Passion flower has a mild sedative effect that encourages sleep. This property has been well-substantiated in numerous studies on animals and humans. Nervous symptoms and cramps that inhibit sleep are alleviated by ingestion of the herb, and leading quickly to restful uninterrupted and deep sleep. When Spanish explorers first encountered the Indians of Peru and Brazil, they found this plant used in native folk medicine as a sedative. They took it back to Spain, from whence it gradually spread throughout Europe. It was in Europe that the leaves of the plant first found use as a sedative and sleep-inducing substance. Interestingly, its sedative effect was not noted by American until lately.