Passionflower has a striking purple bloom and a long history as a calming herb. If you are looking at it for sleep, you probably want to know whether the research supports that use, and how much it takes. Here we look at what passionflower is and what the sleep studies found, compare tea and extracts, look at the amount in Sleep Harmony, and cover safety.
In this article
From Anirva, the maker of Sleep Harmony. This article is general information, not medical advice. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
- Passionflower has long been used as a sedative. It is a climbing vine native to the Americas. [1]
- The sleep research is small. A tea study found better self-rated sleep quality, and a sleep-lab study found a small rise in total sleep time. [4][5]
- European regulators recognize a traditional use. It is used to relieve mild stress and to aid sleep, based on long-standing use rather than strong trial evidence. [3]
- Sleep Harmony contains 50 mg of extract. The extract amounts in the studies we checked were not stated in their summaries. [6]
- It should not be used in pregnancy. It may also add to the effects of anesthesia and some sedating medicines. [1][2]
Facts at a glance
| Fact | Detail |
|---|---|
| Ingredient | Passionflower extract, aerial parts, standardized to 3.5% vitexins [6] |
| Amount in Sleep Harmony | 50 mg a day, in 2 capsules [6] |
| Amounts studied | Not stated in the study summaries we checked [4][5] |
| Kinds of evidence | One traditional-use monograph, one 1-week tea study, one 2-week sleep-lab study [3][4][5] |
| Last reviewed | [DATE] |
What Is Passionflower?
Passionflower (Passiflora incarnata) is a climbing vine native to the southeastern United States and Central and South America. [1] It is also known as maypop, apricot vine and passion vine. [2]
Traditionally, passionflower has been used as a sedative. [1] Spanish explorers brought it to Europe in the 16th century, where it became part of folk medicine. [1] Today, it is sold as tea, capsules and liquid extracts.
In Europe, the herbal medicines agency lists passionflower as a traditional herbal medicine for relief of mild stress and to aid sleep. [3] This status is based on at least 30 years of use, including 15 years in the European Union. [3] It is not based on strong clinical trial evidence. [3]
How Might Passionflower Work?
Passionflower contains plant compounds called flavonoids, including isovitexin, along with alkaloids, chrysin and maltol. [2] Sleep Harmony's passionflower extract is standardized to 3.5% vitexins, which are flavonoids of this kind. [6]
Memorial Sloan Kettering Cancer Center reports that some of these compounds are thought to act on GABA, a calming messenger in the brain. [2] These ideas come mainly from laboratory research. They help explain why passionflower is studied for sleep, but they do not show that it improves sleep in people.
What Does the Research Show?
The research on passionflower and sleep is still growing. NCCIH says a small amount of research suggests passionflower might improve total sleep time in adults with insomnia. [1] Its effects on falling asleep and staying asleep are mixed. [1]
A tea study in healthy young adults
This 2011 study included 41 healthy adults aged 18 to 35. [4] Each person drank passionflower tea for one week and a placebo tea for another week, with a break in between. [4] Neither the participants nor the researchers knew which tea was which. [4]
People rated their sleep quality as better during the passionflower week. [4] Memorial Sloan Kettering describes this as a short-term benefit from a low-dose tea. [2] The researchers noted that the people in this study had mild ups and downs in their sleep. [4]
A sleep-lab study in adults with sleep problems
This 2020 study included 110 adults with long-term sleep problems, with an average age of about 40. [5] They took passionflower extract or a placebo for two weeks, then spent a night in a sleep lab. [5]
Total sleep time rose more in the passionflower group than in the placebo group, by a small but statistically significant margin. [5] Sleep efficiency and time awake during the night improved in the passionflower group. However, these changes were not different from placebo. [5] The researchers said more study is needed. [5]
Study summary
| Study | People | Amount | Length | Main Result |
|---|---|---|---|---|
| Ngan & Conduit, 2011 [4] | 41 healthy adults, 18–35 | Low-dose tea | 1 week each (crossover) | Better self-rated sleep quality vs. placebo tea. |
| Lee et al., 2020 [5] | 110 adults with sleep problems | Extract (amount not in summary) | 2 weeks | Total sleep time rose more than with placebo; other sleep-lab measures not different. |
Tea or Extract: How Do the Amounts Compare?
The two main sleep studies used different forms. The 2011 study used a tea, and the 2020 study used an extract in capsules. [4][5] The study summaries we checked did not give the exact amounts, so the two forms are hard to compare.
NCCIH notes that passionflower may be safe as a tea for up to 7 nights, and as a daily extract for up to 8 weeks. [1]
How Much Passionflower Is in Sleep Harmony Compared With the Studies?
We could not confirm the study amounts, so we cannot say whether Sleep Harmony's 50 mg is higher or lower. The studies tested passionflower on its own, so their results do not describe Sleep Harmony.
| Source | Passionflower | Notes |
|---|---|---|
| Sleep Harmony (2 capsules) | 50 mg extract | Aerial parts, 3.5% vitexins [6] |
| Tea study | Low-dose tea | Amount per cup not in summary [4] |
| Sleep-lab study | Extract | Amount not in summary [5] |
14 ingredients, including 50 mg of passionflower extract
Sleep Harmony is a nightly two-capsule supplement that pairs passionflower with melatonin, magnesium, L-theanine, ashwagandha, valerian and three probiotics. Every ingredient is listed on the label.
See Sleep HarmonySafety and Interactions
NCCIH considers passionflower likely safe as a flavoring in food. [1] Possible side effects include drowsiness, dizziness and confusion. [1] The European agency had received no reports of side effects at the time of its assessment. [3]
Passionflower should not be used during pregnancy, as it may cause contractions of the uterus. [1] It might interact with some anesthesia medicines. [1] NCCIH suggests talking with your health care provider if you take passionflower within 2 weeks of a planned surgery. [1]
Memorial Sloan Kettering notes that passionflower may add to the effects of some sedating medicines. [2] It may also add to the heart-rhythm effects of medicines that affect the QT interval. [2]
Passionflower Is One Part of Sleep Harmony
Sleep Harmony combines melatonin, calming herbs and three probiotics in one formula. We chose ingredients that have each been studied for relaxation and sleep. Passionflower is one of them.
Sleep Harmony has not been clinically tested as a finished product. For this reason, we cannot say how its ingredients work together. The studies in this article tested passionflower by itself, and their results describe passionflower alone.
If you take Sleep Harmony, you are not relying on passionflower alone. It is one of 14 ingredients in each serving.
- The European agency had received no reports of side effects from passionflower medicines at the time of its assessment. [3] It can cause drowsiness or dizziness. [1]
- Passionflower should not be used during pregnancy, and it may interact with anesthesia and some sedating medicines. [1][2]
- If you take medicines or have surgery planned, a doctor or pharmacist can help you decide.
If You Are Deciding
Passionflower has a long traditional history, and a small amount of research supports it for sleep. Cleveland Clinic suggests a steady sleep schedule, less caffeine and alcohol, and a cool, dark bedroom. [7]
If you would like to try Sleep Harmony, the directions are two capsules 30 to 60 minutes before bedtime. [6]
The Short Version
Passionflower is a climbing vine with a long history as a calming herb. A tea study found better self-rated sleep quality, and a sleep-lab study found a small rise in total sleep time. The research is small and short. Sleep Harmony contains 50 mg of extract, alongside 13 other ingredients.
Frequently Asked Questions
Does passionflower help you sleep?
How much passionflower is used for sleep?
Is passionflower tea good for sleep?
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Does passionflower help with stress?
How is passionflower different from melatonin?
What are the side effects of passionflower?
References
- National Center for Complementary and Integrative Health. Passionflower. Last updated April 2025. https://www.nccih.nih.gov/health/passionflower
- Memorial Sloan Kettering Cancer Center. About Herbs: Passionflower. Last updated April 13, 2023. https://www.mskcc.org/cancer-care/integrative-medicine/herbs/passionflower
- European Medicines Agency. Passiflorae herba (passion flower): herbal medicine summary for the public. https://www.ema.europa.eu/en/medicines/herbal/passiflorae-herba
- Ngan A, Conduit R. A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality. Phytother Res. 2011;25(8):1153–1159. doi:10.1002/ptr.3400.
- Lee J, et al. Effects of Passiflora incarnata Linnaeus on polysomnographic sleep parameters in subjects with insomnia disorder: a double-blind randomized placebo-controlled study. Int Clin Psychopharmacol. 2020;35(1):29–35. doi:10.1097/YIC.0000000000000291. PMID: 31714321.
- Anirva. Sleep Harmony with Probiotics: Supplement Facts label and product page. https://anirva.com/products/sleep-harmony (accessed September 30, 2026).
- Umeda N (expert). Does magnesium help you sleep better? Cleveland Clinic Health Essentials. September 4, 2026. https://health.clevelandclinic.org/does-magnesium-help-you-sleep/
