NutriDex

The Supplement Research Compendium
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Passionflower

Passiflora incarnata

A calming herb with real but modest evidence for anxiety.

Moderate evidence 🌙Sleep & Mood

✚ Updated · How we grade evidence

Evidence tier
Moderate
Research weight
Citations
8 verified / 8
Classification
Sleep & Mood
❝
What the evidence says. Graded moderate: several small double-blind RCTs show genuine short-term anxiety reduction — even matching oxazepam for generalized anxiety and easing pre-surgical nerves — but trials are tiny (n≈30–60), brief, use varied preparations, and sleep evidence rests on one small tea study. (Moderate evidence: Several controlled trials; effects real but modest or context-dependent.)

What is Passionflower?

Passionflower (Passiflora incarnata) is a sleep and mood supplement used for ease anxiety. NutriDex grades the human evidence as Moderate. Passionflower (Passiflora incarnata) is a traditional calming herb thought to act mainly through GABA-A modulation, with flavonoids like vitexin as likely actives. The best human data are for anxiety: a 4-week RCT in generalized anxiety disorder found a flavonoid extract about as effective as oxazepam (30 mg) but with less daytime job impairment, and several placebo-controlled trials show a single ~500 mg dose meaningfully lowers pre-operative and dental anxiety without sedation. For sleep, evidence is thinner — a small crossover trial of passionflower tea improved subjective sleep quality by only a few percent over placebo in healthy adults. Overall the anxiolytic signal is real but the trials are small (often n=30–60), short (days to 4 weeks), heterogeneous in preparation and dose, and several are non-Western single-center studies. It is best viewed as a mild, short-term calming aid, not a proven treatment for chronic anxiety or insomnia.

Purported Benefits

✓Ease anxiety
✓Calm before procedures
✓Support sleep quality
✓Reduce restlessness

Evidence by outcome

The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.

OutcomeEvidenceEffectStudies
Reduce pre-procedural anxietySeveral placebo-controlled RCTs show a single ~500 mg dose lowers surgical/dental anxiety without sedation. Moderate ↑ benefit · moderate 4
Ease generalized anxietyOne 4-wk GAD RCT matched oxazepam, but n=36 and preparations are heterogeneous. Preliminary ↑ benefit · moderate 1
Improve sleep qualityOne crossover trial of tea improved subjective sleep only ~5% over placebo; other measures unchanged. Preliminary ↑ benefit · negligible 1

Dosing & Compounds

Typical Dose
Extracts ~250–800 mg/day, or a tea/tincture standardized to flavonoids; single ~500 mg doses are used 30–90 min before stressful events.
Active Compounds
Flavonoids (vitexin, isovitexin)ChrysinHarmala alkaloids (trace)

Safety & Cautions

Generally well tolerated short-term; the main effects are drowsiness, dizziness and occasional confusion, so it can add to the sedation of benzodiazepines, sleep aids, alcohol and other CNS depressants. Because it may have mild blood-thinning and additive sedative effects, use caution with anticoagulants and before surgery (stop ~2 weeks prior), and theoretically it could lower blood pressure or blood sugar alongside those medications. Avoid in pregnancy (it can stimulate the uterus) and while breastfeeding, and don't drive after dosing until you know how it affects you. Educational only — always check with your doctor or pharmacist before combining Passionflower with any medicine.

Passionflower drug interactions

Known or theoretical interactions between Passionflower and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining Passionflower with any medicine.

Caution
Benzodiazepines, sleep medicines & alcohol
Additive drowsiness and sedation; can slow the nervous system too much, impairing alertness and coordination.
Passionflower has CNS-depressant (GABAergic) activity that adds to sedatives, sleep medicines and alcohol. NCCIH — Passionflower

Key Studies

Systematic review Janda 2020 ✓ PubMed
Systematic review of 9 trials: most show reduced anxiety with Passiflora and no cognitive harm, but calls for larger studies; sleep data limited.
RCT Rokhtabnak 2016 ✓ PubMed
As premedication (n=52), Passiflora reduced anxiety as well as melatonin, but melatonin preserved cognition (digit-symbol test) better.
RCT Dantas 2017 ✓ PubMed
Before dental surgery, Passiflora 260 mg gave anxiolysis similar to midazolam 15 mg, though many patients preferred midazolam's amnesia.
RCT Aslanargun 2012 ✓ PubMed
Oral Passiflora before spinal anesthesia (n=60) blunted the pre-procedure rise in STAI anxiety vs placebo, without affecting psychomotor recovery.
RCT Ngan & Conduit 2011 ✓ PubMed
Crossover trial (n=41 healthy adults): passionflower tea improved self-rated sleep quality ~5% over placebo over 7 days; other sleep measures unchanged.
RCT Kaviani 2013 ✓ PubMed
Before periodontal treatment (n=63), Passiflora drops cut dental anxiety from 12.1 to 8.5 vs little change in placebo/control (p<0.0001).
RCT Akhondzadeh 2001 ✓ PubMed
In GAD (n=36, 4 wk), Passiflora extract (45 drops/day) matched oxazepam 30 mg for anxiety with significantly less job-performance impairment.
RCT Movafegh 2008 ✓ PubMed
Oral Passiflora 500 mg 90 min pre-surgery (n=60) significantly lowered anxiety vs placebo (P<0.001) without sedation or psychomotor impairment.
8 sources cited · 8 verified Search all studies on PubMed ↗

Common questions about Passionflower

What is Passionflower used for?

Passionflower is most often taken for Ease anxiety, Calm before procedures, Support sleep quality, Reduce restlessness. A calming herb with real but modest evidence for anxiety.

Does Passionflower work — what does the evidence say?

Moderate evidence. Several controlled trials; effects real but modest or context-dependent. Passionflower (Passiflora incarnata) is a traditional calming herb thought to act mainly through GABA-A modulation, with flavonoids like vitexin as likely actives. The best human data are for anxiety: a 4-week RCT in generalized anxiety disorder found a flavonoid extract about as effective as oxazepam (30 mg) but with less daytime job impairment, and several placebo-controlled trials show a single ~500 mg dose meaningfully lowers pre-operative and dental anxiety without sedation. For sleep, evidence is thinner — a small crossover trial of passionflower tea improved subjective sleep quality by only a few percent over placebo in healthy adults. Overall the anxiolytic signal is real but the trials are small (often n=30–60), short (days to 4 weeks), heterogeneous in preparation and dose, and several are non-Western single-center studies. It is best viewed as a mild, short-term calming aid, not a proven treatment for chronic anxiety or insomnia.

What is the typical dose of Passionflower?

Extracts ~250–800 mg/day, or a tea/tincture standardized to flavonoids; single ~500 mg doses are used 30–90 min before stressful events.

Is Passionflower safe? Any cautions or side effects?

Generally well tolerated short-term; the main effects are drowsiness, dizziness and occasional confusion, so it can add to the sedation of benzodiazepines, sleep aids, alcohol and other CNS depressants. Because it may have mild blood-thinning and additive sedative effects, use caution with anticoagulants and before surgery (stop ~2 weeks prior), and theoretically it could lower blood pressure or blood sugar alongside those medications. Avoid in pregnancy (it can stimulate the uterus) and while breastfeeding, and don't drive after dosing until you know how it affects you.

How many studies support Passionflower?

NutriDex cites 8 sources for Passionflower, graded "Moderate".

Does Passionflower interact with any medications?

Yes — known or theoretical interactions include: Sedatives (benzodiazepines, opioids, alcohol) (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining Passionflower with any medicine.

Cite this page
APA

Peh, D. (2026). Passionflower (Passiflora incarnata): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 26 Jun 2026, from https://nutridex.info/s/passionflower

BibTeX
@misc{nutridex_passionflower,
  author       = {Peh, Daryl},
  title        = {Passionflower (Passiflora incarnata): Benefits, Dosage, Side Effects \& Evidence},
  year         = {2026},
  howpublished = {NutriDex --- The Supplement Research Compendium},
  url          = {https://nutridex.info/s/passionflower},
  note         = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-06-26}
}

For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.

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