The present invention provides a novel SCD inhibitor. An SCD inhibitor containing a compound represented by the formula [I]
wherein ring A is an optionally substituted aromatic ring, ring B is an optionally substituted ring, ring C is an optionally substituted aromatic ring, R is a hydrogen atom, an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, and X is a spacer having 1 to 5 atoms in the main chain, or a salt thereof, or a prodrug thereof.