Immepip is a histamine H3 receptor agonist (KI = 0.4 nM in SK-N-MC cell membranes expressing the human receptor). It is selective for histamine H3 over H1 and H2 receptors in CHO cell membranes expressing the guinea pig and human receptors, respectively (Kis = >16 μM for both) but also agonizes H4 receptors (KI = 9 nM in SK-N-MC cell membranes expressing the human receptor). Immepip (5 mg/kg, s.c.) decreases hypothalamic histamine release in anesthetized rats. It decreases flinching in the formalin test in rats when administered at doses of 5 and 30 mg/kg and inhibits formalin-induced paw edema at 30 mg/kg.