Guide
How much passionflower should you take a day?
No health authority sets a single passionflower dose. The European Medicines Agency's monograph lists traditional-use ranges by form, and the two human trials that exist each tested one specific amount for one specific purpose.
There's no single dose of passionflower established for general use. The European Medicines Agency's herbal monograph lists traditional-use ranges by form, and the two human trials that exist each used one specific dose for one specific purpose — neither is a number to generalize from.
What the EMA's monograph lists
The European Medicines Agency's 2014 herbal monograph on Passiflora incarnata registers it as a traditional-use product "for relief of mild symptoms of mental stress and to aid sleep" — a category based on long-standing use, not a clinical dose-finding trial. Its listed adult ranges:
| Form | Single dose | Frequency |
|---|---|---|
| Herbal tea (infusion) | 1-2 g dried herb in 150 ml boiling water | 1-4 times daily |
| Powdered herb | 0.5-2 g | 1-4 times daily |
| Liquid extract (various concentrations) | 0.3-4 ml, depending on the specific extract | 3-5 times daily |
The monograph also directs that if symptoms persist beyond 2 weeks, a doctor or qualified health practitioner should be consulted, and that use in children under 12 isn't recommended because of a lack of data.
What the two human trials actually used
Outside that traditional-use registration, only two placebo-controlled human trials have tested passionflower at a specific dose, and neither is the basis for the monograph's ranges above:
- A 2008 trial gave adults a single 500 mg oral dose of Passiflora incarnata extract, once, 90 minutes before a medical procedure.
- A 2011 trial had healthy adults drink one cup of Passiflora incarnata herbal tea nightly for a week.
See passionflower benefits: what the research does and doesn't show for what each trial found. Neither compared different doses against each other, so neither tells you whether more or less would do something different.
Species and extract strength aren't interchangeable
Every number above is for Passiflora incarnata, prepared and standardized in a specific way. A different species — most notably Passiflora caerulea, also commonly sold — hasn't been dosed in the same research, so none of these figures transfer to it. A liquid extract's concentration also varies by its extraction ratio (the monograph lists several, from roughly 1:1 to 1:8), so "2 ml" of one product and "2 ml" of another aren't necessarily the same amount of herb — check the label for the ratio, covered in how to choose a good passionflower.
How much is too much
The EMA's traditional-use monograph states that no case of overdose has been reported to it. That's a narrower statement than "safe at any dose" — a published case report describes a woman hospitalized with nausea, vomiting, drowsiness and an abnormal heart rhythm after self-administering Passiflora incarnata at what she considered a therapeutic dose, with no exact amount recorded. There's no defined upper limit in the research to weigh a specific number against; following label directions, rather than taking more because a little seemed to help, is the reasonable read of that gap.
Questions people ask
How much passionflower should I take?
There's no dose established for general use. The EMA's monograph lists traditional-use ranges by form (above), and the two human trials that exist each tested one specific amount for one specific purpose — not a number to generalize from for something else.
How often can I take passionflower?
The EMA's monograph lists most forms as 1-4 times daily (liquid extracts up to 3-5 times, depending on concentration), based on traditional use rather than a trial that tested frequency directly.
Is there a difference between passionflower 250 mg and 500 mg?
Commercial capsules are commonly sold in that range. The one trial that used a specific extract amount gave 500 mg as a single dose for a specific, short-term purpose — not a general daily target, and not a head-to-head comparison of 250 mg against 500 mg.
What counts as a passionflower overdose?
There's no defined toxic dose in the research. The one published case of significant adverse effects came from a self-administered "therapeutic" dose, not an unusually large one — which is itself a reason to stick to label directions rather than assume more is safer.
Related reading: when is the best time to take passionflower?, passionflower side effects, and who should not take passionflower?.
Sources
- Preoperative oral Passiflora incarnata reduces anxiety in ambulatory surgery patients: a double-blind, placebo-controlled study A 2008 placebo-controlled trial found a single 500 mg dose of Passiflora incarnata extract, given 90 minutes before surgery, produced better anxiety scores in surgical patients than placebo, without added sedation or slower recovery.
- A double-blind, placebo-controlled investigation of the effects of Passiflora incarnata (passionflower) herbal tea on subjective sleep quality A 2011 placebo-controlled crossover trial found a week of nightly passionflower tea produced better self-rated sleep quality than a week of placebo tea in healthy adults with mild sleep complaints, based on sleep diaries.
- Toxicity of Passiflora incarnata L A published case report describes a woman hospitalized with nausea, vomiting, drowsiness and an abnormal heart rhythm after taking Passiflora incarnata at a self-described therapeutic dose.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.