Passionflower (Passiflora incarnata)
Summary
Small trials suggest passionflower may ease anxiety before surgery or dental work and slightly improve self-rated sleep quality (grade D), and a Cochrane review found too few trials to draw conclusions. It can cause drowsiness, may interact with anaesthesia, and NCCIH advises against use in pregnancy.
Key facts
- 500 mg 90 minutes before surgery lowered anxiety scores without extra sedation (n = 60)[2]
- One week of passionflower tea improved self-rated sleep quality in a 41-person crossover[3]
- Cochrane: only 2 eligible trials (198 people), too few for conclusions[4]
- NCCIH advises telling your clinician if used within 2 weeks of surgery (possible anaesthesia interaction)[7]
- NCCIH: should not be used in pregnancy because it may induce uterine contractions[7]
- 5 graded human outcomes on this page
- October 13, 2026
How it works
ProposedPassionflower is traditionally classed as a sedative; how its constituents act in people is not established, and NCCIH notes it may slow the nervous system when combined with anaesthesia.[7]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Anxiety | Grade D | Mixed | Systematic review of 2 trials · n = 198 · 2007 | 4 rows |
| Sleep | Grade D | Improved | Crossover RCT · n = 41 · 2011 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Anxiety disorders (systematic review) | Mixed | Grade D | Systematic review · n = 198 · 2007 Adults with anxiety disorders in 2 RCTs Form: Passiflora extracts vs benzodiazepines · Dose: As used in each trial · Duration: 4 weeks One trial found no difference from a benzodiazepine; dropout rates were similar. The reviewers judged the trials too few to permit conclusions. | 17253512 (opens PubMed)Source [4] |
| Anxiety before ambulatory surgery | Improved | Grade D | RCT · n = 60 · 2008 Adults having outpatient surgery (Iran) Form: Passiflora incarnata tablets (Passipy) vs placebo · Dose: 500 mg single dose, 90 minutes before surgery · Duration: Single dose Anxiety scores were significantly lower than placebo (P < 0.001) with no difference in sedation, psychomotor recovery or discharge time. | 18499602 (opens PubMed)Source [2] |
| Anxiety during third-molar extraction | Improved | Grade D | RCT · n = 54 · 2024 Adults having wisdom-tooth extraction (three arms) Form: Passiflora incarnata vs valerian vs placebo · Dose: Single dose (amount not stated in abstract) · Duration: Single procedure State anxiety fell from before to after surgery with passionflower and with valerian, but not with placebo (P = 0.129). | 38743126 (opens PubMed)Source [6] |
| Subjective sleep quality | Improved | Grade D | Crossover RCT · n = 41 · 2011 Healthy adults aged 18–35 with mild sleep fluctuations Form: Passionflower herbal tea vs placebo tea · Dose: One cup daily · Duration: 1 week per arm Sleep quality rated better with passionflower (P < 0.01); the other five sleep-diary measures did not differ. | 21294203 (opens PubMed)Source [3] |
| Generalized anxiety disorder symptoms | Mixed | Grade D | RCT · n = 36 · 2001 Outpatients with DSM-IV generalized anxiety disorder (Iran) Form: Passiflora extract drops vs oxazepam · Dose: 45 drops/day (vs oxazepam 30 mg/day) · Duration: 4 weeks Both groups improved with no significant difference at 4 weeks; oxazepam acted faster but caused more job-performance problems. | 11679026 (opens PubMed)Source [1] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Passionflower tea | Varies[3] | Low-dose traditional preparation.[3] | NCCIH: may be safe as a tea for up to 7 nights.[7] | Sleep quality |
| Tablets, capsules or liquid extracts | Varies[1][2] | Doses vary by preparation.[1][2] | NCCIH: daily extract may be safe for up to 8 weeks; drowsiness, dizziness and confusion possible.[7] | Anxiety before procedures; GAD |
Studied doses
Doses studied in human trials ranged from one cup of passionflower tea daily for a week to 45 drops/day of liquid extract for 4 weeks, with a single 500 mg tablet used before surgery.[1][2][3]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Medicines
- Anaesthesia and perioperative sedativesNIH fact sheetNCCIH: passionflower with anaesthesia or other surgical medicines might slow the nervous system too much.[7]
- Other sedating medicines and alcoholNIH fact sheetNot studied directly. NCCIH lists drowsiness, dizziness and confusion as possible side effects, so effects could add to other sedating medicines or alcohol.[7]
Who should be careful
- Pregnancy
- NCCIH: passionflower should not be used during pregnancy as it may induce uterine contractions; breastfeeding safety is unknown.[7]
- Upcoming surgery
- Tell your clinician if you use it within 2 weeks of a scheduled operation.[7]
- Driving or hazardous work
- Drowsiness, dizziness and confusion are possible side effects.[7]
- Heart rhythm problems
- A case report described prolonged QTc and nonsustained ventricular tachycardia after passionflower at usual doses.[5]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Reported toxicity
- Case report
- A 34-year-old woman developed severe nausea, vomiting, drowsiness, prolonged QTc and nonsustained ventricular tachycardia after a passionflower remedy at therapeutic doses and needed cardiac monitoring.[5]
Frequently asked questions
Does passionflower help anxiety?
Small trials found lower anxiety before surgery and dental work, but a Cochrane review judged the evidence too thin for conclusions.[2][4][6]
Does passionflower help sleep?
One week of passionflower tea improved self-rated sleep quality in a small crossover; other sleep measures did not change.[3]
Is passionflower safe?
NCCIH says teas for up to a week and extracts for up to 8 weeks may be safe; drowsiness, dizziness and confusion can occur.[7]
Can I use passionflower in pregnancy?
No. NCCIH advises against it because it may cause uterine contractions.[7]
Sources
- [1]Passionflower in the treatment of generalized anxiety: a pilot double-blind randomized controlled trial with oxazepam.. J Clin Pharm Ther, 2001. pilot-RCT
- [2]Preoperative oral Passiflora incarnata reduces anxiety in ambulatory surgery patients: a double-blind, placebo-controlled study.. Anesth Analg, 2008. RCT
- [3]A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality.. Phytother Res, 2011. crossover-RCT
- [4]Passiflora for anxiety disorder.. Cochrane Database Syst Rev, 2007. systematic-review
- [5]Toxicity of Passiflora incarnata L.. J Toxicol Clin Toxicol, 2000. observational
- [6]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. RCT
- [7]Passionflower: Usefulness and Safety. NIH National Center for Complementary and Integrative Health, 2025. fact-sheet
What changed
- Editorial evidence re-review: the sedatives/alcohol interaction is now labelled as an inference from NCCIH's side-effect list rather than an NCCIH statement. Trial and Cochrane numbers re-checked.
- Second-pass self-review: every PMID re-checked against NCBI esummary (title, year, no retraction or expression-of-concern flag), every dose, n and duration re-read against the PubMed abstract or PMC full text, grades held conservative, and interactions limited to what a cited source supports.
- First draft. Source titles and years taken from NCBI E-utilities esummary; abstracts read for every evidence row.