Provided is an activator for a peroxisome proliferator-activated receptor α which contains : a compound represented by general formula (I); a tautomer, stereoisomer, or pharmaceutically acceptable salt of said compound; or a solvate of any of these compounds (in the formula, R1, R2, R3, R6, R7, and R8 (provided that R1, R2, R3, and R8 do not form a ring) may be the same or different, and represent a hydrogen atom, a halogen atom, a C1–8 alkyl group, a C1–8 alkoxy group, a C1–8 alkyl group substituted with one to three halogen atoms, a C1–8 alkoxy group substituted with one to three halogen atoms, a hydroxy group, an amino group, a carboxyl group, a mercapto group, a C1–8 alkylsulfanyl group, a nitro group, or a cyano group).