Generally speaking, side sleepers require the thickest pillows. A side sleeper will find the distance from their head to their mattress surface is larger than it is for back or front sleepers. Many side sleepers also want a pillow which is flexible to allow scrunching or the possibility of their arm coming up under the pillow. St. Geneve's Lajord and Ziegler Polish pillows in firm are our most popular side sleeper pillows, with Tempur-Pedic's aptly named "SidePillow" being another very popular choice. For more "robust" support consider solid latex pillows such as Natura's Ultimate or Organic Latex varieties, both of which offer a ton of support.