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Passionflower for Sleep and Anxiety: What the Evidence Shows

Passionflower is a traditional calming herb. Small studies suggest it may ease mild anxiety and improve sleep a little. Here is what the research shows and who should avoid it.

Edited by Anmar ArabPublished 17 October 2026, 7 min read
On this page
  1. Quick answer
  2. What the research says
  3. How people use it
  4. Possible side effects and interactions
  5. Who should avoid it
  6. When to see a doctor
  7. Frequently asked questions

Quick answer

Passionflower (Passiflora incarnata) is a climbing plant that has long been used as a calming herb. The research on it is encouraging but thin.

  • For anxiety: a small number of studies suggest it may reduce anxiety, including nervousness before surgery or a dental procedure. The US National Center for Complementary and Integrative Health (NCCIH) says these conclusions are not definite.
  • For sleep: limited research suggests it may increase total sleep time in adults with insomnia, but results for falling asleep faster and staying asleep are mixed.
  • Safety: short-term use may be safe for most adults. It can cause drowsiness, dizziness and confusion, and it should not be used in pregnancy.
  • Bottom line: it may be worth trying for mild, short-term stress or poor sleep, but it is not a treatment for an anxiety disorder or long-term insomnia.

What the research says

Passionflower is native to the south-eastern United States and Central and South America, where it is also known as maypop. Today it is sold as a tea and as dietary supplements, often mixed with other calming herbs such as valerian, hops or lavender.

NCCIH's overall view. NCCIH's fact sheet, updated in 2025, says passionflower has not been studied extensively. A small amount of research suggests that taking it by mouth may reduce anxiety. For sleep, a small amount of research suggests it may increase total sleep time in adults with insomnia, while its effects on how quickly people fall asleep and how well they stay asleep are mixed. There is not enough evidence to say whether it helps stress, ADHD, menopausal symptoms or other conditions it is marketed for.

A 2020 systematic review. A review in the journal Nutrients looked at nine randomised clinical trials of passionflower in anxiety and related problems. Most of the trials reported lower anxiety levels after taking passionflower, although the effect seemed less clear in people with only mild symptoms. The trials were short, lasting from a single day to about a month, and used different products and anxiety scales, which makes them hard to compare. No serious side effects were reported.

A dental surgery trial. Passionflower has been studied in dental settings because many people feel anxious before treatment. In a trial by Dantas and colleagues, 40 adults having both lower wisdom teeth removed received either 260 mg of passionflower or 15 mg of midazolam, a prescription sedative, by mouth 30 minutes before each operation. The design was double-blind and crossover, so each person tried both. Anxiety scores, heart rate and blood pressure were similar with both treatments, and more than 70% of people felt calm or only a little anxious with either. About 20% of people had complete memory loss of the procedure after midazolam, while passionflower had little effect on memory. This was a single small study in a supervised dental clinic, so it does not mean passionflower can replace sedation that a dentist has planned.

A sleep trial using tea. In a study by Ngan and Conduit, published in Phytotherapy Research in 2011, 41 adults aged 18 to 35 drank passionflower tea or a placebo tea for a week and kept a sleep diary, then switched after a one-week break. Of six sleep diary measures, only sleep quality was rated significantly better with passionflower. The authors described the benefit as short term and based on how people felt, rather than on objective sleep measurements.

European regulators. The European Medicines Agency (EMA) has assessed passionflower as a traditional herbal medicine for relief of mild symptoms of mental stress and to aid sleep. This status is based on long-standing use rather than firm clinical trial evidence, and these medicines are only for adults and adolescents over 12.

Taken together, the evidence is best described as limited: a few small, short trials with some positive findings, but not enough to be confident.

How people use it

There is no single agreed dose, and products differ a lot in strength. The amounts below describe what was used in studies, not a recommendation.

  • Tea: the sleep study used a cup of passionflower tea over a one-week period. NCCIH says tea may be safe for up to 7 nights.
  • Extracts and tablets: the dental study used a single 260 mg dose 30 minutes before the procedure. NCCIH says daily extract may be safe for up to 8 weeks.
  • Follow the label. EMA advises checking the package leaflet, or asking a doctor or pharmacist, for how much to take and for how long.
  • Choose single-herb products if you want to know what you are taking. Many products combine several herbs. NIH's LiverTox database cites reviews that question the purity of over-the-counter passionflower products.
  • Pair it with good sleep habits. The NHS recommends keeping regular sleep and wake times, winding down for an hour before bed, keeping the bedroom dark and quiet, and avoiding caffeine, alcohol and large meals late in the evening.
Passionflower can make you drowsy. Do not drive or use machinery until you know how it affects you, and talk to a doctor if poor sleep or anxiety lasts for weeks or is affecting your daily life.

Possible side effects and interactions

  • Common side effects: NCCIH lists drowsiness, dizziness and confusion. LiverTox adds that unsteadiness can occur but says side effects by mouth are uncommon.
  • Liver safety: LiverTox says passionflower has not been linked to liver injury, though it has not been tested in trials with careful liver monitoring.
  • Surgery and anaesthesia: NCCIH warns that passionflower may interact with some anaesthesia drugs and other medicines used around surgery, possibly slowing the nervous system too much. Tell your surgical team, and check with a doctor if surgery is planned within 2 weeks.
  • Other medicines: NCCIH advises checking with a healthcare provider before using passionflower with any medicine. Because it can cause drowsiness, take particular care if you also take sleeping tablets, other sedating medicines or drink alcohol.
  • Skin use: NCCIH says the safety of using passionflower on the skin is unknown.

Who should avoid it

  • Pregnant women. NCCIH says passionflower should not be used during pregnancy because it may cause contractions of the womb.
  • Breastfeeding mothers. Little is known about its safety while breastfeeding, so it is best avoided unless a doctor advises otherwise.
  • Children under 12. EMA says traditional passionflower medicines are only for adults and adolescents over 12.
  • People having surgery soon, for the reason above.
  • People taking prescribed medicines for anxiety, depression or sleep. Do not add passionflower or swap it for your medicine without speaking to your doctor first.

When to see a doctor

Herbal sleep aids are meant for short-term problems. The NHS says pharmacy sleep remedies may help for 1 to 2 weeks but should not be used for longer. See a doctor if:

  • You have had trouble sleeping for months, or for 3 months or more, which the NHS classes as long-term insomnia.
  • Changing your sleep habits has not helped.
  • Poor sleep is making it hard to cope with work, family or daily life.
  • Worry or anxiety is constant, is getting worse, or is stopping you from doing normal things.
  • You feel confused, very dizzy or unusually drowsy after taking passionflower.

If you are in crisis or having thoughts of harming yourself, seek urgent help straight away through emergency services or a local crisis line.

Frequently asked questions

Is passionflower tea safe to drink every night?

NCCIH says passionflower tea may be safe for up to 7 nights, and daily extracts for up to 8 weeks. Longer use has not been well studied, so it makes sense to treat it as a short-term option.

Does passionflower work as well as prescription anxiety medicine?

One small dental trial found similar anxiety scores with passionflower and midazolam before wisdom tooth removal. That single result in a supervised clinic is not enough to say passionflower works as well as prescribed medicines, and it should never replace treatment your doctor has prescribed.

Can I take passionflower with valerian or chamomile?

Passionflower is often sold in blends with valerian, hops or lavender. Combining calming herbs may add to drowsiness, and blends are harder to judge for strength and purity. Check with a pharmacist, especially if you take other medicines.

How quickly does passionflower work?

In the dental study, a single dose was taken 30 minutes before treatment. In the sleep study, people drank the tea over a week. Effects reported in research were modest.

References

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