I had the two inch memory foam mattress pad. Got it for Xmas in 2005, and slept on it for about 4 months until I developed numbness in my right thigh in April of 2006 (first obvious sensory symptom I had. Was told it was a sprain )

Slept on the memory foam for another month or three until I couldnt stand it anymore. It was like I would get even more numb in areas that didnt seem to have numbness when I would sit or sleep on the mattress pad.

I ended up giving the matress pad away to my boyfriend's roommate when my parents gave their old king sized waterbed to my boyfriend. (rolled up the pad and stuck it in with bedframe when boyfriend and roomates came to collect the bed)

The memory foam even made my fingers numb when I touched it. I thought for the longest time I was allergic to a chemical in the mattress pad (which is pretty much made up of dead dinosaurs aka petroleum based products)

Made my weird hip pain worse to lay on that mattress pad. At first I only had hip pain in my left hip (numbness in the right hip) and I slept pretty much excusively on my left side. It was when the numbness moved onto my right hip and thigh that I couldnt take it anymore and that's when I gave it away.

For my sleeping problems, I now occasionally take amitriptyline. Which I might not take for much longer, since it seems to exacerbate the dry eyes I've been having problems with lately.

Sometimes seems like everything I take for one problem causes me another problem. Ahhh...modern medicine is just wonderful.