Disclosed are: a fractionation product of royal jelly, which still retains a useful physiological activity of royal jelly and has little concerns that an allergic condition may be induced； a method for producing the fractionation product； and use of the fractionation product in various compositions including a food/beverage, an animal feed, a fish bait, a pet food and an external preparation for the skin such as a cosmetic product each containing the fractionation product. Specifically disclosed are: a fractionation product of royal jelly, which comprises 1 part by mass of 10-hydroxy-2-decenoic acid and less than 0.05 part by mass of a protein derived from royal jelly, which has a useful physiological activity of royal jelly, and which has such a property that no allergenicity against the fractionation product is detected by the passive cutaneous anaphylaxis on a rat using a serum from a mouse immunized with such an amount of the fractionation product that 45 µg of 10-hydroxy-2-decenoic acid is contained in the fractionation product； a method for producing the fractionation product； and use of the fractionation product.
