2-AG exhibits CB agonist activity at the CB1 receptor, is an important endogenous monoglyceride species, and is thus considered to be the natural ligand for the CB1 receptor. 2-AG can also be metabolized by COX-2 and PGD, E, F, and I synthases to form PG 2-glyceryl esters. PGF2α-SA is a stable analog of PGF2α 2-glyceryl ester. The biological activity of PGF2α-SA has not yet been determined.