8-iso Prostaglandin F2α-d 9 is the deuterium labeled 8-Isoprostaglandin F2α. 8-Isoprostaglandin F2α is an isoprostane produced by the non-enzymatic peroxidation of arachidonic acid in membrane phospholipids. 8-Isoprostaglandin F2α is present in human plasma in two distinct forms - esterified in phospholipids and as the free acid. 8-Isoprostaglandin F2α is a weak TP receptor agonist in vascular smooth muscle.