A pharmaceutical compound for the treatment of obesity related disorder that is a conjugate of myristic acid and a leptin-related peptide. Preferably, the leptin-related peptide is OB3 that has been D-substituted at Leu-4. The resulting conjugate significantly improved the pharmacokinetic profile of the leptin-related peptide by extending its half-life from less than one hour to as long as twenty-eight hours, depending on the route of delivery, increasing uptake, reducing the rate of plasma clearance, and enabling the minimal effective dose to be reduced several fold.