin-1 and endomorphin-2 in mouse brain. J Pharmacol Exp Ther. 1998 Aug;286(2):1007-13.
















