A method of increasing the solubility of a water-insoluble or slightly water- soluble hydrophobic organic compound in an aqueous solvent comprises adding a saponin component selected from the group consisting of escin, glycyrrhizin, and Quillaya saponaria extract to the aqueous solvent in an amount sufficient to trigger the formation of micelles, wherein in a first step the hydrophobic organic compound is pre-dissolved in an organic solvent, whereupon in a second step the organic solvent comprising the pre-dissolved compound is admixed to the aqueous solvent; whereupon at least a part of the insoluble or slightly soluble hydrophobic organic compound gets solubilized and dissolved in the aqueous solvent, yielding an aqueous composition having an increased concentration of said organic compound dissolved therein. The invention also relates to pharmaceutical or cosmetic compositions comprising a water-insoluble or slightly water-soluble organic compound dissolved in an aqueous solvent at substantially increased concentrations.