A method of preparing a chicory extract enriched with sesquiterpene lactones is provided. The method includes performing an initial extraction chicory in a polar solvent, such as methanol or ethanol, at ambient temperature to form an alcoholic extract. The alcoholic extract is subsequently defatted with a non-polar solvent, preferably hexane or n-heptane. A second extraction of the defatted alcoholic extract is performed with a solvent which is more polar than the solvent used in the defatting process and less polar than the solvent used in the initial extraction, for example, it can be chosen from the group consisting of ethyl acetate, n-butanol, isopropanol, n-propanol, dichloromethane, acetonitrile, and mixtures thereof; resulting in a sesquiterpene lactones enriched extract, preferably containing at least 60% sesquiterpene lactones.