I have used these pillows for the past 30 years or so, and they last for about 10 years before you need to replace them. They are hard to find. JC Penney used to carry them but they cost quite a bit more than Overstock lists them for. I am a side sleeper and this is the most comfortable pillow I have ever used. It retains it's shape forever........just becomes less supportive after many years of use so needs replacement. Excellent value and excellent product!