Cardiogenol C hydrochloride is a potent cell-permeable pyrimidine inducer which prompts the differentiation of ESCs into cardiomyocytes (EC50=100 nM). Cardiogenol C hydrochloride also acts cardiomyogenic on already lineage-committed progenitor cell types with a limited degree of plasticity. Cardiogenol C hydrochloride is a useful cardiomyogenic agent and can be used as a tool to improve cardiac repair by cell transplantation therapy in animal models.