As I mentioned in a studio have a IPL treatment behind me who also went well, I, however, for reasons of cost switch now to a "home unit", I know that the treatment is carried out only with gel in the studio. So I have ordered me to and it works well or as good as in the studio. The light is passed through the gel better in the hair root, the treatment is therefore more effective than without gel. Comparable in consistency with Ultrasound: transparent and slightly viscous and slightly cooling. Price totally OK