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Herb library · Herb · Passiflora incarnata

Passionflower

A climbing vine with white and purple flowers, used as a sedative and sold today for anxiety and sleep. A small amount of research suggests it might ease anxiety and lengthen sleep a little; it has not been studied extensively.

Traditional use

Native to the southeastern United States and Central and South America. It was traditionally used as a sedative; Spanish explorers learned of it in the 1500s and brought it to Europe, where it entered folk medicine. Today it is sold for anxiety (including before surgery), sleep problems, stress, ADHD, and pain.

What studies show

  • Limited

    Anxiety: a small amount of research suggests it might reduce anxiety, including before surgery or dental work, but conclusions are not definite.

  • Limited

    Insomnia: a small amount of research suggests it might increase total sleep time in adults; effects on falling asleep and staying asleep are mixed.

  • Insufficient

    ADHD, heart failure, menopause symptoms, fibromyalgia, stress, and other uses: not enough evidence to say.

Be careful of

Cautions

  • InteractionWith anesthesia or other drugs used around surgery it might slow the nervous system too much. Tell your clinician if you take it within 2 weeks of a scheduled surgery.
  • AmountAs a tea it may be safe for up to 7 nights, and a daily extract may be safe for up to 8 weeks. Safety on the skin is unknown.
  • NotePossible side effects: drowsiness, dizziness, and confusion.
  • PregnancyPassionflower should not be used in pregnancy: it may cause uterine contractions. Little is known about breastfeeding.
  • Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.

From the old books

What herbals and dispensaries of the past printed. History, in their words.

“The physiological action of passiflora has not been well-studied. Medicinal doses produce no special physiological impressions, but we have observed even small doses to occasionally provoke emesis”
Harvey Wickes Felter and John Uri Lloyd, King's American Dispensatory (1905), vol. 2, p. 1440. See the page of King's American Dispensatory, vol. 2, p. 1440 (opens in a new tab) · Read the full passage from King's American Dispensatory, vol. 2, p. 1440

Sources

  1. Passionflower: Usefulness and Safety (opens in a new tab) · NCCIH · read September 25, 2026
  2. Passionflower (LiverTox) (opens in a new tab) · NIH · read September 25, 2026

Reviewed September 25, 2026.