Native Americans have another pearl in their ancient herbal pharmacy – passion flower. This plant has stunning flowers, delicious fruits, and a 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.
What is Passion Flower?
Over 500 different species of passionflower (Passiflora) belong to the Passifloraceae family of herbs. The most common ones include :
- Passiflora incarnata – purple passionflower
- Passiflora caerulea – blue passionflower
- Passiflora edulis – “passion fruit” or maracuja
- Passiflora foetida – “stinking” passionflower
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.
- Relieves anxiety
- Improves sleep quality
- Reduces menopausal symptoms
- May relieve substance dependence
- May help with attention disorders
- Clinical trials have notable caveats
- May cause weakness and digestive issues
- Interacts with psychoactive drugs
- Dangerous for pregnant women
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].
- Flavonoids: vitexin, isovitexin, apigenin, chrysin, orientin
- Indole alkaloids: harman, harmin, harmaline, harmol
- Phenolic acids: formic acid, butyric acid, GABA
- Fatty acids: linoleic, palmitic, oleic
- Cyanogenic glycosides
- Essential oils
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 .
Mechanism of Action
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].
- Relax the mind and protect the brain
- Soothe the lungs
- Boost metabolism and heart health
- Relieve pain and inflammation
Health Benefits of Passion Flower
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 .
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].
2) Menopausal Symptoms
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.
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 .
In one study on rats, however, passionflower had no effects on sleeping time or quality .
4) Substance Dependence (Addiction)
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.
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 .
5) Attention Deficit Hyperactivity Disorder (ADHD)
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 .
Animal and Cellular Research (Lacking Evidence)
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.
- Reduce the duration and severity of seizures
- Enhance the brain-protective effects of GABA
- Maintain normal levels of serotonin and noradrenaline
- Decrease post-seizure depression and mortality
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].
8) Brain Protection
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].
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].
Vitexin reduced post-surgery pain in mice via the same mechanisms but couldn’t prevent it .
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.
Limitations and Caveats
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 :
- Small sample size [12, 24, 13, 55]
- Invalid placebo [33, 13]
- Lack of details about the extract [1, 44, 19, 12]
- Unknown randomization technique [1, 12, 44, 19, 55]
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.
Passion Flower Side Effects & Precautions
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.
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].
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 .
Passion Flower Supplements
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:
- Anxiety: 1 – 2 ml/day (tincture) or 250 – 1,000 mg/day (dry extract) for 1 month, or before intervention [12, 19, 23, 25, 96]
- Sleep: 80 mg of the dry extract (+ other herbs) or 2 g of the dried herb for 1-2 weeks [36, 13]
- Opiate dependence: 3 ml (60 drops) of tincture daily for 2 weeks. Requires medical supervision 
- ADHD: 0.04 mg/kg of body weight for 2 months (children!) 
- Menopause: 3 ml (60 drops) of tincture daily for 6 weeks 
- Cough: 500 mg of dry extract before intervention 
Based on clinical data and traditional uses, the European Medicines Agency (EMA) suggests the following doses [91+]:
- Infusion (tea): 1 – 2 g of dried herb in 150 ml of boiling water, 1 – 4 times daily
- Powdered herb: 0.5 – 2 g, 1 – 4 times daily
- Liquid extract (tincture): 2 – 4 ml (40 – 80 drops) daily
How to Make Passion Flower Tea
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.
Combinations With Other Herbs
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:
- Anxiety and stress: with hawthorn, valerian, and ballota (calming herbs), along with cola and guarana (mild stimulants) 
- Insomnia and irritability: with kava, valerian, and hops [36, 97]
- Depression: with St. John’s Wort (Hypericum) 
However, these herbs may, in theory, enhance each other’s side effects due to similar mechanisms of action.
Passion Flower for Anxiety – Reviews
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.