Cyclic peptide agonists toward human galanin receptor 2 (GalR2) and galanin receptor 3 (GalR3) based on hidden conformation of spexin solution structure for GalR2 and GalR3-related and spexin-deficient disorders are designed and synthesized. LH101, LH102, and LH101 (Ac) are potent spexin analogs with prolonged action, which can be used in the treatment of GalR2 and GalR3-related diseases and spexin-deficient disorders, such as obesity.