Passiflora has a long history of use in European and American herbal medicine as a sedative-like remedy for anxiety, insomnia and general nervous disorders. According to the University of Maryland website (UMM), passiflora's traditional use as a calming medication may have some scientific support; however, studies that show passiflora to be an effective medication for the treatment of anxiety combine it with other calming herbs such as valerian and kava.
Passiflora incarnata is the variety of passion flower traditionally harvested for medicinal purposes. The hardy vine grows up to 32 feet long, but is otherwise considered unremarkable. It is the blossom, the flower of the passion flower, that attracts both gardeners and butterflies to this plant. The five petals of the flower bloom in white, but the extravagant sepals create a brilliant show in shades of blue, lavender and magenta. Passiflora bears an egg-shaped fruit that ripens to purple or yellow. The flowers, stems and leaves are dried for tea and infusions or harvested fresh to make extracts and tinctures.
Information published by UMM reports that scientists theorize passiflora works by increasing the levels of gamma-aminobutyric acid (GABA) in the brain. Higher levels of GABA are known to slow brain activity and encourage relaxation. Another theory is that passiflora contains water-soluble pigments, or flavonoids, that produce a calming effect when ingested.
The website Medicine Net reports that people with allergies may experience dizziness or drowsiness when taking passiflora. Because many passiflora preparations contain sugar or alcohol, those with diabetes, liver disease or alcohol dependence are cautioned against using passiflora. Pregnant and nursing women and children should not use passiflora remedies. General side effects include drowsiness, rash and dizziness. Discontinue use immediately if you experience any of these symptoms while taking passiflora. Because of passiflora's sedative effects, consult your health care professional before using any passiflora remedies if you are currently taking other herbal or pharmaceutical medications.