A voice for
herbal medicine

We share traditional, scientific and practical insights written by experienced herbalists and health experts from the world of herbal medicine and natural health

← Back to Insights

Research seed: Passionflower

In this article, we discuss Passionflower in the treatment of generalized anxiety: A pilot double‐blind randomized controlled trial with oxazepam

Research seed passionflower
Passionflower tea (Passiflora incarnata)

Plant name and species

Passionflower (Passiflora incarnata)

Aim of study

Passionflower is traditionally used for anxiety. This study investigated the efficacy of passionflower for generalized anxiety disorder (GAD) in comparison with oxazepam.

Study method

The study was a double-blind randomized trial conducted on 36 out-patients diagnosed with GAD using the Diagnostic and Statistical Manual of Mental Disorders criteria. Patients were allocated randomly into groups, 18 with passionflower (45 drops a day) plus a placebo tablet and 18 with oxazepam 30mg plus placebo drops for a 4-week trial.

Results of study

Both the passionflower and oxazepam were effective in the treatment of GAD, and no significant difference was observed between the two. Oxazepam worked faster, however patients had more side effects such as dizziness, drowsiness and confusion which effected their job performance.


Both medicines work via GABA neurotransmitter systems. GABA neurotransmitters are there to make us relax, (much like serotonin is there to make us feel happy amongst other things).  Too much GABA however can lead to sedation, dizziness, loss of control of movement and confusion. This then stops our ability to communicate and work which can perpetuate further stress and anxiety. Although passionflower took longer to work, it was just as effective and does not cause the same side effects as oxazepam which can mean that passionflower is a better option for long-term mental health care. According to the BNF common or very common side effects of benzodiazepines (in which oxazepam is classed) include depression, fatigue; headache, muscle weakness, nausea; respiratory sleep disorders and withdrawal syndrome amongst other issues. On the contrary passionflower has a nervine action and is nutritive for the nervous system with a great safety profile.


Passionflower and oxazepam work equally well. Passionflower takes longer to work but does not have the same side effects of oxazepam (which can then perpetuate more anxiety). Medicines for mental health work best along with other types of self-care and support (for example exercise and therapy), however passionflower and other herbal medicines can provide helpful symptom relief and nourishment.

Sign up to our Newsletter

Sign up to our newsletter to receive the very latest in herbal insights.

Sign up to our newsletter