The invention provides an antiobesity agent advantaged by no worry of side effect, safety and excellent fat accumulation inhibiting effect, and provides pharmaceuticals, food, or cosmetics advantaged by no worry of side effect, safety and excellent fat accumulation inhibiting effect. The invention concretely comprises: an antiobesity agent comprising Rhinacanthus nasutus D represented by the following formula (1), an antiobesity agent comprising a novel compound A represented by the following formula (2), and pharmaceuticals, food, or cosmetics comprising the antiobesity agents and provided with fat accumulation inhibiting effect.
