Native Americans have another pearl in their ancient herbal pharmacy – passion flower. This plant has stunning flowers, delicious fruits, and calming effect, but clinical research has yet to cast more light on it. Read on to discover the benefits, dangers, and interesting facts about passion flower.
Over 500 different species of passionflower (Passiflora) belong to the Passifloraceae family of herbs. The most common ones include :
Most species are climbing vines while some grow as shrubs or small trees. In late spring, they bloom large and beautiful flowers which last only a day.
Spanish conquistadors named this unique flower after the “Passion of Christ“; they found a complex symbolism between the numbers of flower parts and certain events from the last days of Jesus’ life. The flower also resembles a clock, and many nations call it a “clock-flower.”
Passion flowers are native to Latin America, but they grow well in any tropical area. People cultivate them for their sensational flowers and delicious fruits.
People around the globe enjoy the fruit of Passiflora edulis, the famous “passion fruit” or maracuja. Native Americans also use dried leaves of passion flower for smoking.
Purple passionflower or maypop (Passiflora incarnata) has a long history of use in traditional medicine. This evergreen vine climbs up to 6 m and tolerates urban conditions, including roadsides and waste grounds.
Native Americans have used passionflower for insomnia, anxiety, seizures, pain, and more. The colonists adopted this calming herb and made it an essential remedy in European herbalism.
Other traditions have used passion flower to combat muscle cramps, asthma, and even cancer. Its relaxing properties are even more popular nowadays, as a promising solution for a stressful life and mental distractions [1, 2, 3].
Although we call it passion flower, the whole herb has medicinal value. The above-ground parts contain a wide range of bioactive components, such as [1, 4]:
Standardized passionflower (P. incarnata) extracts contain 3.5% or 7% of total flavonoids, expressed as vitexin or isovitexin .
Components and medicinal properties vary between the species. Passiflora edulis is famous for its sweet fruit, commonly called passion fruit, but it has weak therapeutic value .
Flavonoids from passionflower can combat inflammation and free-radical damage, prevent cell mutations, block pain signals, and more [5, 6, 7].
They also activate the GABA receptors in the brain, supporting relaxation and repair. The presence of GABA in passionflower enhances these effects [1, 8, 9].
Indole alkaloids may boost crucial neurotransmitters in the brain – dopamine, noradrenaline, serotonin – by blocking an enzyme that transforms them (MAO). This effect may protect against depression and other mental disorders [10, 11].
Note: All studies and health benefits refer to purple passionflower (Passiflora incarnata) unless stated otherwise. Clinical trials with passionflower, although promising, had notable design flaws we’ll cover in “Limitations and Caveats.”
Up to 13% of people in the US suffer from anxiety, making it the most common mental disorder. Conventional treatment comes with serious challenges, such as drug dependence .
In a clinical trial of 36 patients with general anxiety, passionflower extract (1-month treatment) was as effective as oxazepam, an anti-anxiety drug. What’s more, patients who took the herb performed better on their jobs .
In 30 patients, doctors added passionflower to standard treatment with an SSRI drug, sertraline. The patients’ symptoms improved without significant side effects .
In a larger clinical trial (182 patients), an herbal mixture with passion flower relieved anxiety in 43% of the patients (vs. 25% placebo). Other herbs likely contributed to the results .
Two reviews analyzed the data from 25+ clinical trials and suggested significant anti-anxiety effects of purple passionflower [21, 22].
Many people experience anxiety when facing surgery or dental procedure. According to clinical trials on 200+ patients, a short-term course of passionflower (Passiflora incarnata) extract can reduce anxiety in such cases [23, 24, 25, 26].
Scientists observed anti-anxiety effects of passionflower extract and its flavonoid, isovitexin, in lab animals [27, 28, 29, 8].
Women who enter menopause may experience a range of unpleasant symptoms due to hormonal changes. These range from flushes and headache to anger and depression .
Two reviews gathered data from 20+ clinical trials and concluded that purple passionflower (Passiflora incarnata) could ease common menopausal symptoms [31, 32].
In a clinical trial of 59 menopausal women, passionflower extract (3 ml a day for 6 weeks) relieved hot flushes, insomnia, and mood issues .
No valid clinical evidence supports the use of passion flower for any of the conditions in this section. Below is a summary of up-to-date animal studies, cell-based research, or low-quality clinical trials which should spark further investigation. However, you shouldn’t interpret them as supportive of any health benefit.
Anxiety and insomnia often go hand in hand. Conventional therapeutic strategies for insomnia are facing similar challenges, and most drugs aren’t suitable for long-term use .
According to a review of clinical trials, passionflower can help with restlessness and insomnia. However, most studies used combinations with other calming herbs, which likely contributed to the results .
In a clinical trial of 91 patients, an herbal product with passionflower (P. incarnata) extract boosted sleep quality and duration. It matched the effects of zolpidem, a common sleeping pill. The product also contained valerian and hops extracts .
Passionflower tea (1 cup daily for a week) helped 41 people with mild sleep disorders .
Scientists have also noticed sedative effects of passionflower in animal trials. The treated animals were less irritated and slept longer [37, 38, 39, 40].
In one study on rats, however, passionflower had no effects on sleeping time or quality .
Any substance that impacts mood – including tobacco, alcohol, street drugs, and medicines – can cause misuse and addiction, often with severe consequences .
According to preliminary research, flavonoids from passionflower (Passiflora incarnata) may help relieve dependence on :
In a clinical trial of 65 patients, passionflower extract (3 ml a day for 2 weeks) reduced the physical symptoms of opiate withdrawal. When added to clonidine (standard treatment), passionflower enhanced mental recovery by relieving anxiety, insomnia, and agitation .
In studies on rats, passionflower extract and its flavonoids could relieve nicotine dependence. They blocked the nicotine receptors and decreased withdrawal symptoms such as weight loss, stress, and depression [45, 46, 47].
In a preliminary clinical study of 32 alcohol abusers, a product with passion flower extract reduced excessive sweating and liver enzymes while improving appetite and quality of life. The mixture contained other ingredients, such as black seed, cocoa, and saffron extracts .
The lack of placebo control makes these results questionable.
In mice and rats, passionflower relieved anxiety and numbness due to alcohol withdrawal [49, 50].
Diazepam (Valium) and other benzodiazepines are sedative drugs that often cause tolerance and dependence after long-term treatment. Flavonoids from passionflower prevented diazepam dependence in mice [51, 52].
Keep in mind that passionflower extract can interact with benzodiazepines and other sedative drugs (more details in “Drug Interactions” below).
In mice, passionflower extract countered THC tolerance and reduced withdrawal symptoms .
ADHD is on the rise among children worldwide. Wrong diagnoses have partly contributed to the stats, but many children do need medical attention and proper treatment .
In a clinical trial of 34 children with ADHD, passionflower was as effective as methylphenidate (Ritalin). Children who took the herb experienced fewer side effects such as anxiety and reduced appetite. A small sample size questions the validity of these results .
A review of nine studies (450+ children) evaluated different herbs for ADHD and found low evidence for passionflower extract .
Uncontrolled coughing may hinder extubation (the removal of a breathing tube) and similar procedures. In one clinical trial (138 patients), treatment with 500 mg of passionflower extract prevented coughing and enabled extubation .
No clinical evidence supports the use of passion flower for any of the conditions listed in this section. Below is a summary of the existing animal and cell-based research, which should guide further investigational efforts. However, the studies listed below should not be interpreted as supportive of any health benefit.
In studies on rats and mice with epilepsy, researchers observed the potential of passionflower (P. incarnata) extract to [58, 59, 9, 40]:
Vitexin, a flavonoid from passionflower, strengthened the brain tissue and blocked inflammation in rats. As a result, it cut the risk of seizures. Another passionflower flavonoid, chrysin, protected mice against seizures and relaxed their muscles [60, 61].
In mice and rats, purple passionflower blocked free-radical brain damage, improving the animals’ cognition and movement. Another type of passionflower, P. cincinnata, prevented the progression of Parkinson’s disease in mice [62, 63].
Vitexin, apigenin, and chrysin (abundant in passionflower) have shown beneficial effects against Alzheimer’s and Parkinson’s disease in animal and cellular models studies by [64, 65, 66, 67, 68, 69, 70].
Passionflower contains indole alkaloids, which can boost the levels of essential neurotransmitters in the brain, such as dopamine, serotonin, and noradrenaline. This feature makes them promising candidates for the development of new antidepressants [10, 11].
Scientists examined the potential antidepressant effects of passionflower and its combination with St. John’s Wort in a couple of animal trials [71, 72].
A type of passionflower, famous for its “passion fruit” (P. edulis), relieved the symptoms of depression in mice by raising the levels of serotonin and dopamine [73, 74].
The lack of GABA in the brain may also trigger depression, especially in menopause. The stimulating effects of passionflower on GABA receptors might prevent these changes [75, 76, 9].
In diabetic mice, two types of passionflower (P. incarnata and P. suberosa) reduced blood glucose levels by enhancing metabolism. They also lowered blood lipids, cholesterol, and body weight [16, 77].
In other animal studies, scientists observed the potential antidiabetic effects of passionflower alkaloids: chrysin, vitexin, and isovitexin [78, 79, 80, 81, 82, 83].
Passionflower extract eased the pain due to injuries and impaired nerve function in rats. The herb activated GABA and opioid receptors, relaxing the nerves and blocking pain signals [17, 40].
Vitexin reduced post-surgery pain in mice via the same mechanisms but couldn’t prevent it .
Other species of passionflower (P. foetida and P. cincinnata) relieved pain and paw swelling in studies on rats and mice [85, 86, 87].
Once again, scientists observed the health effects from this section in animal studies only. In the lack of clinical research, we can’t draw any conclusions and make recommendations.
Passionflower has vast potential as an herbal remedy, but most of its health benefits lack stronger clinical evidence. The following limitations and caveats in the clinical trials prevent us from drawing reliable conclusions :
Additionally, many animal trials used pure flavonoids, not a passionflower extract. Well-designed clinical trials are needed to confirm the promising health benefits of this herb.
This list does not cover all possible side effects. Contact your doctor or pharmacist if you notice any other side effects. In the US, you may report side effects to the FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch. In Canada, you may report side effects to Health Canada at 1-866-234-2345.
Passionflower was safe in most clinical trials. In some people, it may cause [19, 13, 33, 36, 1, 3]:
The FDA proclaimed it safe for human consumption when used as a food additive .
One woman experienced severe vomiting, abnormal heart rhythm, and weakness after taking regular doses of passionflower for a few days. This report didn’t reveal the details about her condition or other drugs/supplements she was taking .
Doctors reported a case of an intense allergic reaction triggered by passionflower .
In clinical trials, children of different ages took passionflower and experienced no significant side effects. That said, experts don’t recommend it for children 3 – 12 years old without medical supervision [55, 56, 11, 91].
Pregnant women should avoid passionflower by all means. It may stimulate contractions and inflict severe damage on newborns [3, 92].
Herb-drug interactions can be dangerous and, in rare cases, even life-threatening. Always consult your doctor before supplementing and let them know about all drugs and supplements you are using or considering.
Passionflower has potent effects on the brain and may thus interact with psychoactive drugs, especially CNS depressants such as barbiturates (Nembutal, Luminal) and benzodiazepines (Ativan, Klonopin) [93, 12].
In one patient, combining valerian and passionflower with a sedative drug, lorazepam, caused handshaking, dizziness, and fatigue .
In theory, passionflower may have dangerous interactions with some antidepressants because its alkaloids increase the levels of serotonin and other neurotransmitters [10, 11, 95].
Passion flower supplements have not been approved by the FDA for medical use. In general, regulatory bodies aren’t assuring the quality, safety, and efficacy of supplements. Speak with your doctor before supplementing.
Different herbal mixtures for stress, anxiety, and sleep issues contain passionflower.
As a single herb, pills with dry passionflower extract (250 – 400 mg) are the most popular. Some products are standardized to 3.5% total flavonoids expressed as vitexin or isovitexin.
Tea bags (1 – 2 g of dried herb) and tinctures (liquid extracts) are also available.
The doses below used in clinical trials may not apply to you personally. If your doctor suggests using passion flower, work with them to find the optimal dosage according to your health condition and other factors.
The following doses showed the best results in clinical trials:
Based on clinical data and traditional uses, the European Medicines Agency (EMA) suggests the following doses [91+]:
If you have tea bags, just steep one tea bag in 150 ml of boiling water for 5 – 10 mins.
If you have loose tea (dried herb), measure up to 2 g (approx. 1 tablespoon) and use the same approach. For more details, see “Dosage” above.
Calming herbal mixtures are quite popular as herbs enhance each other’s effects and give better results. The following combinations proved efficient in clinical trials:
However, these herbs may, in theory, enhance each other’s side effects due to similar mechanisms of action.
The opinions expressed in this section are solely from the users who may or may not have a medical background. Their reviews do not represent the opinions of SelfHacked. SelfHacked does not endorse any specific product, service, or treatment.
Do not consider user experiences as medical advice. Never delay or disregard seeking professional medical advice from your doctor or another qualified healthcare provider because of something you have read on SelfHacked.
Most users take passion flower (alone or in different combinations) to relieve anxiety and sleep issues. A lot of them reported improved sleep quality, relaxation, increased productivity, and general wellbeing.
Some people, on the other hand, failed to achieve symptom relief and even experienced headaches, drowsiness, and digestive issues.
Many users complain about the poor product quality so make sure to buy from reliable sources.
Many passionflower species give beautiful flowers and delicious fruits, but only purple passionflower (Passiflora Incarnata) has well-documented health effects.
In traditional medicine, folks use passionflower to relieve anxiety, sleep issues, seizures, pain, and inflammation. Clinical trials have confirmed the potential benefits of passionflower for anxiety and menopausal symptoms. There’s insufficient evidence for sleep issues, attention disorders, and substance dependence.
Children between 3-12 years should take passionflower only under strict medical supervision. Pregnant women and allergic people should avoid it. To avoid potentially dangerous drug interactions, make sure to consult with your doctor before taking passionflower.
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