Chamomile for Anxiety: The Calming Herb That Passed the Scientific Test

In almost every home, in some kitchen cabinet, there is a bag of chamomile tea. The small plant with white flowers and a yellow center has been considered since ancient Egypt as a grandmother's remedy for stress, upset stomach, and insomnia. For thousands of years, the belief that a cup of chamomile tea before sleep calms the mind relied solely on tradition, not science. And that is precisely why most folk remedies remain folklore.

But chamomile has received something that very few calming plants have been granted: a series of randomized, double-blind, placebo-controlled clinical studies, on people with a real diagnosis of generalized anxiety disorder. This elevates it a step above most herbal teas that promise calm. In this guide, we will examine what really happens when you replace the tea bag with a standardized extract, and why the answer still requires caution.

What is Chamomile?

Chamomile is a general name for several plants from the Asteraceae family. Here is what you need to know:

• German Chamomile (Matricaria recutita, also known as Matricaria chamomilla) is the variety studied in anxiety research. Do not confuse it with Roman chamomile, another variety with a slightly different profile.
• The main active ingredient in the context of anxiety is a flavonoid called apigenin. A standardized pharmaceutical extract typically contains about 1.2% apigenin.
• The studied form is not regular tea but a concentrated extract in capsules. A cup of tea contains a much smaller amount of active ingredients than the dosage given in studies.
• Mechanism of action on the nervous system, not correction of a nutritional deficiency. In this sense, chamomile is more similar to a calming herb than to an essential vitamin.

The Connection to Anxiety: A Surprising Mechanism

The reason chamomile is not just a warm, pleasant drink is related to one molecule: apigenin. Laboratory studies have shown that apigenin has affinity for the GABA-A receptor in the brain, the same receptor on which sedative drugs from the benzodiazepine family, such as Valium and Xanax, act.

GABA is the brain's main inhibitory neurotransmitter. When it binds to the GABA-A receptor, it 'turns down the volume' of excessive neural activity, and this produces a feeling of calm. Chamomile mimics, very gently, part of this effect, but with significantly lower potency than prescription drugs, and without the addiction profile characteristic of benzodiazepines.

Additionally, there is early evidence that apigenin also affects serotonin, dopamine, and norepinephrine, the same neurotransmitters that influence mood. This explains why in one study, an antidepressant effect was also observed, not just an anti-anxiety effect. The good news: the effect is gentle. The less good news: the benefit is correspondingly moderate.

Current Evidence

Study 1: Amsterdam 2009, The Landmark Study

The study that transformed chamomile from a grandmother's remedy to a scientific candidate was published in the Journal of Clinical Psychopharmacology in 2009. It was a randomized, double-blind, placebo-controlled study: 57 patients with mild to moderate generalized anxiety disorder received standardized chamomile extract or placebo for 8 weeks.

The result: The chamomile group showed a statistically significant reduction in the Hamilton Anxiety Rating Scale (HAM-A) score compared to placebo (p=0.047). All sub-measures moved in the same positive direction. This was the first controlled study to show that chamomile extract can reduce real anxiety symptoms, not just a subjective feeling of calm.

Study 2: Mao 2016, The Long-Term Test

The more important question is not whether chamomile helps in the short term, but whether it holds up over time and prevents relapse. This was examined in a study by Mao and colleagues, published in Phytomedicine in 2016. 179 participants with moderate to severe generalized anxiety received 1500 mg of chamomile extract per day (500 mg three times daily) for 12 open-label weeks, and those who responded (about 52%) were randomly assigned to chamomile or placebo for an additional 26 weeks.

The results are complex and honest: The relapse rate in the chamomile group was 15.2% vs. 25.5% in the placebo group, but the difference did not reach full statistical significance (p=0.16). However, the average time to relapse was significantly longer in the chamomile group: 11.4 weeks vs. 6.3 weeks in the placebo group, and the increase in anxiety symptoms (GAD-7 score) was significantly smaller (p=0.0032).

Study 3: Safety and Side Effects

An important point from the 2016 study: The safety profile was almost identical to placebo. Possible side effects were observed in 17.4% of the chamomile group vs. 19.1% of the placebo group, and all were rated as mild. Interestingly, the chamomile group also had significantly lower body weight and mean arterial blood pressure. This is one of the reasons chamomile is rated yellow and not red: even if the effect is moderate, it is gentle and relatively safe.

What About Insomnia and Depression?

Anxiety often does not come alone. Another study examined standardized chamomile extract in people with chronic insomnia, and showed a trend towards improved sleep quality, although the evidence there is weaker than for anxiety. Separately, an analysis of data from the Amsterdam study indicated a possible antidepressant effect in those who suffered from both anxiety and depression.

It is important to qualify: There is no evidence here that chamomile treats clinical depression or severe insomnia. Those suffering from these conditions need diagnosis and professional treatment. At best, chamomile can provide gentle support in mild to moderate cases, and not replace real treatment.

Should You Start Taking Chamomile?

This is where the yellow rating comes into play. Chamomile is not green (strong and consistent evidence) and not red (hype without basis), it is right in the middle. Here is the critical side:

• The effect is moderate: Even the positive 2009 study showed a difference that barely crossed the significance threshold (p=0.047). This is not a powerful treatment, but a gentle push.
• Few studies, and some are small: Most of the evidence comes from one research group (Amsterdam and colleagues). Large, independent studies confirming the results are lacking.
• Allergy: Those sensitive to plants in the Asteraceae family (ragweed, chrysanthemums, marigolds) may develop an allergic reaction, sometimes severe. This is the most important warning.
• Anticoagulants: Chamomile contains coumarins and may increase the effect of blood-thinning medications like warfarin. Caution is required.
• Pregnancy: In high amounts, chamomile is not recommended during pregnancy. An occasional cup of tea is one thing, a concentrated extract is another.

If your anxiety is mild and situational, and your doctor approves, chamomile is a reasonable and relatively safe attempt. If anxiety disrupts your daily functioning, you need real treatment, not tea.

What to Take Away from the Research?

1. Dosage: 200-1100 mg standardized extract per day. The studies used a range of about 500 to 1500 mg per day, usually divided into several doses. Start at the low end.
2. Choose a standardized extract for apigenin, not just flower powder. A regular cup of tea contains a much lower amount than the therapeutic dose. Purchase chamomile extract on iHerb.
3. Test for allergies first: If you are sensitive to ragweed or plants in the Asteraceae family, do not touch chamomile without asking a doctor.
4. Give it time: In studies, the effect was measured over weeks, not days. Do not expect a dramatic change within a day or two.
5. Do not stop existing treatment: If you are taking anxiety medications, anticoagulants, or are pregnant, consult a doctor before adding chamomile.

Not sure if chamomile is right for your goals? You can run our personal supplement selector and get a recommendation tailored by age, gender, and goals.

The Broader Perspective

Chamomile is a beautiful example of what a 'yellow' supplement really looks like. It is not magic, but it is also not a scam: it has two placebo-controlled studies with positive results in a consistent direction, a plausible biological mechanism via the GABA receptor, and an excellent safety profile. On the other hand, the effect is moderate, the evidence is limited, and most of it comes from one research group.

The big lesson is that a calming herb, even the best of them, is not a substitute for treating real anxiety. Adequate sleep, physical activity, slow breathing, and cognitive-behavioral therapy when needed will affect your anxiety much more than any capsule. Chamomile can be a gentle aid in moments of mild stress, a soft bridge to calm. But if anxiety controls your life, no tea will replace the help you deserve.

References:
Amsterdam JD, et al. A randomized, double-blind, placebo-controlled trial of oral Matricaria recutita (chamomile) extract therapy for generalized anxiety disorder. J Clin Psychopharmacol. 2009;29(4):378-382.
Mao JJ, et al. Long-term chamomile (Matricaria chamomilla L.) treatment for generalized anxiety disorder: A randomized clinical trial. Phytomedicine. 2016;23(14):1735-1742.
Amsterdam JD, et al. Chamomile (Matricaria recutita) may provide antidepressant activity in anxious, depressed humans: an exploratory study. Altern Ther Health Med. 2012;18(5):44-49.