Passionflower is one of the most popular herbal sleep aids, yet only 2 trials have tested it alone on sleep. Together they enrolled 151 people for 1 to 2 weeks.
Both found something, and both found less than the labels imply.
Quick Answer: Does Passionflower Help You Sleep?
Possibly, a little. In a 2011 trial, 41 healthy adults drank passionflower tea for a week and rated sleep quality better on 1 of 6 diary measures. In a 2020 trial of 110 adults with insomnia, 2 weeks of extract added about 23 minutes of sleep. Sleep efficiency and night waking did not beat placebo.
Key Takeaways
- Only 2 trials have tested passionflower alone on sleep, 151 people.
- A 2011 tea trial improved 1 of 6 sleep-diary measures.
- A 2020 insomnia trial added about 23 minutes of total sleep.
- Sleep efficiency and night waking did not beat placebo in 2 weeks.
- NCCIH says tea may be safe up to 7 nights, extract 8 weeks.
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What Has Actually Been Tested
Several sleep trials mention passionflower, but most test blends with valerian or hops. Only 2 test it on its own.
| Trial | People | Form | Length | Main finding |
|---|---|---|---|---|
| Tea crossover, 2011 | 41 healthy adults | 1 cup of tea nightly | 1 week per arm | Better sleep quality rating |
| Insomnia trial, 2020 | 110 with insomnia disorder | Extract | 2 weeks | About 23 minutes more sleep |
That is the whole single-herb sleep literature: 151 people, none followed longer than 2 weeks.
Where these 2 trials sit in the wider evidence is set out in our passionflower overview.
The Tea Trial
This is the study quoted on most product pages, including older versions of our own.
- Who: 41 adults aged 18 to 35, sleeping reasonably well.
- Design: Passionflower tea or placebo tea, 1 week each, crossed over.
- Measured: 6 sleep-diary measures, plus lab sleep studies in 10 people.
- Result: Sleep quality rated better; the other 5 measures did not differ.
The authors described a short-term subjective benefit from a low dose in healthy adults with mild fluctuations in sleep quality.[1]A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality — Phytotherapy Research (2011) View source That is a careful claim, and it is worth keeping it that size.
The Insomnia Trial
The 2020 study is the better test, because it enrolled people with diagnosed insomnia and measured sleep in a lab.
- Who: 110 adults meeting DSM-5 criteria for insomnia disorder.
- Design: Extract or placebo for 2 weeks, double-blind.
- Measured: Overnight polysomnography, diaries and 2 insomnia scales.
- Result: Total sleep time up about 23 minutes against placebo.
Sleep efficiency and time awake after falling asleep improved within the passionflower group, but not compared with placebo.[2]Effects of Passiflora incarnata Linnaeus on polysomnographic sleep parameters in subjects with insomnia disorder — International Clinical Psychopharmacology (2020) View source How the extract doses compare with a capsule is in how the trial doses translate.
What 23 Minutes Means
A headline number needs its context, and this one has 4 pieces.
- The comparison: Plus 23 minutes against almost 0 change on placebo.
- The margin: P = 0.049, just inside the usual cutoff of 0.05.
- The spread: A standard deviation of about 54 minutes, larger than the effect.
- The rest: Efficiency and night waking were no better than placebo.
NCCIH reads the same evidence as a possible gain in total sleep time, with mixed effects on falling asleep and staying asleep.[3]Passionflower: Usefulness and Safety — National Center for Complementary and Integrative Health View source
Why It Might Help Some Nights
The proposed mechanism is the same one behind most sleep medication, which is also the reason for caution.
- Target: GABA receptors, which dampen brain activity.
- Shared with: Valerian, lemon balm and several sleeping pills.
- Evidence level: Suggestive, and not fully understood.
A 2021 review found that herbal extracts may work partly through GABA receptors, while calling the mechanism in insomnia incompletely understood.[4]Herbal Remedies and Their Possible Effect on the GABAergic System and Sleep — Nutrients (2021) View source The other herbs sold for sleep are weighed in passionflower against valerian and chamomile.
What It Does Not Replace
Chronic insomnia has a first-line treatment with far more evidence behind it than any herb.
- First line: Cognitive behavioral therapy for insomnia, CBT-I.
- Rule out: Sleep apnea, especially with snoring or daytime sleepiness.
- Do not combine: With prescription sleeping pills or alcohol.
- See someone: If poor sleep has lasted 3 months or more.
Stacking matters here. In 1 case report, a man on lorazepam who added valerian and passionflower developed tremor, dizziness and muscle fatigue.[5]Interactions of Valeriana officinalis L. and Passiflora incarnata L. in a patient treated with lorazepam — Phytotherapy Research (2009) View source
Trying It Sensibly
If you want to try it, these terms stay close to what was tested.
- Length: 1 to 2 weeks, then judge honestly.
- Timing: In the evening, not before you drive.
- Alone: No alcohol, no other sedatives, no second sleep herb.
- Measure: Keep a simple diary, as the trials did.
For a fixed amount with no alcohol in it, a once-daily passionflower capsule is the simplest way to run that 2-week test.
Speak to a Clinician Before Taking Passionflower If
- You take a benzodiazepine, a sleeping pill, an opioid or another sedating prescription
- You drink alcohol in the evening, or need to drive after taking it
- You already take valerian, kava, hops or another sedating herb
- You are pregnant, trying to conceive or breastfeeding
- You have surgery or a dental procedure with sedation within 2 weeks
Frequently Asked Questions
Does passionflower actually help you sleep? +
Modestly, on 2 small trials. 1 improved a sleep-quality rating; the other added about 23 minutes of total sleep in insomnia.
Can you take passionflower every night? +
NCCIH says tea may be safe for up to 7 nights and daily extract for up to 8 weeks. Longer nightly use has not been studied.
Is passion flower better than melatonin? +
No trial has compared them. They also do different jobs: melatonin shifts timing, while passionflower was tested on 2 measures of sleep quantity and quality.
What is the strongest herb for insomnia? +
None has been proven strongest. Passionflower's best sleep result is 23 extra minutes in 1 trial of 110 people.
Does passionflower make you sleepy? +
It can. NCCIH lists drowsiness as 1 possible side effect, which is why driving after a dose is a bad idea.
How long before bed should I take passionflower? +
No sleep trial tested timing. The tea trial used 1 cup in the evening; many people take it 30 to 60 minutes before bed.
Can I take passionflower with a sleeping pill? +
Not without your prescriber's advice. Both may act on GABA receptors, and 1 case report linked the combination with lorazepam to dizziness.
Does passionflower help you stay asleep? +
Not clearly. In the 2020 trial, time awake after falling asleep did not differ from placebo after 2 weeks.
Is passionflower tea as good as capsules for sleep? +
The tea trial and the extract trial are not comparable. 0 trials have tested our capsule or tincture directly.
Related Reading
- Passionflower and Anxiety, Trial by Trial
- Passionflower Side Effects and Interactions
- The Capsule and the Tincture Compared
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