In this review, we describe the current knowledge of the mechanism behind the physiological effects of steviol glycosides. Steviol glycosides are known for their extreme sweet taste. Several reports have also ascribed other health benefits to these products, but the lack of understanding of the mechanism behind these effects hampers further research. We show that the interaction between steviol glycosides and the TRPM5 ion channel provides an explanation for the anti-diabetic effects steviol glycosides and harbours a promise that these compounds might also be useful for applications beyond their extreme sweet taste. Indeed, recent work shows that steviol glycosides might represent a novel type of insulinotropic medication, and that steviol and steviol glycosides modulate taste sensations independent of their sweet tasting properties.