PROBLEM TO BE SOLVED: To provide a body odor inhibitor, capable of effectively suppressing the body odor, particularly the acid odor of the axillary region, and to provide a diketone reaction inhibitor capable of effectively inhibiting the reaction of diketone compound caused by skin components.SOLUTION: The invention relates to a body odor inhibitor for inhibiting the acid odor of the axillary region, which contains at least one kind of extract selected from the group consisting of Mallotus philippinensis extract and Cinchona extract, and to a diketone reaction inhibitor which contains the extract, the diketone reaction inhibitor inhibiting the reaction of a diketone compound represented by a general formula (I): R-(CO)-(CO)-R(where, Rand Reach independently represent an alkyl group with a carbon number 1-4).SELECTED DRAWING: None
