Abstract. Prior research has suggested that circulating levels of glucose in the bloodstream help to determine success at self-control. However, this idea has been challenged on multiple grounds. The current research added new evidence to the debate by testing (1) the extent to which exercising self-control reduces blood glucose levels, (2) whether consuming glucose, rinsing the mouth with glucose, or consuming aspartame (a sugar substitute) increases blood glucose levels, and (3) the extent to which measured blood glucose levels relate to emotional responding, delay discounting, and cognitive control, respectively. We found no evidence that blood glucose levels influence or are influenced by self-control.