Chamomile — Research Profile

For mild relaxation and sleep support, chamomile tea can be helpful — the bedtime ritual itself contributes to sleep hygiene. However, a typical cup of chamomile tea contains only about 3-10mg of apigenin, while clinical studies used standardized extracts providing 2.6-6mg of apigenin in a more concentrated form. For clinically meaningful anxiety reduction, a standardized extract (220-500mg, 1.2% apigenin) is more reliable than tea alone. ^[1]

Use caution — chamomile belongs to the Asteraceae (daisy) family, which also includes ragweed. Cross-reactivity is possible, though not universal. If you have severe ragweed allergies, start with a very small dose and monitor for allergic reactions. Some people with ragweed allergies tolerate chamomile well, while others experience sneezing, rash, or in rare cases anaphylaxis.

Chamomile is milder than prescription anxiolytics like benzodiazepines or SSRIs. The Amsterdam 2009 RCT showed significant benefits for mild-to-moderate GAD, but chamomile has not been tested head-to-head against standard medications. Its advantages include safety, no dependence risk, and fewer side effects. It is best suited for mild anxiety or as an adjunct to conventional treatment, not as a replacement for medication in moderate-to-severe anxiety disorders.

Standardized oral capsule extracts of German chamomile have the strongest controlled evidence, used at 200-1500 mg/day in the anxiety and sleep trials. Chamomile tea is the traditional form and is used in sleep studies, but it delivers a less consistent dose than a labeled extract. For mouth-sore (mucositis) inflammation, chamomile has been applied topically as a mouth rinse rather than swallowed, so the best form depends on the target use.

The best-supported benefit is modest relief of generalized anxiety disorder: pooled trials show significant HAM-A reductions at 2-4 weeks, and an 8-week RCT found greater improvement than placebo (P=0.047). A meta-analysis of 10 studies (772 people) found chamomile improved overall sleep quality (PSQI weighted mean difference -1.88, 95% CI -3.46 to -0.31), though sleep duration and efficiency did not improve. Evidence for short-term state anxiety was not significant (SMD -0.15, P=0.42), and anti-inflammatory benefit is limited mainly to reducing oral mucositis pain and severity.

No official daily intake is established because chamomile is a botanical, not a nutrient, and trials used a range depending on the goal. Generalized-anxiety studies used 220-1500 mg/day of standardized extract, including a long-term trial at 1500 mg/day split into 500 mg three times daily, while an elderly sleep trial used 400 mg/day (200 mg twice daily). Tea is dosed by cups rather than milligrams, so a standardized capsule is the way to match these trial amounts.

Timing has not been directly compared in trials. Sleep studies dosed chamomile in the evening, and the elderly nursing-home trial split 200 mg into a twice-daily schedule, while anxiety trials divided the daily dose across the day (for example 500 mg three times daily). Because chamomile can cause drowsiness, taking a dose in the evening is reasonable if sleep is the goal, whereas divided daytime dosing was used for anxiety.

A systematic review of adverse events found the most common effects were gastrointestinal upset and drowsiness, both self-limiting and non-serious, with no allergic events in the controlled trials. The serious but rare risk is allergy: among eleven case reports, six involved allergic reactions, including anaphylaxis in three patients, and risk is higher in people allergic to ragweed, chrysanthemums, marigolds, or daisies. Data on safety during pregnancy and breastfeeding remain insufficient.

According to NCCIH, chamomile has reported interactions with warfarin and other blood thinners, may add to the effect of sedative medications, and its estrogen-like activity might reduce the effectiveness of birth control pills. It may also interact with drugs processed by the liver's metabolizing enzymes. Tell your prescriber before combining chamomile with anticoagulants, sedatives, or hormonal contraceptives.

Adults with mild-to-moderate generalized anxiety or poor sleep quality have the most supporting trial evidence, with GAD symptom reductions at 2-4 weeks and improved PSQI sleep scores. It is a poor choice for anyone allergic to ragweed, chrysanthemums, marigolds, or daisies given the risk of allergic reactions including anaphylaxis. People taking warfarin, sedatives, or hormonal contraceptives, and those who are pregnant or breastfeeding, should check with a clinician first because interaction and safety data are limited.

In a meta-analysis of randomized trials, oral chamomile produced measurable reductions in generalized-anxiety (HAM-A) scores as early as 2 weeks (mean difference -1.43, P=0.007), improving further by 4 weeks (-1.79, P=0.0097). Sleep-quality trials typically ran 2-4 weeks before showing benefit, and the elderly-nursing-home trial measured improvement after 28 days of 200 mg twice daily. Plan on a few weeks of consistent use rather than a single dose for anxiety or sleep effects.

The longest controlled data come from a generalized-anxiety trial that gave 1500 mg/day (500 mg three times daily) for up to 38 weeks (12 weeks open-label plus 26 weeks randomized), with adverse-event rates as low as placebo and small reductions in body weight and mean arterial pressure. Safety beyond roughly 9 months has not been established in trials, and a systematic review notes insufficient data during pregnancy and lactation. The main long-term concern is not cumulative toxicity but allergic sensitization, especially in people allergic to ragweed or related daisy-family plants.

Chamomile is not a nutrient and has no established tolerable upper intake level, and controlled trials using up to 1500 mg/day of standardized extract reported only mild, self-limiting effects. The dominant risk is not dose-dependent toxicity but allergic reaction: case reports document anaphylaxis in three patients, though no allergic events occurred in the clinical trials themselves. Higher intakes also increase drowsiness, so avoid combining large amounts with sedatives or driving.

The most relevant caution is additive sedation: chamomile can increase drowsiness, so pairing it with other sleep-promoting supplements (for example valerian or melatonin) may compound that effect. Because NCCIH lists reported interactions with warfarin and other blood thinners, be cautious stacking it with supplements that also affect clotting, such as high-dose fish oil or vitamin E. No trial has tested chamomile in specific supplement combinations, so these are precautionary rather than demonstrated interactions.

Choose German chamomile (Matricaria chamomilla, also listed as Matricaria recutita), which is the species used in the anxiety and sleep trials, and look for a capsule standardized to its apigenin content since apigenin is the flavonoid tied to the sedative and anxiolytic effects. Studied doses ranged from 200 mg capsules to 500 mg capsules of standardized extract, so a labeled extract weight lets you match trial amounts. Because chamomile cross-reacts with ragweed and daisy-family allergies, confirm the species and, if you react to those plants, treat any product with caution.