(+)-Cloprostenol is a synthetic analog of prostaglandin F (PGF). It is an FP receptor agonist and a potent luteolytic agent in rats and hamsters. (+)-Cloprostenol is the optically active, 15(R) enantiomer of cloprostenol responsible for the majority of its biological activity. It is 200 times more potent than PGF in terminating pregnancy when given subcutaneously at a daily dose of 0.125 μg/kg in rats and hamsters, without the side effects associated with PGF (+)-Cloprostenol was also shown to be a potent inhibitor of rat adipose precursor differentiation in primary cultures with an IC value of 3 x 10-12 M. (+)-Cloprostenol isopropyl ester is a more lipid soluble form of cloprostenol.