Passionflower (Passiflora incarnata) has a long history of traditional use for calming nerves and promoting relaxation, particularly in Native American and European herbal medicine. In recent years, its use for supporting stress reduction has gained scientific interest. Several clinical studies and systematic reviews have evaluated passionflower extracts for their anxiolytic (anxiety-reducing) and calming effects, which are closely related to stress relief.

The active constituents in passionflower, such as flavonoids and alkaloids, are thought to modulate the gamma-aminobutyric acid (GABA) system in the brain. This neurotransmitter system is involved in reducing neuronal excitability, which can lead to a calming effect and decreased stress perception. Small randomized controlled trials have demonstrated that passionflower extracts may reduce subjective anxiety and improve sleep quality, both of which are important for managing stress.

However, while there is promising evidence, most studies are small, of short duration, and sometimes lack rigorous methodology. Meta-analyses suggest a potential benefit, but also call for larger, well-designed clinical trials to confirm efficacy and determine optimal dosing. Overall, the use of passionflower for stress is supported by both traditional use and emerging scientific evidence, but the current scientific consensus rates the quality and quantity of evidence as moderate.