Following your FUE hair transplant, the best sleep position is on your back, with your head elevated. Consider sleeping on a pillow with a second travel pillow around your neck to keep your head propped up. This position not only helps reduce swelling but also prevents the transplanted areas from touching your pillow and damaging the grafts during sleep.
After 10 days, you are free to sleep in any position, including on your back, sides, or stomach.