The passion flower, a genus of climbing vines known as Passiflora, has a long history of traditional use for promoting sleep and easing anxiety. The species most commonly used for this purpose is Passiflora incarnata, often called Maypop. While the plant is popular in the modern supplement market for its calming effects, understanding the potential drawbacks and risks is important. Concerns include common adverse reactions, dangerous drug interactions, species-specific toxicities, and horticultural challenges.
Common Side Effects of Consumption
Consumption of Passiflora incarnata can lead to several mild adverse reactions, mostly resulting from its intended calming properties. The most frequently reported effect is drowsiness, which is beneficial for sleep but can be problematic during waking hours. This sedative action is mediated by the plant’s interaction with the brain’s gamma-aminobutyric acid (GABA) system, enhancing its inhibitory effects.
Other reported side effects include dizziness, mental slowing, and mild gastrointestinal disturbances like nausea. These effects are often dose-dependent, becoming more pronounced as the amount consumed increases. In rare instances, individuals using higher doses, such as 800 mg of a dried alcoholic extract, have reported uncoordinated movement (ataxia) and confusion. The supplement is generally considered well-tolerated, with side effects resolving quickly upon discontinuation.
Drug and Health Condition Interactions
One significant safety concern involves passion flower’s potential to interact with other medications and certain health states. Because its active compounds modulate the central nervous system (CNS), taking it alongside other CNS depressants can lead to excessive sedation and cognitive impairment. This synergistic effect occurs with substances like alcohol, benzodiazepines, and sedative-hypnotic drugs. This combination may cause dangerously slowed breathing or profound sleepiness.
Special caution is necessary for individuals facing scheduled medical procedures. Passion flower should be discontinued at least two weeks before any planned surgery. Its CNS effects could dangerously increase the impact of anesthetic agents and other perioperative medications. Furthermore, the use of passion flower is generally contraindicated during pregnancy. Certain alkaloids, such as harman and harmaline, possess uterine stimulant action in animal studies, posing a theoretical risk of inducing contractions. Due to a lack of sufficient human safety data, its use is also advised against while nursing.
Cultivation and Growth Problems
Cultivating passion flower presents various horticultural challenges, often related to the plant’s vigorous growth habit and susceptibility to specific pathogens. In warmer climates, many Passiflora species, including those used as rootstock, can exhibit aggressive, vine-like behavior. This leads to invasive growth, where the plant sends out runners and suckers far from the original planting site, making it difficult to control and remove entirely.
The vines are susceptible to a range of diseases, including fungal infections like Brown Spot, caused by Alternaria passiflorae, which damages leaves and fruit. Septoria Blotch is another concern, leading to premature defoliation. Bacterial diseases, such as Bacterial Grease Spot, infect stems and fruit and can lead to the death of the vine. The plant also attracts various pests, including sucking insects like aphids and thrips, as well as spider mites, which damage the foliage and compromise fruit yield.
Species Specific Toxicity Concerns
A significant risk in passion flower supplements stems from the diversity of the Passiflora genus, which contains hundreds of species with varying chemical compositions. While P. incarnata is the standard medicinal species, many non-medicinal varieties contain cyanogenic glycosides. These compounds, such as gynocardin, are not toxic alone but metabolize into hydrogen cyanide when the plant’s cells are crushed or damaged.
This chemical defense mechanism is a natural deterrent against herbivores. It poses a toxicity risk to humans if the wrong species is harvested or consumed in high concentrations. The liberation of hydrogen cyanide occurs when the glycosides contact specific enzymes, which happens when the plant tissue is broken down. Consumers must source supplements from reliable vendors to ensure the product is derived exclusively from Passiflora incarnata and mitigate this risk.