1-Oleoyl glycerol is a monoacylglycerol containing oleic acid at the sn-1 position. 1-Oleoyl glycerol (10%), in a formulation with cyclosporin A in propylene glycol, enhances diffusion of cyclosporin A from the donor compartment of a Franz diffusion cell into the stratum corneum, epidermis, and dermis of porcine ear skin, as well as through the skin to the receptor compartment. Mixed micellar systems containing 1-oleoyl glycerol and bile salts increase the apparent permeability coefficient (Papp) and absorption rate of amphotericin B in perfused rat intestine in vivo. Formulations containing 1-oleoyl glycerol have been used as emulsifying agents, food additives, and absorption enhancers.