Passionflower

What it is

Passionflower (Passiflora incarnata) is a climbing vine native to the southeastern United States; its leaves, stems and flowers are used in teas, tinctures and extracts. It's a different species from the plant that produces most store-bought passion fruit.

How it works

Passionflower contains flavonoids such as chrysin and vitexin, along with other compounds that in lab and animal studies appear to act on the brain's GABA system — the same calming pathway targeted by many anti-anxiety and sleep medications. How much of this happens at the doses people actually take isn't well established.

What it's been studied for

Commonly taken for nervousness, mild anxiety and trouble falling asleep, often in blends with other calming herbs.

What the evidence shows

Limited: a handful of small trials suggest passionflower may ease anxiety (including before surgery or dental procedures) and modestly improve self-rated sleep quality. A Cochrane review found only two small anxiety trials and concluded there wasn't enough evidence to draw firm conclusions. The key limitations are small sample sizes, short durations and widely varying products.

Who should consider it

Adults with mild, situational nervousness or occasional trouble falling asleep might reasonably try it, especially if they prefer a gentle herbal option. It's not a good choice for people already taking sedating medications, for those who are pregnant, or for anyone who needs to stay alert. Persistent anxiety or insomnia deserves an evaluation, since proven treatments — including cognitive behavioral therapy — exist.

Amounts commonly studied

There's no well-established dose; studies used standardized extracts in anxiety trials and, in one sleep study, a cup of passionflower tea at bedtime for a week.

How to take it

Products and doses vary widely, so follow the label on a reputable product and start low. For sleep, it's usually taken in the evening; the sleep study used a cup of tea about an hour before bed for a week. Talk to your provider before combining it with any prescription sleep, anxiety or pain medication, and stop it about two weeks before a planned surgery.

Forms & absorption

Available as dried herb for tea, liquid extracts, tinctures and capsules, and frequently in combination sleep or calm products. Strength varies considerably between products, and most don't list a standardized marker compound.

Food sources

None — the medicinal parts are the leaves, stems and flowers of Passiflora incarnata, taken as tea or extract; the passion fruit sold in stores is usually a different species (Passiflora edulis) and isn't a substitute.

Safety & interactions

Drowsiness, dizziness and mild confusion are the most commonly reported side effects, so avoid driving until you know how it affects you. It can add to the effects of sedatives, benzodiazepines, sleep aids, antihistamines and alcohol, and it's commonly advised to stop it about two weeks before surgery. Avoid it during pregnancy (it has traditionally been considered a uterine stimulant) and while breastfeeding, since safety hasn't been established.

Common questions

Does passionflower help with sleep?

One small trial found a nightly cup of passionflower tea modestly improved self-rated sleep quality over a week. That's encouraging but far from definitive.

Can I take it with melatonin or other sleep aids?

Combining calming products can add up to more drowsiness than you expect, especially with prescription sleep or anxiety medications. Check with your provider or pharmacist before stacking them.

Is it habit-forming?

There's no good evidence that passionflower is habit-forming the way some sleep medications can be. Its main risks are drowsiness and interactions with other sedating substances.