According to theory, "sin taxes" are welfare improving if consumers with low self-control respond at least as much to the tax as consumers with high self-control. We investigate empirically if demand response to soft drink and fat tax variations in Denmark depends on consumers' self-control. We use a unique home-scan panel that includes a survey measure of self-control. When taxes increase, consumers with low self-control reduce purchases less strongly than consumers with high self-control. When taxes decrease, both groups increase their purchases similarly. The results show an asymmetry in price elasticities by self-control that is more pronounced when taxes increase.