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Passion Flower


Botanical names:
Passiflora incarnata

Parts Used & Where Grown

Passion flower is a climbing vine renowned for its beautiful white flowers with purple, blue, or pink calyx crown blooms. The plant is native to North, Central, and South America. While primarily tropical, some of its 400 species can grow in colder climates. The mystery of such a beautiful blossom emerging from an unassuming bud has been compared to the Passion of Christ. This inspired the plant’s name, which dates back to the 17th century. The leaves, stems, and flowers are used for medicinal purposes.

What Are Star Ratings?

This supplement has been used in connection with the following health conditions:

Used for Why
2 Stars
Anxiety (Valerian)
100 to 200 mg valerian and 45 to 90 mg passion flower three times a day
A combination of passion flower and valerian has been shown to reduce symptoms in people suffering from anxiety.

Several plants, known as “nervines” (nerve tonics), are used in traditional herbal medicine for people with anxiety, with few reports of toxicity. Most nervines have not been rigorously investigated by scientific means to confirm their efficacy. However, one study found that a combination of the nervines valerian and reduced symptoms in people suffering from anxiety. In a double-blind study, 45 drops per day of an extract of passion flower taken for four weeks was as effective as 30 mg per day of oxazepam (Serax), a medication used for anxiety.

1 Star
Refer to label instructions
Passion flower is commonly recommended by doctors as a mild sedative for those suffering from insomnia or nervous exhaustion.

Combining valerian root with other mildly sedating herbs is common both in Europe and the United States. Chamomile, hops, , lemon balm, American scullcap, and catnip are commonly recommended by doctors. These herbs can also be used alone as mild sedatives for those suffering from insomnia or nervous exhaustion. Chamomile is a particularly good choice for younger children whose insomnia may be related to gastrointestinal upset. Hops and lemon balm are approved by the German government for relieving sleep disturbances. In a double-blind trial, the combination of valerian root and hops was significantly more effective than valerian root alone for treating insomnia.

1 Star
Refer to label instructions
Passion flower has been historically used to relieve pain.

Other herbs that have been historically used to relieve pain (although there are no modern scientific studies yet available) include valerian, , American scullcap, Piscidia erythrina, and crampbark (Viburnum opulus).

Traditional Use (May Not Be Supported by Scientific Studies)

The historical use of passion flower is not dissimilar to its current use as a mild sedative. Medicinal use of the herb did not begin until the late 19th century in the United States. Passion flower was used to treat nervous restlessness and gastrointestinal spasms. In short, the effects of passion flower were believed to be primarily on the nervous system, particularly for anxiety due to mental worry and overwork.1

The effectiveness of passion flower as a treatment for anxiety has been confirmed in a double-blind study. In that study, 45 drops per day of an extract of passion flower taken for four weeks was as effective as 30 mg per day of oxazepam (Serax®), a medication used for anxiety.2

How It Works

Botanical names:
Passiflora incarnata

How It Works

For many years, plant researchers believed that a group of harman alkaloids were the active constituents in passion flower. Recent studies, however, have pointed to the flavonoids in passion flower as the primary constituents responsible for its relaxing and anti-anxiety effects.3 European herbal pharmacopoeias typically recommend passion flower products containing no less than 0.8% total flavonoids. The European literature involving passion flower recommends it primarily for the treatment of mild to moderate anxiety. In this context, it is often combined with valerian, lemon balm, and other herbs with sedative properties.

How to Use It

The recommended intake of the dried herb is 4–8 grams per day.4 To make a tea, 0.5 to 2.5 grams of the herb can be steeped with boiling water for ten to fifteen minutes and drunk two to three times per day. Alternatively, 5–10 ml of passion flower tincture can be taken three to four times per day.


Botanical names:
Passiflora incarnata

Interactions with Supplements, Foods, & Other Compounds

Some practitioners suggest not using passion flower with MAO-inhibiting antidepressant drugs because of concerns that they may interact with the harman alkaloids in passion flower.5 However, this interaction is theoretical and has not been reported in the medical literature.

Interactions with Medicines

As of the last update, we found no reported interactions between this supplement and medicines. It is possible that unknown interactions exist. If you take medication, always discuss the potential risks and benefits of adding a new supplement with your doctor or pharmacist.
The Drug-Nutrient Interactions table may not include every possible interaction. Taking medicines with meals, on an empty stomach, or with alcohol may influence their effects. For details, refer to the manufacturers’ package information as these are not covered in this table. If you take medications, always discuss the potential risks and benefits of adding a supplement with your doctor or pharmacist.

Side Effects

Botanical names:
Passiflora incarnata

Side Effects

Used in the recommended amounts, passion flower is generally safe and has not been found to adversely interact with other sedative drugs. A single case has been reported of a 34-year-old female who developed severe nausea, vomiting, drowsiness, and heart symptoms following self-administration of passion flower. It is not known for certain if passion flower caused her symptoms.6 Passion flower has not been proven to be safe during pregnancy and breast-feeding.


1. Foster S. Herbs for Your Health. Loveland, CO: Interweave Press, 1996, 68-9.

2. Akhondzadeh S, Naghavi HR, Vazirian M, et al. Passionflower in the treatment of generalized anxiety: a pilot double-blind randomized controlled trial with oxazepam. J Clin Pharm Ther 2001;26:363-7.

3. Meier B. Passiflora incarnata L.—Passion flower: Portrait of a medicinal plant. Zeitschrift Phytother 1995;16:115-26.

4. Wichtl M. Herbal Drugs and Phytopharmaceuticals. Boca Raton, FL: CRC Press, 1994, 363-5.

5. Newall CA, Anderson LA, Phillipson JD. Herbal Medicines: A Guide for Health-Care Professionals. London: Pharmaceutical Press, 1996, 206-7.

6. Fisher AA, Purcell P, Le Couteur DG. Toxicity of Passiflora incarnata L. J Toxicol Clin Toxicol 2000;38:63-6.

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How It Works

PeaceHealth endeavors to provide comprehensive health care information, however some topics in this database describe services and procedures not offered by our providers or within our facilities because they do not comply with, nor are they condoned by, the ethics policies of our organization.