Home Ingredients Passionflower (Passiflora incarnata)
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Passionflower (Passiflora incarnata)

Passiflora incarnata
Evidence Level
Moderate
2 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Passionflower is a flowering vine native to the Americas — used in traditional medicine since pre-Columbian times for anxiety, insomnia, and 'nervous tension.' Distinguished by activity at GABA-A receptor (similar mechanism to benzodiazepines but much milder). Modest evidence for generalized anxiety, sleep onset, and as pre-surgical anxiolytic. Component of many sleep/calming herbal blends. Approved for anxiety and sleep disorders in some European countries.

Studied Dose 300-500 mg/day standardized extract; tea 1-2 g dried herb per cup; tincture 1-4 mL three times daily
Active Compound Chrysin (flavonoid), vitexin, harman alkaloids, GABA, apigenin

Benefits

Generalized Anxiety Disorder (GAD)

RCT compared passionflower 45 drops/day vs oxazepam 30 mg/day for GAD over 4 weeks — equivalent anxiolytic efficacy with fewer side effects (less impairment of work performance) than oxazepam. Strongest single piece of evidence for passionflower anxiolysis.

Supported by Trial 1

Pre-Surgical / Pre-Procedural Anxiety

trial showed passionflower (Passipay) 500 mg given 90 minutes pre-surgery significantly reduced pre-operative anxiety vs placebo without delaying recovery. Useful for medical/dental procedure anxiety.

Supported by Trial 2

Sleep Quality and Onset

trial showed passionflower tea modestly improved sleep quality scores in healthy adults with mild sleep concerns. Effect modest. Often combined with valerian, lemon balm, hops in sleep formulations.

Supported by Trial 1, Trial 2

Opioid Withdrawal Adjunct

Akhondzadeh 2001 (separate trial) showed passionflower + clonidine more effective than clonidine alone for opioid withdrawal symptoms. Suggests benefit for withdrawal-associated anxiety.

Supported by Trial 2, Trial 1

ADHD Symptoms (Limited Evidence)

trial showed passionflower comparable to methylphenidate for some ADHD symptoms with fewer side effects in children — small study; not standard ADHD treatment.

Supported by Trial 1, Trial 2

Mechanism of action

1

GABA-A Receptor Modulation

Passionflower flavonoids (chrysin, apigenin, vitexin) bind benzodiazepine site of GABA-A receptor — mild positive allosteric modulators. Mechanism similar to benzodiazepines but much weaker affinity. Basis for anxiolytic and sleep effects.

2

Direct GABA Content

Passiflora plants contain GABA itself (the inhibitory neurotransmitter) — though oral GABA's CNS penetration is limited, passionflower's GABA content may contribute to local effects.

3

Harman Alkaloid MAO Inhibition (Modest)

Passionflower contains small amounts of beta-carbolines (harman, harmine, harmaline) with mild MAO inhibition — may modestly affect monoamine neurotransmitters. Generally not clinically significant at typical doses.

4

Chrysin Anxiolytic Activity

Chrysin (5,7-dihydroxyflavone) is a key passionflower flavonoid with anxiolytic effects — tested as a stand-alone anxiolytic. Aromatase inhibition is theoretical at high doses.

Clinical trials

1
Passionflower vs Oxazepam for GAD

Double-blind clinical trial comparing passionflower extract (45 drops/day) vs oxazepam (30 mg/day) in 36 GAD patients for 4 weeks.

36 GAD patients.

Equivalent anxiolytic efficacy. Oxazepam group had more impairment of job performance. Established passionflower as reasonable alternative to mild benzodiazepines for GAD.

2
Passionflower for Pre-Surgical Anxiety

Clinical trial of passionflower (Passipay 500 mg) 90 minutes pre-surgery vs placebo in 60 patients undergoing surgery.

60 surgical patients.

Significantly reduced pre-operative anxiety; no delay in psychomotor recovery. Established passionflower as practical pre-procedural anxiolytic.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated.
Drowsiness / sedation.
Dizziness.
Confusion or mental clouding (rare; usually high doses).
Allergic reactions rare.
GI distress.
Tachycardia paradoxical (rare).

Important Drug interactions

Benzodiazepines, sedatives, sleep aids — additive CNS depression.
Alcohol — additive sedation.
Anticoagulants — passionflower may modestly affect coagulation; theoretical.
MAO inhibitors — theoretical interaction (mild MAO activity); consult.
Hexobarbital and other barbiturates — additive CNS depression.
Hormone-sensitive conditions — chrysin's modest aromatase inhibition theoretical concern; minor at typical doses.
Pregnancy — uterotonic effects in some traditions; avoid supplementation.

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Frequently asked questions about Passionflower (Passiflora incarnata)

How much passionflower should I take?

Studies have used a range, often around 250 to 800 mg of extract per day, or passionflower tea in the evening. It is also a common ingredient in calming and sleep blends.

What is passionflower used for?

Passionflower is a calming herb studied for occasional anxiousness, relaxation, and sleep support. It is thought to work partly by supporting GABA activity, the body's calming signal.

When should I take passionflower?

For sleep, take it in the evening before bed; for daytime calm, smaller amounts are used. Because it can cause drowsiness, avoid driving or operating machinery after taking it, and do not combine it with alcohol.

Is passionflower safe?

It is generally well tolerated for short-term use; possible effects include drowsiness and dizziness. It can add to the effect of sedatives, and pregnant women should avoid it. Check with your doctor if you take sleep or anti-anxiety medication.

What is Passionflower?

Passionflower is a flowering vine native to the Americas — used in traditional medicine since pre-Columbian times for anxiety, insomnia, and 'nervous tension.' Distinguished by activity at GABA-A receptor (similar mechanism to benzodiazepines but much milder).

What is the recommended dosage of Passionflower?

The clinically studied dose is 300-500 mg/day standardized extract; tea 1-2 g dried herb per cup; tincture 1-4 mL three times daily Always follow the product label and check with a healthcare provider for personal advice.

Is Passionflower safe, and does it have side effects?

For most healthy adults, Passionflower is well tolerated at studied doses. Reported effects can include: Generally well-tolerated. Drowsiness / sedation. It may also interact with some medications. Passionflower is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Passionflower interact with any medications?

Possible interactions include: Benzodiazepines, sedatives, sleep aids — additive CNS depression. Alcohol — additive sedation. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Passionflower?

NutraSmarts rates the evidence for Passionflower as Moderate (3 out of 5). It is backed by 2 clinical trials and 6 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(6 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Janda K, Wojtkowska K, Jakubczyk K, Antoniewicz J, Skonieczna-Żydecka K. Passiflora incarnata in Neuropsychiatric Disorders-A Systematic Review. Nutrients. 2020;12(12):. doi: 10.3390/nu12123894.PubMedUsed to support: Systematic review of Passiflora incarnata across neuropsychiatric disorders, concluding it shows anxiolytic and sleep-supportive effects with good tolerability. Anchors the anxiety and sleep uses.
  2. Akhondzadeh S, Naghavi HR, Vazirian M, Shayeganpour A, Rashidi H, Khani M. Passionflower in the treatment of generalized anxiety: a pilot double-blind randomized controlled trial with oxazepam. J Clin Pharm Ther. 2001;26(5):363-7. doi: 10.1046/j.1365-2710.2001.00367.x.PubMedUsed to support: Double-blind RCT in generalized anxiety disorder: passionflower was comparable to oxazepam for anxiety with less daytime impairment. A foundational human trial behind the anxiety use.
  3. Ngan A, Conduit R. A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality. Phytother Res. 2011;25(8):1153-9. doi: 10.1002/ptr.3400.PubMedUsed to support: Double-blind, placebo-controlled trial in which a passionflower tea improved subjective sleep quality in healthy adults. Supports the sleep-support benefit.
  4. Miyasaka LS, Atallah AN, Soares BG. Passiflora for anxiety disorder. Cochrane Database Syst Rev. 2007;(1):CD004518. doi: 10.1002/14651858.CD004518.pub2.PubMedUsed to support: Cochrane systematic review of Passiflora for anxiety, noting promising but limited trial evidence and the need for larger studies. Supports the anxiety use while framing the evidence honestly.
  5. Lee J, Jung HY, Lee SI, Choi JH, Kim SG. Effects of Passiflora incarnata Linnaeus on polysomnographic sleep parameters in subjects with insomnia disorder: a double-blind randomized placebo-controlled study. Int Clin Psychopharmacol. 2020;35(1):29-35. doi: 10.1097/YIC.0000000000000291.PubMedUsed to support: Randomized trial using objective polysomnography found Passiflora improved measured sleep parameters in adults with insomnia. Strengthens the sleep evidence beyond questionnaires.
  6. Velasquez ACA, Tsuji M, Dos Santos Cordeiro L, Petinati MFP, Rebellato NLB, Sebastiani AM, da Costa DJ, Scariot R. Effects of Passiflora incarnata and Valeriana officinalis in the control of anxiety due to tooth extraction: a randomized controlled clinical trial. Oral Maxillofac Surg. 2024;28(3):1313-1320. doi: 10.1007/s10006-024-01259-6.PubMedUsed to support: Recent RCT in which Passiflora (with valerian) reduced situational anxiety before a dental procedure. Adds a modern controlled trial supporting the calming use.