Chamomile (Matricaria chamomilla, also known as German chamomile) is the gentle floral herb at the heart of Europe's most widely consumed herbal tea. In Ireland, a cup of chamomile before bed is a near-universal ritual for those seeking a calmer night. But does the science support the tradition?
Chamomile has been used medicinally in Europe for over 2,000 years, with references in ancient Egyptian, Greek, and Roman texts. In Irish and broader British folk medicine, chamomile tea was a standard remedy for nervousness, stomach complaints, and sleeplessness. The plant grows wild across Europe including in Ireland, and German chamomile is widely cultivated for commercial tea and supplement production.
Today, chamomile is available as loose leaf tea, teabags, tinctures, capsules, and standardised extracts. The concentration of active compounds varies considerably across these forms.
The most studied active compound in chamomile is apigenin, a flavonoid that binds to benzodiazepine receptors in the brain — the same receptor family targeted by diazepam (Valium) and other anxiolytic medications. Apigenin acts as a partial agonist at these receptors, producing a mild sedative and anxiolytic effect without the dependency or potency of pharmaceutical benzodiazepines.
Chamomile also contains alpha-bisabolol and chamazulene (responsible for the faint blue colour of chamomile essential oil), both of which have demonstrated anti-inflammatory and antispasmodic properties. These likely contribute to chamomile's traditional use for digestive complaints.
The most rigorous human trial of chamomile for anxiety is a series of studies conducted by Amsterdam et al. at the University of Pennsylvania. Their 2009 randomised double-blind placebo-controlled pilot trial (published in the Journal of Clinical Psychopharmacology) found that standardised chamomile extract (220–1,100 mg/day, standardised to 1.2% apigenin) produced statistically significant improvements in Hamilton Anxiety Scale (HAM-A) scores compared to placebo in patients with mild-to-moderate generalised anxiety disorder (GAD).
A 2016 follow-up trial by the same group (published in Phytomedicine) in 179 GAD patients demonstrated that longer-term chamomile use (up to 38 weeks) was associated with significantly reduced risk of anxiety relapse compared to placebo withdrawal. This longer-term study is particularly notable as it suggests more than just acute symptom relief.
These are encouraging findings, though it is important to note that the evidence base is still relatively small compared to conventional anxiolytic medications, and chamomile is not positioned as a substitute for clinical treatment of significant anxiety disorders.
The sleep evidence for chamomile is more limited. A 2017 randomised controlled trial by Hieu et al. in a sample of 60 elderly residents found that chamomile extract (200 mg twice daily) significantly improved sleep quality measures including sleep latency (time to fall asleep) and daytime functioning compared to placebo over four weeks.
A 2019 study examining chamomile tea in postnatal women found improvements in sleep quality and depression symptoms in the chamomile group, though this was a relatively small study.
The overall sleep evidence is moderate — promising but not yet definitive. Chamomile tea before bed is likely to have some mild sleep-promoting effect, particularly for people whose sleep is disrupted by mild anxiety or gastrointestinal discomfort.
| Claim | Evidence Level | Source |
|---|---|---|
| Chamomile extract reduces mild-to-moderate anxiety (GAD) | Moderate | Amsterdam et al. 2009, 2016 RCTs |
| Long-term chamomile reduces GAD relapse risk | Moderate | Amsterdam et al. 2016 (Phytomedicine) |
| Chamomile improves sleep quality in elderly | Moderate | Hieu et al. 2017 RCT |
| Chamomile tea before bed aids sleep onset | Limited | Mechanistic + observational; no dedicated RCT for tea specifically |
| Apigenin binds benzodiazepine receptors | Strong (pharmacological) | Multiple in vitro and animal studies |
Most clinical trials have used standardised extracts providing known quantities of apigenin, typically in capsule form. A standard cup of chamomile tea provides a much lower and more variable dose of apigenin than the 220–1,100 mg of extract used in trials. This doesn't mean tea is ineffective — many people find it genuinely calming — but it does mean that the trial evidence for standardised extract should not automatically be extrapolated to a nightly tea habit.
Allergy: Chamomile is a member of the Asteraceae (daisy/composite) family. People with known allergies to other members of this family — including ragweed, chrysanthemums, marigolds, and daisies — may have cross-reactive allergic reactions to chamomile. Anaphylaxis has been reported, though it is rare. If you have composite plant allergies, start with a small amount and be observant.
Pregnancy: Chamomile tea in moderate amounts (one to two cups daily) is generally considered to be of low risk during pregnancy, though the evidence base for safety in pregnancy is not comprehensive. High-dose chamomile preparations and chamomile supplements should be avoided in pregnancy, as chamomile has historically been associated with uterine stimulant activity and there are theoretical concerns about early labour. Discuss with your GP or midwife before using chamomile during pregnancy.
Anticoagulants (blood thinners): Chamomile contains coumarin compounds which may have mild anticoagulant effects. If you take warfarin, aspirin, or other blood-thinning medications, high-dose chamomile preparations could theoretically increase bleeding risk. Discuss with your pharmacist or GP.
Sedative medications: Chamomile may enhance the sedative effects of alcohol, benzodiazepines, and other sedating medications. Avoid combining high-dose chamomile preparations with sedatives.
When to see your GP: Significant anxiety or insomnia that impacts daily functioning warrants professional assessment. Chamomile may be a gentle adjunct but should not replace evidence-based treatments for clinical anxiety disorders or chronic insomnia.
For maximum flavour and potential potency, use two to three teaspoons of dried chamomile flowers (or one to two good-quality teabags) per mug. Pour freshly boiled water over the flowers, cover the mug, and steep for five to ten minutes covered. The cover prevents volatile aromatic compounds from escaping with the steam. Strain, allow to cool slightly, and drink 30–60 minutes before bed.
Chamomile stands out among herbal teas as having actual clinical trial evidence behind it, particularly for mild anxiety. The sleep evidence is more limited but plausible given the established pharmacological mechanism. For mild, situational anxiety and sleep difficulty, chamomile — especially in standardised extract form — is a reasonable, well-tolerated, and evidence-grounded choice. It is gentle enough that the phrase "a cup of chamomile" has become cultural shorthand for winding down, and the science mostly supports that intuition.
For quality chamomile teas and herbal sleep supplements, shop at our partner
Shop at The Honey Pot →