PROBLEM TO BE SOLVED: To provide a drug, a quasi-drug, a dermatological preparation for external use, and a material to be combined with drugs, quasi-drugs, dermatological preparations for external use, or foodstuff which have an excellent UCP-1 expression-promoting action and promote the conversion of fat to brown fat (browning).SOLUTION: Provided is a UCP-1 expression promoter obtained by combining a PPAR-γ activator, a Smad3 inhibitor, and either a &bgr;3-adrenergic receptor activator or a TGR5 activator.SELECTED DRAWING: None【課題】優れたUCP-1発現促進作用を有し、脂肪の褐色脂肪化(褐色化)促進させる医薬品、医薬部外品、皮膚外用剤、若しくは医薬品、医薬部外品、皮膚外用剤又は食品等へ配合する素材の提供。【解決手段】PPARγ活性化剤と、Smad3阻害剤と、β3アドレナリン受容体活性化剤又はTGR5活性化剤とを組み合わせてなるUCP-1発現促進剤。【選択図】なし