The passionflower vine is a native of the Western hemisphere, named for symbolic connections drawn between its appearance and the crucifixion of Jesus. Native North Americans used passionflower primarily as a mild sedative. It quickly caught on as a folk remedy in Europe and was thereafter adopted by professional herbalists as a sedative and digestive aid.

In 1985, Germany's Commission E officially approved passionflower as a treatment for "nervous unrest." The herb is considered to be a mildly effective treatment for anxiety and insomnia, less potent than kava and valerian, but nonetheless useful. Like melissa (lemon balm), chamomile, and valerian, passionflower is also used for nervous stomach.

However, there is only weak supporting scientific evidence that passionflower works for these purposes. Preliminary trials suggest that passionflower might be helpful for anxiety9,14 and chemical dependency.10Animal studiessuggest that passionflower extracts can reduce agitation and prolong sleep.1,11-13

The active ingredients in passionflower are not known.