I used to sleep on my stomach, with the side of my face on a pillow. I noticed my skin was reacting to being on a pillow for 8 hours at night, so I tried to train myself to sleep on my back. I tried putting a pillow under my knees, surrounding myself with pillows, but nothing worked. Finally, I found this pillow and it works for keeping me on my back. I put it on my existing pillow and it works great!