Herbal remedies are often sought for their natural benefits, and passion flower (Passiflora incarnata) is particularly known for its calming and sedative effects. While generally well-tolerated in many people, its safety depends heavily on the consumer's health status, dosage, and whether the correct species is used.
General safety and side effects
For the average, healthy adult, passion flower is considered "possibly safe" when consumed as a tea for up to seven nights or as a supplement for up to eight weeks. However, even at standard doses, some common side effects can occur:
- Drowsiness
- Dizziness
- Confusion
- Mental slowing
- Nausea and vomiting
- Allergic reactions (less common)
Because of its sedative properties, it is crucial to exercise caution when driving or operating heavy machinery until you are aware of how the herb affects you.
Critical contraindications and drug interactions
Certain individuals should avoid passion flower entirely, and everyone must be aware of its potential for serious drug interactions. Always consult a healthcare provider before starting any new herbal supplement, especially if you have pre-existing medical conditions or are on other medications.
Contraindications
- Pregnancy and Breastfeeding: Passion flower is considered "possibly unsafe" during pregnancy because some compounds may cause uterine contractions and potentially induce early labor. There is insufficient safety information regarding use during breastfeeding.
- Surgery: It is strongly recommended to stop using passion flower at least two weeks before any scheduled surgery. The herb can interact with anesthesia and other sedative medications, potentially slowing down the nervous system too much and causing excessive drowsiness or slowed breathing.
- Allergies: Anyone with a known allergy to passion flower or related plants should avoid it.
Drug interactions
Passion flower has been shown to interact with several types of medications, potentially increasing their effects:
- Sedative medications (CNS Depressants): The combination can cause excessive drowsiness and slowed breathing. This includes prescription medications like benzodiazepines (e.g., Ativan, Valium) and barbiturates.
- Anticoagulants (Blood Thinners): Passion flower might have a mild blood-thinning effect, increasing the risk of bleeding when taken with medications such as warfarin or aspirin.
- Antidepressants: Specific compounds in passion flower (harmala alkaloids) may interact with certain antidepressants, particularly older monoamine oxidase inhibitors (MAOIs).
- Herbal Combinations: Mixing passion flower with other sedating herbs like kava or valerian root can compound the effects and increase side effects.
Not all species are equal
It is vital to understand that not all passion flower species are safe for consumption. The medicinal properties are typically associated with Passiflora incarnata. Other species, such as the ornamental Blue Passionflower (Passiflora caerulea) and Stinking Passionflower (Passiflora foetida), contain cyanogenic glycosides in their leaves and unripe fruit. When ingested, these compounds can be converted into cyanide, a poison. Poisoning is not common because the toxic parts taste bitter, but it is a serious risk if the wrong species is used or prepared incorrectly. Ensure you are only consuming a product made from the verified, safe species.
Safety comparison: Passiflora incarnata vs. Cautions
| Aspect | Passiflora incarnata (Correct Use) |
Cautions & Considerations |
|---|---|---|
| General Safety | Considered likely safe for most healthy adults for short-term, moderate use (e.g., up to 8 weeks). | Safety is not well-established for long-term use. Individual reactions vary. |
| Side Effects | Mild drowsiness, dizziness, confusion are possible. | Higher doses can increase these effects and cause nausea, vomiting, or rapid heartbeat. |
| Drug Interactions | Generally safe with most common supplements, but interactions are possible. | Potential for serious interactions with sedatives, blood thinners, and antidepressants. |
| Pregnancy | Avoid. Not considered safe due to potential for uterine contractions. | Case reports suggest potential adverse outcomes; no controlled human trials exist. |
| Children | Possibly safe for short-term use in ages 6-13, but data is limited. | Generally not recommended for children under 12 without strict medical guidance. |
| Driving | Avoid until you know how it affects your alertness. | Sedative effects can impair judgment and reaction time. |
FDA regulation and product consistency
It is important to remember that dietary supplements, including passion flower, are not pre-approved by the U.S. Food and Drug Administration (FDA). Manufacturers are responsible for ensuring the safety and labeling of their products. This means product quality and potency can vary significantly between brands. To ensure you are consuming a safe and consistent product, choose reputable manufacturers and look for third-party certifications where available. You can read more about supplement safety and regulation on the National Center for Complementary and Integrative Health (NCCIH) website.
Conclusion
For most healthy adults, short-term consumption of the correct species of passion flower (Passiflora incarnata) is likely safe and can offer mild sedative effects for conditions like anxiety and insomnia. However, the herb is not without risk. Specific populations, including pregnant or breastfeeding women, children, and those on certain medications, should avoid its use. Serious interactions with sedatives, blood thinners, and anesthesia are a significant concern. Because of the varied quality of supplements and the existence of toxic species, responsible consumption involves a clear understanding of your personal health, the product you are using, and always consulting a healthcare professional before beginning use.
Safety Checklist
- Have you consulted a doctor, especially if you take other medications or have a health condition?
- Are you using a reputable, high-quality product made from Passiflora incarnata?
- Are you pregnant, breastfeeding, or planning for surgery in the next two weeks? If so, avoid passion flower.
- Are you aware of the potential for drowsiness and its impact on driving or operating machinery?
- Are you starting with a low dose to assess your body's reaction?
- Have you checked for interactions with all other medications, supplements, and alcohol?
- Are you avoiding using passion flower for long-term periods without medical advice?
