I had heard to let the topper have time to return to intended size when received. I had also read reviews of a smell that it would have that would leave in a few days. Mine quickly bounced back to the full size, and I did not notice any offensive smell at all. We received it one morning, and put it on the bed that night. We have noticed a big difference in aches and pains that we used to have upon awakening. Both my husband and I have some arthritis. It feels different than your old mattress, so it takes a few days to get used to it, but you will be thrilled with the restful nights and how refresed you feel the next morning!