Even though the pharmaceutical industry appears to have largely withdrawn its interest in pursuing the H3R as an anti-obesity target (189), work endures to optimize H3R ligands and explore their potential to influence food intake and body weight, and H3R antagonists/inverse agonists continue to be proposed for the treatment of obesity (190, 191). Here, HRH3 is linked to obesity due to melanocortin 4 receptor deficiency.