I applied the included Reedle Shot serum to my entire face, then applied the hydrogel sheet mask. It's Reedle Shot 100, so it tingles a little, but it's not too painful, so it's not bad to use. The hydrogel sheet is cool and comfortable, and after the mask, I felt fresh, moisturized, and one tone brighter. It didn't feel sticky on the surface of my skin, and the skincare products I used afterwards absorbed well. I could feel my skin becoming moisturized, firm, and radiant.