How we rate
“Strong” = several concordant meta-analyses or systematic reviews. “Moderate” = one synthesis, or several controlled trials. “Limited” = early trials only. The rating is about the quality of the studies, not about how useful the supplement is.
Passionflower
Calming plant: in small trials, less anxiety before surgery or dental care, with an effect close to an anxiolytic, and slightly better sleep; the Cochrane review considers the trials too few to draw conclusions.
Benefits
- Anxiety before surgery: in 60 patients, 500 mg of passionflower taken 90 minutes before outpatient surgery gave lower anxiety scores than placebo, without sedation or delayed discharge. Before spinal anesthesia, in 60 patients, it prevented anxiety from rising.
- Dental care: in 63 anxious patients, the anxiety score went from 12.09 to 8.47 with passionflower drops, compared to 12.00 to 10.52 under placebo. In another trial (54 patients), anxiety dropped during wisdom tooth extraction, unlike placebo.
- As much as midazolam: in 200 patients before wisdom tooth extraction, 500 mg of passionflower had an effect similar to 15 mg of midazolam, whereas placebo did not control anxiety.
- Without memory blanks: in a trial on 40 patients, 20% remembered nothing under midazolam, whereas 260 mg of passionflower, for a similar anxiolytic effect, hardly affected memory at all.
- Generalized anxiety disorder: in 36 patients, 45 drops per day for 4 weeks performed as well as 30 mg of oxazepam, with less impairment at work; oxazepam acted faster.
- Sleep: in 110 insomniac adults, 2 weeks of extract lengthened total sleep time measured in the laboratory more than placebo; one week of herbal tea improved perceived sleep quality in 41 young adults.
- Stress: in 65 stressed and insomniac people, 30 days of extract at bedtime reduced perceived stress and lengthened sleep time compared to placebo.
- Withdrawal: in 186 patients followed up afterwards, adding passionflower during dose reduction more often allowed halving or stopping benzodiazepines, at 1 and 3 months; in 65 people withdrawing from opioids, added to clonidine, it better relieved psychological symptoms.
Precautions
Pregnancy: no reliable data in pregnant women; in five pregnant women treated for depression or anxiety who took it, one neonatal death and several complications were observed, and the authors request monitoring. If pregnant, do not take it without medical advice. Sedatives: passionflower has been compared to midazolam, oxazepam and melatonin, and given during the tapering of benzodiazepines, but no trial measures the outcome of their combination: if you are taking a sedative, speak to your doctor. Antidepressants: a single small trial (30 patients) added it to sertraline, with few adverse effects; if you are taking an antidepressant, ask your doctor's advice. Adverse effects: less drowsiness, muscle relaxation and dizziness than with midazolam in 20 patients; in a trial on 30 patients, higher diastolic blood pressure in the passionflower group. Warning: before surgery, 1,000 mg of passionflower impaired a cognitive test more than 6 mg of melatonin, in 52 patients. Limitations: too few trials: the Cochrane review found only two (198 participants) and considers them too few to conclude on anxiety. No clear effect in the large comparison: in a network meta-analysis of 29 trials, passionflower does not significantly reduce the Hamilton anxiety score. Less useful if anxiety is mild, according to the systematic review of nine trials. Small and short trials, from 20 to 200 patients; the study on benzodiazepines is not a randomized trial but a retrospective study.
Recommended dosage
500 mg of extract 60 to 90 minutes before a procedure; 45 drops per day over 4 weeks for anxiety; one cup of herbal tea per day (sleep).
How to take it
- For whom: trials involve patients before surgery or dental care, anxious, stressed or insomniac individuals; none involve athletes.
- Before a procedure: 260 mg 30 minutes before, 500 mg 60 to 90 minutes before, or 1,000 mg one hour before, depending on the trials.
- Long-term anxiety: 45 drops of extract per day for 4 weeks; 15 drops three times a day in addition to sertraline for one month in another trial.
- Sleep: one cup of herbal tea per day for one week, or an extract for 2 weeks; against stress and insomnia, an extract at bedtime for 30 days.
- Duration: the nine trials in the systematic review last from one day to 30 days; nothing indicates what a longer intake yields.
- Not every time: in 30 patients before wisdom tooth extraction, felt anxiety did not drop more than under placebo; only salivary cortisol dropped.
Did you know?
Before wisdom tooth extraction, 20% of patients under midazolam remembered nothing; under passionflower, for a similar anxiolytic effect, memory was hardly affected.
What the studies say
This Bayesian network meta-analysis compared the efficacy of 12 medicinal plants for the treatment of anxiety in adults. Silexan showed a significant effect on anxiety reduction, with possible benefits on depression and insomnia. Although other herbs were also studied, Silexan stands out for its significant effect and good tolerability, comparable to the control groups.
Zhang W, Yan Y, Wu Y, Yang H, Zhu P, Yan F, Zhao R, Tian P, Wang T, Fan Q, Su Z. — Pharmacological research (2022) — View the source study
For information only: not a substitute for medical advice. Dietary supplements are not a replacement for a varied, balanced diet. Learn more