Passionflower: Everything You Need to Know

Trang Tran, PharmD
·8 min read
1

Known for alleviating anxiety and promoting sleep.

Medically reviewed by Allison Herries, RDN

Passionflower (Passiflora incarnata) is a climbing vine native to the southeastern United States and Central and South America. Native Americans used passionflower as a remedy for sleep and anxiety.

According to a test-tube study, the sedative effect of passionflower is attributed to its ability to increase the levels of the inhibitory neurotransmitter (chemical messenger) called gamma-aminobutyric acid (GABA).

This article discusses the potential uses of passionflower. It also covers the side effects and risks of taking passionflower supplements.

What Are Passionflower's Uses?



Explainer

Supplement use should be individualized and vetted by a healthcare professional, such as a registered dietitian nutritionist (RD or RDN), pharmacist, or healthcare provider. No supplement is intended to treat, cure, or prevent disease.



Passionflower has been studied in the settings of anxiety, sleep, and attention deficit hyperactivity disorder (ADHD).

Anxiety

Passionflower water extract at a dose of 700 milligrams (mg) per every 5 milliliters (mL) has been shown to reduce anxiety before surgery (that is, before spinal anesthesia) without changing the sedation (sleepiness) level.

Moreover, the premedication of passionflower 500 mg tablet was more effective than oxazepam at lowering anxiety before surgery. However, further research on using passionflower for presurgical anxiety is needed.



Explainer

Two to three weeks before surgery, let your surgical team know what herbal medicines or other supplements you take. This will help prevent complications like increased bleeding risk or, in the case of passionflower, complications with anesthesia.



In a study of 40 dental surgery participants with an average age of 18 to 28 years, a 260 mg passionflower pill taken by mouth 30 minutes before dental surgery reduced anxiety, blood pressure, and heart rate. Such effects were similar to those of midazolam 15 mg pill taken by mouth 30 minutes before surgery but with fewer cognitively impairing side effects.

It is important to note that the study samples consisted of more people assigned female than male at birth and thus may not apply to the general population.

A similar study was conducted on 200 participants aged 19 to 32 years who required extraction of their third molar. Taking passionflower capsules of 500 mg by mouth 60 minutes before surgery was shown to be just as effective as taking a 15 mg midazolam capsule 60 minutes before surgery.

The researchers concluded that passionflower may be an alternative to benzodiazepines for controlling anxiety in third-molar extractions.

One limitation of the study is that it did not assess the incidence of anterograde amnesia (an inability to form new memories) and other side effects using passionflower.

Further studies with larger sample sizes and more balanced baseline characteristics are needed.

Sleep

One study evaluating the effect of drinking 250 mL of passionflower herbal tea in the evening for seven days found a significant improvement in reported sleep quality. However, the researchers noted that passionflower may have a limited impact on sleep quality in people with low anxiety levels.

A two-week clinical trial conducted a sleep study in 84 participants between 30 and 52 years old. It showed that a 60 mg passionflower extract capsule improved sleep compared to a placebo (a treatment with no active properties) in subjects with insomnia disorder.

However, a longer treatment duration is needed to evaluate the risk of tolerance and dependence on passionflower. And since the dose used in the clinical trial was low, further studies investigating the different doses of passionflower would be needed.

Moreover, further studies directly comparing passionflower with conventional sleep medications are warranted to confirm its effectiveness in treating insomnia.

Attention Deficit Hyperactivity Disorder

In a study of 34 children between 6 and 13 years old, passionflower tablets and methylphenidate (the active ingredient in the brand Ritalin) for ADHD both showed clinical benefits based on a standardized rating scale parents and teachers used over an eight-week period.

Although promising, results from larger studies are needed to confirm the therapeutic effect of passionflower for ADHD.

<p>Bisstefano5 / Getty Images</p> Passionflower

Bisstefano5 / Getty Images

Passionflower

What Are Passionflower's Side Effects?

Your provider may recommend you take passionflower for specific reasons. However, taking a supplement like passionflower may have potential side effects.

These side effects may be common and mild or uncommon and severe.

Common Side Effects

Based on results from clinical studies, passionflower is generally well tolerated. However, the most commonly reported side effect is drowsiness. Other side effects include muscle relaxation and dizziness.

Furthermore, the sedative effects of passionflower have been reported to be dose-dependent. Dose-dependent means that when more passionflower is used, the more sedation it causes.

Severe Side Effects

No serious side effects occurred during the study evaluating the effect of passionflower in insomnia disorder and ADHD.

Additionally, no side effects, including memory loss or a decline in psychomotor functions, have been linked to passionflower.

Unlike benzodiazepines, a type of depressant drug, passionflower does not cause respiratory depression (slow, shallow breathing).

If you're having a severe allergic reaction or if any of your symptoms feel life-threatening, call 911 and get medical help right away.

What Are the Risks of Taking Passionflower?

While it is unknown whether it is safe to use passionflower during breastfeeding, passionflower should not be used during pregnancy due to the risk of uterine contraction.

Dried alcoholic extract of passionflower at a dose of 800 mg daily for up to eight weeks was shown to be safe. However, such a dose may cause drowsiness, confusion, and ataxia (uncoordinated movement) in some people. In general, avoid herbal preparations using alcohol during pregnancy.

Taking passionflower with alcohol or sedatives (medications that cause sleepiness) may increase drowsiness.

Listed below are some medications that can cause drowsiness:

Additionally, passionflower has been reported to cause QT prolongation (a condition that causes irregular heartbeat).

Listed below are some medications that can cause QT prolongation:

Passionflower may increase your risk of bleeding. Therefore, caution should be taken if you take blood thinners, such as Plavix (clopidogrel), Jantoven (warfarin), and aspirin.

Please consult with your healthcare provider before using passionflower.

Dosage



Explainer

Always speak with a healthcare provider before taking a supplement to ensure that the supplement and dosage are appropriate for your individual needs.



Commercially available passionflower products mostly contain 250 to 900 mg of passionflower. The therapeutic dose of passionflower has been reported to be 500 to 1,000 mg three times daily.

For anxiety before spinal anesthesia: The dose of passionflower syrup used in the clinical trial was 700 mg/5 mL given by mouth 30 minutes before anesthesia.

For anxiety before outpatient surgery: The dose of passionflower used in the study was 500 mg tablet given by mouth 120 minutes before surgery.

For anxiety before dental surgery: The dose used in the study was a 260 mg passionflower pill given by mouth 30 minutes before dental surgery. Another study used a dose of passionflower 500 mg capsule given by mouth 60 minutes before the third-molar tooth extraction.

For sleep: The dose used in the clinical trial was 250 mL of passionflower herbal tea, given in the evening for seven days.

For ADHD: A systematic review included a study that used passionflower tablets at a dose of 0.04 mg per kilogram (kg) of body weight (mg/kg) per day (twice daily) for eight weeks.



Explainer

Dietary supplements are not regulated like prescription medications in the United States. Therefore, some may be safer than others. When choosing a supplement, consider factors such as third-party testing, potential drug interactions, and other safety concerns. Talk to a healthcare provider or a registered dietitian nutritionist (RD or RDN) about supplement quality and safety.



Summary

Passionflower exhibits therapeutic potential in alleviating anxiety before surgery (i.e., spinal anesthesia, outpatient surgery, and dental surgery), promoting sleep, and improving ADHD. However, more rigorous clinical trials are needed to confirm such findings.

Passionflower can cause drowsiness and irregular heart rate. Therefore, it should not be taken with other medications or supplements that cause drowsiness or irregular heart rate.

Consult your healthcare provider before starting passionflower supplements, especially if you take certain medications or are breastfeeding or pregnant.

Frequently Asked Questions

What is passionflower good for?

Passionflower was just as effective as midazolam (a type of benzodiazepine) in reducing anxiety before dental surgery, with the added benefit of having fewer side effects associated with cognitive impairment compared to benzodiazepines.

Low doses of passionflower have been shown to improve sleep compared to a placebo (inactive treatment) in people with insomnia disorder.

Is passionflower safe?

Passionflower can cause drowsiness, confusion, and uncoordinated movement. Thus, it is advised to avoid using passionflower when drinking alcohol and taking medications that cause drowsiness.

However, no serious side effects, such as memory loss, a decline in psychomotor functions, and respiratory depression, were reported in the clinical studies.

Who should not take passionflower?

You should not take passionflower if you are pregnant or breastfeeding.

Exercise caution when using passionflower if you also take medications such as antiarrhythmics, antibiotics, antihistamines, benzodiazepines, blood thinners, opioids, tricyclic antidepressants, among many others.

This is not an exhaustive list. Please contact your pharmacist, registered dietitian nutritionist, or healthcare provider for more information about possible drug interactions.

Read the original article on Verywell Health.