Passionflower — Passiflora incarnata

Common & Latin Names

Common names: Passionflower, Maypop, Purple passionflower, Wild passion vine, Apricot vine Latin name: Passiflora incarnata L. Spanish: Pasionaria, Flor de la pasion Portuguese: Maracuja (the fruit-bearing species P. edulis shares this common name)

Plant Family & Parts Used

Family: Passifloraceae (passionflower family) Parts used: Aerial parts — leaves, stems, and flowers (harvested during flowering). The whole above-ground herb is used. The fruit of P. incarnata is edible but not the primary medicinal part (P. edulis is the commercial passion fruit). Habitat: Native to the southeastern United States, Central America, and South America. Grows as a vigorous perennial climbing vine in warm, temperate to subtropical climates. Hardy, tenacious plant that colonizes disturbed areas, roadsides, and forest edges. Now widely cultivated in Europe (particularly Italy, where significant research has been conducted) and India.

Traditional Uses

Indigenous American Traditions

Native American peoples of the southeastern United States, including the Cherokee, used passionflower as a sedative, for earaches, as a poultice for wounds and boils, and for liver conditions. The Houma used it for blood purification. The Algonquin used the root for inflammation. The plant’s name was given by Spanish missionaries who saw in its complex flower structure a representation of the Passion of Christ — the corona filaments as the crown of thorns, the five stamens as the five wounds, the three styles as the three nails.

Western Herbalism (19th century onward)

Passionflower entered Western materia medica in the mid-1800s. The Eclectic physicians (notably John King and Harvey Wickes Felter) prescribed it for insomnia, nervous exhaustion, neuralgia, and epilepsy. It became one of the most widely prescribed nervines in American and European herbal practice. In 1978, passionflower was included in the British Herbal Pharmacopoeia for neuralgia and insomnia.

Brazilian and South American Medicine

In Brazilian folk medicine, passionflower (maracuja — though this more commonly refers to P. edulis) is widely used as a calmante (calming agent) for anxiety, insomnia, and nervous agitation. It is one of the most commercially important medicinal plants in Brazil.

Active Compounds & Pharmacology

Primary Phytochemicals

Flavonoids (the primary active group):

• Chrysin: Potent GABA-A receptor modulator with demonstrated anxiolytic activity. Also an aromatase inhibitor (inhibits the conversion of testosterone to estrogen).
• Vitexin and isovitexin: C-glycosyl flavones with anxiolytic, antioxidant, and anti-inflammatory effects.
• Orientin and isoorientin: Antioxidant and neuroprotective flavonoids.
• Apigenin: Anxiolytic GABA-A modulator (also found in chamomile).

Alkaloids (low concentration):

• Harman and harmine: Beta-carboline alkaloids with MAO-A inhibitory activity. Present in very low concentrations in passionflower — likely contributing to mood effects but at safe levels.
• Harmol and harmalol: Related beta-carbolines.

Gamma-aminobutyric acid (GABA): Passionflower contains small amounts of actual GABA, though the contribution of ingested GABA (which crosses the blood-brain barrier poorly in adults) to clinical effects is debated.

Maltol and ethyl-maltol: Contribute to anxiolytic activity.

Mechanisms of Action

1. GABAergic Modulation: The primary mechanism. Chrysin and apigenin bind to GABA-A receptors as positive allosteric modulators — they enhance the effect of endogenous GABA without directly activating the receptor (similar in concept to benzodiazepines but at a different binding site). This produces anxiolysis and sedation without the tolerance, dependence, and cognitive impairment associated with benzodiazepines.

2. MAO Inhibition (Mild): Harman alkaloids provide mild monoamine oxidase inhibition, increasing synaptic serotonin and dopamine. This contributes to antidepressant and mood-stabilizing effects. The concentrations are low enough to avoid the dietary restrictions required with pharmaceutical MAOIs.

3. Endocannabinoid Modulation: Emerging evidence suggests passionflower flavonoids may modulate the endocannabinoid system, potentially contributing to anxiolysis and pain reduction through CB1 receptor pathways.

4. Anti-inflammatory: Flavonoids inhibit NF-kB signaling, reduce COX-2 expression, and modulate inflammatory cytokine production.

Clinical Evidence

Key Clinical Trials

Akhondzadeh, S., Naghavi, H.R., Vazirian, M., et al. (2001). “Passionflower in the treatment of generalized anxiety: a pilot double-blind randomized controlled trial with oxazepam.” Journal of Clinical Pharmacy and Therapeutics, 26(5), 363-367.

• 36 patients with GAD, randomized to passionflower extract 45 drops/day vs oxazepam (a benzodiazepine) 30mg/day for 4 weeks
• Results: Both treatments equally effective in reducing anxiety (HAM-A scores). No significant difference between groups. However, passionflower had significantly LESS impairment of job performance than oxazepam (p=0.01). The benzodiazepine worked faster (onset by day 4 vs day 7 for passionflower) but caused more sedation-related impairment.
• Landmark study: demonstrated that passionflower is comparable to a benzodiazepine for generalized anxiety with a superior side effect profile.

Appel, K., Rose, T., Fiebich, B., et al. (2011). “Modulation of the gamma-aminobutyric acid (GABA) system by Passiflora incarnata L.” Phytotherapy Research, 25(6), 838-843.

• In vitro study demonstrating that passionflower extract modulates GABA-A and GABA-B receptor subtypes
• Identified that the anxiolytic mechanism involves both receptor types
• Also showed inhibition of GABA reuptake — a novel mechanism that increases GABA availability in the synaptic cleft

Ngan, A., & Conduit, R. (2011). “A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality.” Phytotherapy Research, 25(8), 1153-1159.

• 41 participants, passionflower tea (1 cup nightly for 7 days) vs placebo tea in crossover design
• Results: Significant improvement in subjective sleep quality (p=0.049) with passionflower tea compared to placebo. Polysomnography showed no significant objective differences — suggesting passionflower improves the subjective experience of sleep quality rather than altering sleep architecture.

Movafegh, A., Alizadeh, R., Hajimohamadi, F., et al. (2008). “Preoperative oral Passiflora incarnata reduces anxiety before surgery: a randomized, double-blind, placebo-controlled study.” Anesthesia and Analgesia, 106(6), 1728-1732.

• 60 patients scheduled for ambulatory surgery, 500mg passionflower extract vs placebo 90 minutes before surgery
• Results: Significant reduction in anxiety (numeric rating scale, p<0.001) without increased sedation or psychomotor impairment compared to placebo.

Dantas, L.P., de Oliveira-Ribeiro, A., de Almeida-Souza, L.M., & Groppo, F.C. (2017). “Effects of passiflora incarnata and midazolam for control of anxiety in patients undergoing dental extraction.” Medicina Oral, Patologia Oral y Cirugia Bucal, 22(1), e95-e101.

• 40 patients, passionflower 260mg vs midazolam 15mg before dental extraction
• Results: Both treatments reduced anxiety similarly. Passionflower group showed less amnesia than midazolam group.

Therapeutic Applications

Conditions

• Generalized anxiety disorder (primary indication — evidence equivalent to benzodiazepines)
• Insomnia (sleep onset and sleep quality)
• Pre-procedural anxiety (dental, surgical)
• Nervous agitation and restlessness
• Opiate withdrawal (adjunctive — reduces anxiety symptoms)
• ADHD (adjunctive — calms without cognitive impairment)
• Menopausal anxiety and insomnia
• Muscle tension and spasm (GABAergic relaxation)

Dosage Ranges

• Dried herb tea: 1-2g steeped in 150mL hot water for 10-15 minutes, 2-3 cups daily. One cup before bedtime for sleep.
• Tincture (1:5 in 45% alcohol): 1-4mL, 2-3 times daily
• Standardized extract: 250-500mg, 2-3 times daily (standardized to vitexin or total flavonoids)
• Fluid extract (1:1): 0.5-2mL, 2-3 times daily
• Combination formulas: Often combined with valerian, hops, and/or lemon balm for synergistic anxiolytic and sleep effects.

Safety & Contraindications

Excellent Safety Profile

Passionflower is generally recognized as safe (GRAS) by the FDA. European Medicines Agency (EMA) has approved traditional use for relief of mild symptoms of mental stress and as a sleep aid. Adverse events in clinical trials are minimal and comparable to placebo.

Contraindications

• Pregnancy: Uterotonic effects demonstrated in animal studies. Harman alkaloids may have teratogenic potential at high doses. Avoid during pregnancy.
• Lactation: Insufficient safety data for concentrated extracts.
• Pre-surgical: Discontinue 2 weeks before surgery due to potential additive effects with anesthetic agents.
• Children under 6: Insufficient safety data for concentrated extracts (traditional use of weak tea exists).

Drug Interactions

• Sedatives and CNS depressants (benzodiazepines, barbiturates, alcohol, opioids): Additive sedation. Use with caution; may allow dose reduction of pharmaceuticals.
• MAOIs: Theoretical interaction due to harman alkaloid content, though clinical significance is unlikely at normal doses.
• Anticoagulants: Some passionflower species contain coumarin compounds — monitor.
• Antihypertensives: Additive blood pressure lowering.

Energetics

Western Herbal Energetics

• Temperature: Cool to neutral
• Moisture: Slightly moistening
• Tissue State: Excitation (the primary tissue state addressed — nervous excitation, anxiety, insomnia, restlessness)
• Taste: Mildly bitter, slightly sweet

TCM Classification (Modern Integration)

• Temperature: Cool
• Flavor: Slightly bitter, slightly sweet
• Meridian entry: Heart, Liver
• Actions: Calms Shen, soothes Liver Qi stagnation with Heat, clears Heart Fire
• TCM pattern correspondence: Heart Fire / Liver Qi stagnation with Shen disturbance — the anxious, restless, insomniac patient with irritability, palpitations, and difficulty “turning off” the mind.

Ayurvedic Classification (Modern Integration)

• Rasa: Tikta (bitter), Madhura (sweet)
• Virya: Shita (cooling)
• Vipaka: Madhura (sweet)
• Dosha effects: Pacifies Pitta and Vata. Particularly suited for Pitta-type anxiety (hot, irritable, intense) and Vata-type insomnia (mind racing, unable to settle).

Functional Medicine Integration

HPA Axis Protocol — Stage 1 (High Cortisol)

Passionflower is a first-line nervine for Stage 1 HPA dysfunction where anxiety, insomnia, and nervous hyperexcitability dominate. It directly addresses the “wired but tired” presentation through GABAergic calming without sedating the patient into daytime dysfunction. Use in the evening and bedtime protocol alongside phosphatidylserine and magnesium glycinate.

Sleep Protocol

Passionflower is often the preferred botanical for patients who need sleep support without morning grogginess. Unlike valerian (which can cause morning heaviness in some patients), passionflower tends to improve sleep quality while preserving morning alertness. Excellent as nightly tea — the ritual of preparing and drinking the tea itself becomes part of the sleep hygiene practice.

Anxiety Protocol (Benzodiazepine Alternatives)

For patients seeking to reduce or eliminate benzodiazepine use, passionflower provides an evidence-based botanical bridge. The Akhondzadeh 2001 study provides clinical justification for this transition (under medical supervision). Passionflower can be combined with other GABAergic herbs (skullcap, lemon balm) and amino acids (L-theanine, GABA) for a comprehensive non-pharmaceutical anxiolytic protocol.

Gut-Brain Axis

Anxiety drives gut dysfunction through vagal and cortisol-mediated pathways (reduced motility, increased permeability, altered microbiome). By calming the nervous system, passionflower indirectly supports gut healing — the “top-down” approach to gut-brain axis restoration.

Four Directions Connection

Primary Direction: Jaguar (West — Emotional Healing)

Passionflower is the Jaguar’s herb — the herb of facing darkness without being consumed by it. The Jaguar walks in the shadows, in the liminal space between waking and sleeping, between control and surrender. Anxiety is the fear of what lives in that darkness. Insomnia is the refusal to enter it. Passionflower does not force us into the dark — it gives us the courage to walk there willingly. Its GABAergic calming is not numbness — it is the quieting of the false alarm, so that we can hear what the darkness actually has to say. The Jaguar teaches that transformation happens not in the light but in the cave. Passionflower is the herb that helps us enter that cave.

Secondary Direction: Hummingbird (North — Soul Journey)

The name “passionflower” — given by Spanish missionaries who saw Christ’s Passion in the flower’s structure — connects this plant to the Hummingbird’s domain of meaning, sacred narrative, and the soul’s journey through suffering toward transcendence.

Tertiary: Serpent (South — Physical Body)

The physical relaxation — muscle tension release, reduced blood pressure, physical calming — serves the Serpent’s domain of embodied healing.

References

1. Akhondzadeh, S., Naghavi, H.R., Vazirian, M., et al. (2001). Passionflower in the treatment of generalized anxiety: a pilot double-blind randomized controlled trial with oxazepam. Journal of Clinical Pharmacy and Therapeutics, 26(5), 363-367.

2. Appel, K., Rose, T., Fiebich, B., et al. (2011). Modulation of the GABA system by Passiflora incarnata L. Phytotherapy Research, 25(6), 838-843.

3. Ngan, A., & Conduit, R. (2011). A double-blind, placebo-controlled investigation of passionflower herbal tea on subjective sleep quality. Phytotherapy Research, 25(8), 1153-1159.

4. Movafegh, A., Alizadeh, R., Hajimohamadi, F., et al. (2008). Preoperative oral Passiflora incarnata reduces anxiety before surgery. Anesthesia and Analgesia, 106(6), 1728-1732.

5. Dantas, L.P., et al. (2017). Effects of passiflora incarnata and midazolam for control of anxiety in patients undergoing dental extraction. Medicina Oral, Patologia Oral y Cirugia Bucal, 22(1), e95-e101.

6. Miroddi, M., Calapai, G., Navarra, M., Minciullo, P.L., & Gangemi, S. (2013). Passiflora incarnata L.: Ethnopharmacology, clinical application, safety and evaluation of clinical trials. Journal of Ethnopharmacology, 150(3), 791-804.

7. Janda, K., Wojtkowska, K., Jakubczyk, K., Antoniewicz, J., & Skonieczna-Zydecka, K. (2020). Passiflora incarnata in Neuropsychiatric Disorders — A Systematic Review. Nutrients, 12(12), 3894.

8. Sarris, J., McIntyre, E., & Camfield, D.A. (2013). Plant-based medicines for anxiety disorders, Part 2. CNS Drugs, 27(4), 301-319.