PDC31 (THG113.31; ILGHXDYK) is a D-amino acid-based oligopeptide that acts as an allosteric and non-competitive inhibitor of the FP Prostaglandin Receptor, used primarily as a smooth muscle contractile agent. It effectively reduces the strength and duration of uterine contractions in vivo, offering potential for preterm labor and primary dysmenorrhea (PD) research. Additionally, PDC31 enhances the Ca2+-dependent large-conductance K+-channel in human myometrial cells [1] [2].