Evidence Level
Moderate
Passionflower has moderate clinical evidence for both anxiety and sleep. Akhondzadeh et al. (2001) provided the most impactful evidence by demonstrating equivalence to oxazepam for GAD in a double-blind RCT. Movafegh et al. (2008) extended these findings to preoperative anxiety. Ngan & Conduit (2011) showed sleep benefits with passionflower tea in a crossover design. Appel et al. (2011) conducted a large multicenter observational study (n=425) with a combination product containing passionflower, confirming tolerability and efficacy for nervous restlessness and insomnia. The GABAergic mechanism is well characterized through in vitro and animal studies showing chrysin and related flavonoids bind GABA-A benzodiazepine sites.