Formulations for preventing the sexual transmission of the HIV virus are provided. In one embodiment, the formulations contain un-conjugated liposomes whose physicochemical properties allow binding to the HIV virus. The liposomes are made up of natural or synthetic lipids, alone or in combination. Preferably, the liposomes are made entirely of cardiolipin. In other embodiments the liposomes are modified to contain Hgands which bind HIV. The method for preventing the sexual transmission of the HIV virus includes self-administration of a formulation containing an effective amount of liposomes which bind to the HIV virus to the surface of a mucosal membrane prior to intercourse.