This mattress is polyurethane just like all of the rest of the "memory foam" mattresses. My husband and I thought we were paying a little more than we planned for a better bed, but we were wrong. It is supportive and we don't wake up with back aches, but it just doesn't have that floating on a cloud feeling like the real memory foam from Tempurpedic for example. The fact that it is 17" deep is also a little frustrating when buying sheets because you have to get those that are extra deep which usually limits your color and quality choices. After about 6 months with this bed, you do start to notice yourselves always rolling toward the center of the mattress, but it's not as bad as our last 2 mattresses that we've slept on. If you are looking for a quality memory foam, go with the brand name, not polyurethane type. I know they are expensive, but it's for a good reason (I would have liked to have had this attitude prior to this purchase because now we are leaving the memory foam idea altogether). Or, if you want something cheap and decent for a few years, go for this type, but in a smaller size like 11" or 14".