[Problem] to provide a nuclear morphology improving agent, a progesterin accumulation inhibitor, and a skin external preparation having an effect of improving various diseases and symptoms in various tissues in vivo, particularly various symptoms such as nuclear morphology abnormality and photoaging caused by the accumulation of progein in the skin. [Solution] provided are: A nuclear morphology abnormality improving agent containing a fermentation product obtained by fermentation with yeast using barley seeds as a substrate; a progesterin accumulation inhibitor containing the fermentation product; a skin external preparation containing the agent; and use of the fermentation product for improving photoaging caused by nuclear morphology abnormality and/or progein accumulation. Selected drawing: None
