I am not sure if there's an adjustment period but our backs been hurting more since using it and also, you can't sit on it despite being "firm." You will sink and have to counterbalance to even stay upright lending to more back pain. My Daughters play mat that's on the floor feels more comfortable than the bed. The smell also took 7-10 days to dissipate with 3 fans blowing at it and 2 air filters