Kava, which comes in the form of extract or beverage, is made from Piper methysticum, a plant that is native to western Pacific Islands. It is commonly used as a sleep aid and an alternative to sleep medication due to its calming effects. In one study, kava reduced stress levels and alleviated insomnia compared to those who took placebo. Kava is especially effective combating anxiety and anxiety-induced insomnia. Because of this, kava is best used by those whose insomnia is side-effect of anxiety.