To obtain a Maillard reaction inhibitor, comprising a fat-soluble benzophenone derivative.

This medicine comprises a fat-soluble benzophenone derivative or a substance containing the derivative. A polyisoprenylated benzophenone derivative, preferably camboginol is cited as the fat-soluble benzophenone derivative. An organic extract of a plant of the genus Hypericum or its purified substance is used as the substance containing the fat-soluble benzophenone derivative. The Maillard reaction inhibitor is used in 0.00001 to 10w/w%, preferably 0.0001 to 1w/w 5. The inhibitor is strong in activity, fat-soluble, convenient in preparation and excellent in absorption efficiency in organisms, localization efficiency, etc. The inhibitor is effective as a cosmetic base and a preventive and a therapeutic agent for various diseases followed by aging.