What is Passion Flower?

Passion flower is a climbing vine from the southeastern United States. The dried leaves, stems and flowers are used as a calming herb. The plant is also called maypop.

People take it for mild anxiety, restlessness and trouble sleeping. It is sold as tea, tincture, capsules and tablets. It often appears in blended "sleep" or "calm" formulas.

The human evidence is thin. A few small trials hint at a mild calming effect, but they are short and not consistent. Long traditional use is not proof that it works, and it is not proof that it is safe.

How does Passion Flower work?

No one has pinned down how passion flower works.

The main idea involves GABA, a brain chemical that quiets nerve signals. In animal and cell studies, extracts appear to raise GABA activity. Some of the plant's flavonoids bind the same receptor sites as calming drugs in lab tests.

Whether this happens in people, at the amounts they actually take, is not established. Lab and animal work shows what a plant can do in a dish, not what it does in you.

There is a second problem. Products differ a lot in strength and plant part, so two bottles may not act the same way.

What forms does Passion Flower come in?

Passion flower is sold mainly as dried herb and as extracts. Most products use the leaves, stems and flowers rather than the fruit.

Common forms include:

Dried herb for tea, loose or in tea bags.

Liquid tincture, made with alcohol or glycerine.

Capsules and tablets of dried herb or dried extract.

Blended formulas with valerian, hops, lemon balm or magnesium.

The fruit, called maypop, is eaten as food in the southern United States. Eating the fruit is not the same as taking a concentrated extract.

Names on labels can mislead. Passiflora incarnata is the species used as a calming herb. Other Passiflora species sold as garden plants have not been studied the same way.

Where it comes from:

Passion flower has a long record in American folk and Eclectic medicine. Eclectic doctors of the late 1800s wrote about it for restlessness, broken sleep and "nervous" complaints.

It was listed in the United States National Formulary for part of the 20th century. It was later dropped, as proof of effect was lacking.

In Europe, regulators allow it as a traditional herbal remedy for mild stress and sleep problems. That status rests on long use and a basic safety record, not on strong trial results.

What does Passion Flower help with?

• Mild anxiety and nervousness: This is the best-studied use, and the evidence is still weak. Eclectic doctors used it for people they described as restless or on edge. One small four-week trial found it worked about as well as oxazepam, an anxiety drug. That trial had 36 people and no placebo-only arm. A Cochrane review later judged the overall evidence too thin to call. It may help mild everyday nerves in some people, and it may do nothing.
• Trouble falling asleep and poor sleep quality: Tradition treated it as a gentle sleep herb, not a knockout drug. One small study of passion flower tea found slightly better sleep ratings after a week. Other sleep measures did not change. If it helps you, expect a mild effect. It is not a treatment for long-term insomnia, and ongoing sleep problems need a doctor's look.
• Restlessness and fidgetiness: This use comes from tradition rather than from trials. American folk and Eclectic writers used it for people who could not settle. No good human trials test restlessness on its own. Treat this as an untested use.
• Anxiety before surgery or dental work: A small trial supports short-term use here, under medical care. In one study of 60 adults, a single dose before surgery lowered anxiety scores more than a dummy treatment. Sedation and recovery times were not worse. Do not copy this at home. Anything you take before an operation must be cleared with your surgeon and anaesthetist first.
• Opioid withdrawal symptoms, as an add-on only: One trial tested it alongside standard medical treatment, never instead of it. In 65 men coming off opioids, passion flower plus clonidine eased mental symptoms more than clonidine alone. Physical symptoms were about the same. This is a single small study. Opioid withdrawal needs medical supervision, and this herb is not a substitute for it.

Which foods are rich in Passion Flower?

Passion flower is not a nutrient, so no food supplies it in a meaningful way. The maypop fruit is eaten in the southern United States, but the calming herb is made from leaves, stems and flowers.

What are the side effects of Passion Flower?

• Drowsiness and slowed reactions
• Dizziness
• Confusion or muddled thinking, mostly at higher amounts
• Nausea or stomach upset
• Headache
• Allergic rash, itching or swelling
• Fast or uneven heartbeat, reported rarely
• Loss of coordination, reported rarely

Good to know:

Most people who take normal amounts for a short time have no trouble. The usual complaint is feeling sleepy or slow.

Serious problems are rare and mostly come from single case reports. These include a racing heart, deep drowsiness and allergic reactions.

Stop taking it and get medical advice if you feel very drowsy, faint, or your heart races.

How much Passion Flower should you take?

• Recommended daily: Labels on passion flower products usually suggest about 1 to 2 grams of dried herb per cup of tea, up to three cups a day. Tincture and capsule labels vary widely, because extract strengths differ. This is a note on what the market carries. It is not advice for you. If you take other medicines, are pregnant, or have a health condition, ask a pharmacist or doctor before starting.
• Best time of day: Timing follows what you want from it. People who use it for sleep usually take it in the evening. People who use it for daytime nerves spread it out, and risk feeling drowsy. Do not take it before driving or using machinery until you know how it affects you.
• With or without food: Food does not seem to matter much. Tea is normally drunk between meals or before bed. Capsules and tinctures can be taken with a little food if they upset your stomach. Do not take it with alcohol, which adds to the drowsiness.
• Time to effect: A calming effect, if it comes at all, is usually noticed within 30 to 60 minutes of a tea or tincture. Sleep studies that saw a change used daily tea for about a week. It may do nothing for you. The trials were small, and many people notice no difference.
• How long to take it: Most trials ran for one to four weeks, so nothing is known about long-term use. Traditional and label use is short-term, for a rough patch rather than for years. If anxiety or poor sleep lasts more than two to four weeks, see a doctor instead of carrying on with a herb.