for oral administration for example the form may be a tablet a pill a hard capsule a soft capsule a microcapsule a powder a granule a liquid or the like when produced as medicine the composition of the present invention may be produced in a unit dose required for commonly approved drug administration by for example including a pharmaceutically approved material such as a carrier an excipient a filler an antiseptic a stabilizer a binder a ph modifier a buffer a thickener a gellant a preservative and an antioxidant accordingly as needed the composition of the present invention may also be used as a material for food and beverage or a material for animal feed for example the composition of the present invention or the peptide ile pro pro the peptide leu pro pro or the peptide ser pro pro which is the active ingredient of the composition of the present invention may be considered a functional food such as a food for specified health use which is effective in improving brain function the dose of administration or ingestion of the present composition the peptide ile pro pro the peptide leu pro pro or the peptide ser pro pro in order obtain desired effects is preferably 0 1 mg kg weight to 10 mg kg weight per administration or ingestion in general in terms of the amount of the peptide ile pro pro the peptide leu pro pro or the peptide ser pro pro which is the active ingredient the dose per ingestion in a food which is for example a functional food may also be lowered further than the above described level depending on the number of ingestions.