The present invention provides a carboxymethylarginine production inhibitor for inhibiting the production of carboxymethylarginine and a collagen denaturation inhibitor for inhibiting the denaturation of collagen, both of which provide excellent safety. The carboxymethylarginine production inhibitor and the collagen denaturation inhibitor according to the present invention contain an extract of at least one plant selected from the group consisting of plants of Compositae Anthemis, Saururaceae Houttuynia, Rosaceae Crataegus, and Vitaceae Vitis. Specifically, they preferably contain an extract of at least one plant selected from the group consisting of Anthemis nobilis L., Houttuynia cordata Thunberg, Crataegus oxyacantha L., and Vitis vinifera L.
