You are supposed to change your pillow on a regular basis to avoid mites or other allergens. That being said, these pillows are nice and comfortable for about six months. Then they start to clump up. As an asthma sufferer, these are really nice since I can't sleep on down pillows anymore. It feels like a waste to be replacing them so often, but I've been recycling mine into dog beds so that works out. The price is right so it's all worth it.