A method for preparing a xanthohumol-rich hop composition. The method includesproviding a solution thatcontains xanthohumol-containing hop substances and effecting precipitation ofnon-xanthohumol hop substances by adjusting both thesalt concentration and pH value of the solution. The xanthohumol-rich hopcomposition prepared by this method can be used fortreating various diseases, e.g., skin disorders, and bacterial infection
