It has no effect at all. Because I used two pairs of shoes rotated, I bought two but it was a failure. I feel rather unnecessarily smelled. By the way it was diagnosed that it is not an athlete's foot in the dermatology department. Also, although it is a free size, I think it is too small. Although the shoes are 27 centimeters, even if you put it without cutting it, you can see that the insole is moving forward and backward, right and left during use.