GDF15 and obesity due to melanocortin 4 receptor deficiency: Indeed, GDF15 analogs, which try to overcome the pharmacokinetic (e.g., a short half-life of ~3 h in mice and non-human primates) and physicochemical (e.g., high aggregation propensity) limitations of native GDF15 [1,6,7], have been developed for the treatment of obesity.