Passiflora: Passionflower

by Paul Bergner

Medical Herbalism  7(1&2):13-14,26

Passiflora incarnata is a climbing plant that grows naturally in the tropical and semi-tropical parts of the Americas. It will also grow if planted as far north as Vancouver, British Columbia on the West Coast and Boston on the East. Its intricate and delicate flower gives the clue for its use as a sedative and antispasmodic — it works best in fragile, delicate, and run down constitutions or conditions, and is especially well-suited to pediatric and geriatric use.

Spanish conquerors of Mexico and South America learned its use as a sedative from the Aztec Indians and it eventually became widely cultivated in Europe. It was introduced in the North American medicine in the mid 1800s, possibly reintroduced from Europe, possibly through Native and slave use in the South, and possibly through both of these. Blacks in the deep South used to use poultices of the bruised leaves for headache, bruises, and for pain. A decoction was used in various aches and pains in teaspoon and tablespoon doses (Ellingwood) Either the dried leaves or the dried whole flowering tops are used, depending on the author.

Pharmacology is disputed

The pharmacology of passiflora is not entirely understood, and no single active constituent has been identified. Flavonoids and alkaloids are most often cited as active constituents. The plant contains small amounts of harmala alkaloids, harmane (passaflorine), and possibly harmine (telepathine), harmaline, harmol, and harmalol. The presence of the last four in Passiflora incarnata is disputed (Bennati; Loehdefink and Kating). The importance of whatever harmala alkaloids are present to the therapeutic effect of passiflora is also questionable. They are contained in only very small amounts (0.01 percent or less) (Lawrence Review). Furthermore, they have been identified as stimulants and monoamine oxidase inhibitors (Fernandez de Arriba; Rommelspacher; Ergene), which would give antidepressant rather than sedative effects. Wild rue (Peganum harmala), which contains significant amounts of these substances (and after which they were named), is used therapeutically as a stimulant rather than a sedative (U.S. Dispensatory). These properties of the harmala alkaloids are the source of rumors that passiflora extract acts as a MAO inhibitor. If true this would be a cause for concern because clinical inhibition of MAO — an enzyme involved in brain chemistry and other functions in the body — has serious side effects. That they are probably not involved in the pharmacological effect of passiflora extracts is supported by the fact that they are “practically insoluble in water” (Merck) while water preparations of passiflora are clinically effective for sedation. Some researchers have demonstrated that water soluble constituents are sedative (Fellows and Smith) and others have found sedative effects not related either to the alkaloids or the flavonoids (Speroni and Minghetti). Other researchers demonstrated that an extract containing the alkaloids and the flavonoids together also had a sedative effect (Lutomski). Were the harmala alkaloids the active principle in passiflora, there might also be cause for concern about kidney toxicity, as these substances are toxic to the kidneys (Hagiwara).

The bottom line: researchers don’t know what constituents are responsible for the sedative and antispasmodic effects of passiflora extracts. Don’t let anyone tell you a standardized extract of this one is better, or tell you that it is toxic because of its alkaloids.


Passiflora has a mixed reputation because it is sometimes ineffective. It is my opinion that this is due to ignorance of its indications rather than variability of the plant potency. It is best suited to the weak, fragile, or exhausted patient with insomnia, agitation, and/or spasm or muscular twitching. The exhaustion might come from chronic illness, debilitating fever, over work, worry, old age, etc. but there is always a fragility or exhaustion. Ellingwood says that passiflora is not likely to work if a person has normal strength. The congested patient may also fail to respond. According to Scudder: “From the failures we have had we believe that it does not do well when the tongue is dirty and heavily coated. But when given to a patient, young or old, with a clean tongue, it acts promptly and pleasantly.


Passiflora’s most powerful properties are hypnotic (sleep inducing) and antispasmodic. In insomnia, it does not force sleep, but supports normal sleep, without producing mental dullness or inefficient thinking. Ellingwood says of passiflora: “The sleep produced is normal in all its characteristics. The patient goes to sleep naturally, can be awakened as usual at any time, to fall into a quiet natural slumber. He awakens at the usual time rested and refreshed, with no disturbance of the cerebral functions, no languor, dullness or other disagreeable sensations.” This clinical observation is supported by recent animal trials. In a recent trial in Italy, rats who were given an oral passiflora extract for three weeks had reduced activity from the sedative effects, but the electroencephalogram showed normal electrical activity of the brain (Sopranzi et al). Other animal trials have shown that passiflora reduces pain, prolongs sleeping time, protects against convulsant drugs, and reduces motor activity (Speroni and Minghetti).

It is indicated for restless and wakeful sleep, resulting from exhaustion, in the patient that fits its general picture. In terms of traditional Chinese medicine, it is well-suited to the insomnia of Yin deficiency. Insomnia associated with chronic fatigue syndrome or with drug withdrawal may be benefitted. It is not effective alone for the insomnia of pain, because its anodyne properties are not especially strong. It works well combined with other herbs for pain, such as Jamaican dogwood, cramp bark, or valerian. Because it is an effective antispasmodic (in the patient that matches its indications) it can also help with insomnia due to spasmodic coughs.

Spasm and Convulsion

According to the clinical uses by physicians in the last century, passiflora is a powerful antispasmodic. It was used in severe spasm such as accompanies tetanus, and to abort an epileptic attack Ellingwood says it is effective for “severe spasms even while the irritating causes yet remain.” The Eclectics used it in children for the spasmodic coughing of whooping cough and for spasms accompanying menstrual pain. In treatment for astma with strong signs of spasm in children, the Eclectics gave 10 to 30 drops every ten minutes.

Other uses

Other uses listed in Eclectic literature include “hysteria” (emotional lability) and mania. Passiflora is useful in the manic phase of bipolar disorder, although management with lithium is necessary in serious cases. Passiflora is also indicated for neuralgia and shingles. Its use to lower blood pressure is somewhat controversial. It temporarily reduces the pulse and arterial tension due to effects on cerebral regulation, according to Ellingwood. It does not suppress respiration, however, so it can be given in larger doses without danger. A final indication is fretfulness of teething children.

Passiflora extract were classified “General garded as Safe” by the U.S. Food and Drug Administration. Currently they may not be sold with claims because of lack of proof of efficacy. Specific Medication writer John Fyfe, MD, states: “That passiflora is not toxic is evidenced by the fact that it has been given in 10-15 drop doses every hour for six and eight hours, to infants less than one year old, without the slightest evidence of deleterious effects. It has also been administered to the very sick and weak without harmful action.”


A wide range of doses are recommended for passiflora, so the practitioner will have to tailor the dose to the patient.

- Homeopaths used Passiflora in “large doses of the mother tincture” — thirty-sixty drops repeated several times.

- Ellingwood recommends ten to sixty drops

- Scudder recommends the same dose well-diluted and repeated every hour.

- The German monograph says six grams of the herb per day in infusion

- Priest and Priest suggest a maximum dose of 15 drops

- Ellingwood cites a traditional use of x teaspoon and tablespoon doses of a decoction.

Felter says that passiflora is slow acting, and more effective in second twenty-four hours than in the first twenty-four.


Bennati E (1968) Boll Chim Farm 107:716 [cited in Wren RC Potter’s New Encyclopaedia of Botanical Drugs and Preparations Saffron Walden. 1988]

Ergene E, Schoener EP. “Effects of harmane (1-methyl-beta-carboline) on neurons in the nucleus accumbens of the rat.” Pharmacol Biochem Behav 1993 Apr;44(4):951-7

Fellows and Smith, J A Ph A 1938;27(565) [cited in United States Dispensatory 1947]

Fernandez de Arriba A, Lizcano JM, Balsa MD, Unzeta M. “Inhibition of monoamine oxidase from bovine retina by betacarbolines.” J Pharm Pharmacol 1994 Oct;46(10):809-13

Fyfe, John William MD. Specific Diagnosis and Specific Medication Cincinnati: The Scudder Brothers, 1909

Hagiwara A, Sano M, Asakawa E, Tanaka H, Hasegawa R, Ito N “Enhancing effects of harman and norharman on induction of preneoplastic and neoplastic kidney lesions in rats initiated with N-ethyI-N-hydroxyethylnitrosamine.” Jpn J Cancer Res 1992 Sep;83(9):949-54

Lawrence Review of Natural Products May 1989.

Leohdefink J, Kating H (1974) Planta Med 25:1010 [cited in Wren RC Potter’s New Encyclopaedia of Botanical Drugs and Preparations Saffron Walden. 1988]

Lutomski J, Wrocinski T. 1960 Buil Inst Ros Lec 6:176 [cited in Wren RC Potter’s New Encyclopaedia of Botanical Drugs and Preparations Saffron Walden. 1988]

Merck Index. 11th Ed. (1989) Merck Inc. Rahway, NJ.

Rommelspacher H, May T, Salewski B, “Harman (1- methyl-beta-carboline) is a natural inhibitor of monoamine oxidase type A in rats” Eur J Pharmacol 1994 Jan 24;252(1):51-9

Scudder J. Specific Medication. Eclectic Medical Publications Sopranzi N et al. “Bilogical and electroencephalographic parameters in rats in relation to Passiflora Incarnata L.” Clin Ter 1990;132(5):329-333 [Italian language]

Speroni E, Minghetti A. Neuropharmacological activity of extracts from Passiflora incarnata." Planta Med1988;54(6):488-491

United States Dispensatory JB Lippencott. 1947

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