As its name implies, passionflower is a plant. This herb is often used for insomnia. But is also used for generalized anxiety disorder and gastro intestinal issues. It’s mechanism of action in insomnia is likely to be its calming effect.
Dr. Mark Hyman mentions passionflower in this YouTube video.
Medline says that passionflower is “likely safe” for most people when taken orally in amounts found in food. And “possibly safe” when taken short term (such as less than 2 months). And “possibly unsafe” when taken in large amounts.
Passionflower is not suitable for everyone or every condition. Check with your medical profession first. Do not take if you are pregnant and do not take at least 2 weeks before any surgery. And it can interact with other medications, especially with high-blood-pressure medications and sedative medications.