For instance, betahistine (a potent H1 and H3 agonist) has been combined with APDs (olanzapine/clozapine) and has been found to reduce APD-induced food intake and obesity both in rodents and humans through the H1R-NPY and the H1R-pAMPKα pathways (65–67). Here, HRH1 is linked to obesity due to melanocortin 4 receptor deficiency.