The present invention relates to: a muscular atrophy-inducing agent containing, as an active ingredient, a hypometabolism-inducing substance selected from the group consisting of 3-iodothyronamine (T1AM), [D-Ala2,D-Leu5] enkephalin (DADLE), 5′-adenosine monophosphate (5′-AMP), and hydrogen sulfide (H2S) a method for preparing a muscular atrophy study model comprising inducing muscular atrophy by administering the muscular atrophy-inducing agent a study model prepared by the method a screening method for a drug for preventing or treating muscular atrophy using the same a composition for preventing or treating muscular hypertrophy and a composition for facial muscle shrinkage. The muscular atrophy study model according to the present invention can provide a study model for an economic muscular atrophy study by using a hypometabolism-inducing substance which can be mass-produced, has an effect which may be usefully used by verification for screening of a drug for preventing or treating muscular atrophy, and can be usefully used as a compositions for preventing or treating muscular hypertrophy and a composition for facial muscle shrinkage through the muscular atrophy effect.
