Passionflower for inner restlessness and anxiety: gentle, but not a panacea

It is Sunday evening. Tomorrow is the conversation you have been dreading for days. You are sitting on the sofa, and yet your heart is pounding as if you were running.

Passionflower is one of the best-known plants for nervousness. It feels gentle, familiar and a bit like taking things into your own hands. I understand that well. The only question is: what can it do, and what can it not do?

I want to look beyond the plant here. Anxiety does not arise only in the head. Your nervous system, immune system, gut and nutrients might together turn the volume dial of your inner alarm. It is exactly this connection that I feel gets too little attention in many texts about herbs for anxiety.

Inner restlessness or anxiety disorder: where is the line?

You know restlessness. Before an exam, after an argument, in a week with too many appointments. But perhaps you also know the other kind: an anxiety that comes without a clear reason, that stays and makes your everyday life smaller, piece by piece.

This distinction is not a label. It decides which kind of help is right for you.

A team led by Bandelow at the University Medical Center Göttingen summarised the revised German guideline on anxiety disorders. A total of 35 experts from 29 professional societies and self-help organisations worked on it. There, cognitive behavioural therapy is considered the psychological treatment with the highest level of evidence. As first-choice medications, the guideline names certain antidepressants from the SSRI and SNRI groups. According to this summary, herbal remedies are not among the first choices.

If you are already taking medication for anxiety, please do not stop it on your own, not even in favour of a plant. Sedatives from the benzodiazepine group in particular should only be reduced with medical support. You can read what a supported withdrawal from sleeping pills can look like in Stopping sleeping pills.

Anthroposophic medicine describes anxiety as something that seizes thinking, feeling and willing all at once. This is a view from tradition, not a study result. I still find it helpful, because it shifts the focus from the single symptom to the whole person.

And now you know why the first question is not which plant you take, but which kind of anxiety you are experiencing.

What is passionflower, and what does the EU monograph say?

Perhaps you have seen a passionflower in bloom. The flower looks like a small work of art: a ring of fine filaments around a centre, almost like a halo of rays. The medicine, however, has little to do with this beauty.

What is used as medicine is the herb of Passiflora incarnata, meaning the parts above ground, sometimes with flowers or fruits. According to the assessment report of the European Medicines Agency (EMA), it mainly contains flavonoids, such as isovitexin and isoorientin. Certain alkaloids, the beta-carbolines, occur at most in traces and cannot be detected in most commercial products.

In 2014, the EMA’s Committee on Herbal Medicinal Products adopted the revised EU monograph. Under this monograph, passionflower is considered a traditional herbal medicinal product for the relief of mild symptoms of mental stress and as an aid to falling asleep. The monograph states that this classification is based exclusively on long-standing use.

Two points about this assessment matter to me. First: traditional means used for a long time and plausible, but not clinically proven. Second: the committee considered the available studies too weak to recognise efficacy. In its view, all studies suffered from serious shortcomings, such as too few participants, unclearly described products or inadequate statistical analysis.

In 2025, the EMA called for new scientific data to be submitted for a routine review of the monograph. Until a new version is available, the 2014 version applies.

And now you know why many packs speak of traditional use and not of a clinically proven effect.

How might passionflower act on the nervous system?

When anxiety comes, it feels as if someone has pushed the accelerator to the floor. Your heart beats faster, your breathing becomes shallow, your thoughts race. Is there a brake?

Yes, and it is called GABA. Gamma-aminobutyric acid is the most important inhibitory messenger in your brain. When it docks onto its receptor, a nerve cell becomes harder to excite. Imagine GABA as a dimmer that turns the light in your brain down a little.

Many anti-anxiety medications, such as benzodiazepines, strengthen exactly this dimmer. For passionflower, there are indications that it might also act on the GABA system. However, these indications come from the lab and from animal experiments.

In its assessment report, the EMA draws a sober conclusion. The mechanism of action is considered unclear, but more recent studies point to involvement of the GABA system. A substance long discussed as the main active ingredient, a so-called benzoflavone, could hardly be detected, or not at all, in later analyses of plants of different origins. In addition, the EMA considered the doses in the animal experiments high compared with what people take in with a product.

And now you know why two products with the same plant name can feel so different.

What do studies on passionflower for anxiety show?

Mechanisms are fascinating. But what you actually want to know is something else: will I notice anything when I am tense? That requires studies in humans.

Before the procedure: anxiety with an expiry date

The picture is similar in dental surgery. In a Brazilian study led by Dantas, 40 volunteers received passionflower on one occasion and the sedative midazolam on another before the removal of their lower wisdom teeth. With both, more than 70 per cent felt calm or only a little anxious. With midazolam, 20 per cent remembered nothing at all, while passionflower affected memory little or not at all.

In generalised anxiety: one small study and a lot of criticism

What the reviews say

Incidentally, in the same network analysis, saffron and L-theanine also showed no significant effect on anxiety in the overall analysis. You can read what saffron may show for low mood in Saffron for low mood, and my assessment of L-theanine in L-theanine for stress and sleep.

And now you know why I see passionflower more as a companion for restless phases and not as an answer to an anxiety that has stayed for months.

The nerve-immune lens: can inflammation intensify anxiety?

Do you remember your last proper infection? Perhaps you were not only tired, but also thin-skinned, irritable and quicker to worry. That might be more than your imagination.

Your immune system talks to your brain. Its messengers, the cytokines, are like radio signals. They not only reach the immune cells, but can also influence mood and alertness.

A team led by Michopoulos at Emory University in Atlanta describes a possible cycle. In anxiety disorders, the sympathetic nervous system is often revved up and its calming counterpart, the parasympathetic nervous system, is dampened. This might fuel inflammation. Inflammatory signals might in turn reach brain regions that regulate fear and anxiety, such as the amygdala.

From the perspective of clinical psychoneuroimmunology, KPNI for short, anxiety is therefore not purely a matter of the head. Your nervous system, hormones, immune system and metabolism negotiate together how loud your inner alarm sounds.

Where does passionflower stand in this picture? Based on current knowledge, if it acts at all, it acts on the brake in the nervous system. I am not aware of robust human data showing that it changes the inflammatory pathway in anxiety. That is why, with persistent anxiety, I look not only at the brake, but also at what might be fuelling the alarm from below.

I describe in more detail how inflammation and mood can be connected in Depression and inflammation. You can read how to interpret inflammatory markers such as hs-CRP in Silent inflammation.

And now you know why, with persistent anxiety, I also ask about infections, inflammatory markers and your digestion.

The gut-brain axis: what does your gut have to do with your anxiety?

A queasy feeling before the presentation. Diarrhoea before the exam. A knot in your stomach when the phone rings. Your gut often reacts to anxiety faster than your head.

Between your gut and your brain runs a kind of data line, the gut-brain axis. One important strand is the vagus nerve, a long nerve running from the brainstem down into the abdomen. Added to this are immune signals and substances that your gut bacteria produce themselves.

Gut bacteria can even produce GABA themselves. A team led by Strandwitz at Northeastern University in Boston found that bacteria of the genus Bacteroides in particular produce large amounts of GABA. In stool samples from healthy people, the corresponding metabolic pathways were active. In people with depression, a lower proportion of Bacteroides went hand in hand with brain activity patterns associated with depression. However, this does not show whether bacterial GABA reaches your brain directly.

A team led by Simpson at the University of Melbourne summarised 26 studies on gut flora in anxiety and depression, including only two comparative studies on generalised anxiety disorder. The diversity of the gut flora did not differ consistently. What stood out, however, were more pro-inflammatory bacterial species and fewer bacteria that produce short-chain fatty acids. These bacteria might communicate with the brain via inflammatory signals. According to the team, future studies need to take diet and medication into better account.

And passionflower? In 2023, a team from the Microbiota Lab at the Medical University of Warsaw looked at medicinal plants for anxiety and depression through the lens of the gut-brain axis, including St John’s wort, valerian, lavender and passionflower. According to the team, plant extracts can change the composition of the gut flora. Some substances that bacteria produce from plant constituents eased depression-like behaviour in animal models. At the same time, the team emphasises a large research gap. I am not aware of any human studies that have examined the influence of passionflower on the gut flora in anxiety.

You can read how the microbiome may be connected to mood in Depression and the gut-brain axis. How herbs themselves might influence the gut flora, in Medicinal plants and the gut. What fermented foods can contribute, in Fermented foods, and how the vagus nerve can be engaged in everyday life, in The gut-brain axis and vagus stimulation.

And now you know why, with anxiety, I also ask about digestion, bowel movements and previous courses of antibiotics.

Magnesium and B vitamins: what can they contribute to your inner brake?

Magnesium for stress, B vitamins for the nerves. You may know these phrases from advertising posters. What is behind them, and where are they exaggerated?

Magnesium is involved in many enzyme reactions and is considered a mineral that helps regulate the excitability of nerve cells. Vitamin B6 works as a tool when your body produces GABA. So both belong more to the building material of the brake than to the brake pedal itself.

With vitamin B6 in particular, caution is important. In 2023, the European Food Safety Authority (EFSA) set a tolerable upper intake level of 12 milligrams per day for adults, including during pregnancy and breastfeeding. The reason is nerve damage in the arms and legs, known as peripheral neuropathy. A team led by Hadtstein at Maastricht University describes how too much pyridoxine can specifically damage sensitive nerve cells. You can read more about this in Too much vitamin B6.

That is why I do not think much of taking high doses of magnesium and B vitamins on a hunch. It makes more sense to have your status measured and to top up specifically what is missing. You can read which form of magnesium may suit which purpose in Which magnesium is best?, and what the individual B vitamins do in B vitamins at a glance. I describe what a whole blood measurement can look like in Micronutrient analysis.

And now you know why, before any supplement, I would rather measure than guess.

Safety: what should you know before taking it?

Herbal sounds harmless. And passionflower is indeed considered well tolerated in studies. Even so, it is a medicinal product that targets your nervous system, and that deserves respect.

Also pay attention to the type of product. Registered herbal medicinal products are subject to stricter quality requirements than dietary supplements. You saw above, in the experiment from Portland, how different extracts can turn out. I describe in more detail why “herbal” does not automatically mean “proven” in Phytotherapy and evidence.

And now you know why, before any herbal calming remedy, I ask about your medication plan.

What can you do now, in practical terms?

You do not have to avoid passionflower. But you can put it in the right place.

Perhaps behind your restlessness there is a need for safety, for rest or for clarity. A first step could be to write this need down before you reach for the next pack.

You can read how your breath can engage the vagus nerve in Breathing techniques for the nervous system. Why exercise can be an underestimated lever for anxiety, in Exercise for depression and anxiety. And how passionflower and valerian perform for sleep, in Valerian and passionflower for sleep problems.

Frequently asked questions about passionflower for anxiety and restlessness

Further reading in the ViveCura guide

These articles are directly connected to this topic.