LOVE this mattress pad! I was debating buying a whole new mattress but decided to try this as a last resort and was so pleasantly surprised! It was fully expanded as soon as I took it out of the packaging but I still put it on my floor to flatten out the folds and after about 20 minutes I put it on my bed. I prefer a soft mattress while my boyfriend likes a more firm bed, this works perfect for both of us. I was waking up every morning (or several times a night) with horrible shoulder pain and this pad has changed my life. Cannot recommend this enough, if you are looking for something to completely change your mattress and sleep quality for a low price, BUY THIS!