Yes, the coffee grounds can help you reduce the dark circles under the eyes. As we know, the dark circles under the eyes may be caused by the stay up late, not good sleep or the bad blood circulation. While the coffee grounds have the role of resistance to oxidation, increase the intestinal and stomach digestion and so on. Thus, once you get the well digestion which may directly cause your blood move in a fluent way. Then your vital energy and blood will work well. To some degree, the black sediment under the eye skin will be removed. The dark circles under the eyes will be reduced. However, there is another role of the coffee grounds. You could put them in the refrigerator which will help you remove the peculiar smell which you could have a try.