What are the side effects of Chamomile?

Generally mild and placebo-comparable Occasional GI upset or drowsiness Rare hypersensitivity, including anaphylaxis in ragweed-allergic people

Who should avoid Chamomile?

Allergy to ragweed, daisy, marigold, or other Asteraceae/Compositae plants Pregnancy without clinician guidance (traditional emmenagogue caution)

Botanical

Chamomile

A gentle, well-tolerated evening botanical studied for mild anxiety and sleep quality, plausibly via the flavone apigenin acting on GABA pathways. The effect is genuine but small, and the sleep data are early: a calm-slot ingredient, not a sedative.

Grade CUpdated July 12, 2026Written and fact-checked in-house against The Evidence Standard. Not a clinical review.

Photo by Enrique on Pexels

Please note

Educational content, not medical advice. Doses below are ranges used in research, not recommendations. Talk to a qualified clinician before starting any supplement, especially if you take medication, are pregnant, or manage a health condition.

Evidence grade: Evidence: Grade C
Studied dose range: 220–1500 mg/day of a standardized extract (often 500 mg of a 1.2% apigenin extract, 1–3× daily); tea is the traditional, lower-and-more-variable-dose form.
Time to effect: The anxiety signal builds over roughly 2–4 weeks; sleep effects are modest and gradual.
Best form: Standardized extract (≈1.2% apigenin) matches the trial material; tea is traditional but under-dosed by comparison.

The short answer

Chamomile (Botanical) is studied for occasional nervous tension and evening wind-down and subjective sleep quality. In our conservative reading of the published human research, the evidence is Grade C (limited). 220–1500 mg/day of a standardized extract (often 500 mg of a 1.2% apigenin extract, 1–3× daily); tea is the traditional, lower-and-more-variable-dose form. The anxiety signal builds over roughly 2–4 weeks; sleep effects are modest and gradual. A studied dose is what trials used, not a recommended dose.

Full profile

Also known as	Matricaria recutita, Matricaria chamomilla, Apigenin
Best for	Occasional nervous tension and evening wind-down · Subjective sleep quality · A low-risk calm-slot botanical
Evidence grade	Grade C · Limited: early or small human trials
Studied dose range	220–1500 mg/day of a standardized extract (often 500 mg of a 1.2% apigenin extract, 1–3× daily); tea is the traditional, lower-and-more-variable-dose form.
Time to effect	The anxiety signal builds over roughly 2–4 weeks; sleep effects are modest and gradual.
Best form	Standardized extract (≈1.2% apigenin) matches the trial material; tea is traditional but under-dosed by comparison.
Food sources	Chamomile tea (traditional, lower dose than studied extracts)

Evidence, honestly graded

Limited. Chamomile has the cleanest evidence of the common calm botanicals because its core trials are NIH-funded rather than sponsor-run: an 8-week RCT improved generalized-anxiety scores versus placebo (Amsterdam 2009), and a 2024 meta-analysis found a small improvement in sleep quality (Kazemi 2024), but the sleep trials are methodologically weak, and a standardized chronic-insomnia pilot missed its primary sleep-diary endpoints (Zick 2011). A longer-term anxiety trial (Mao 2016) missed its primary relapse-prevention endpoint while showing positive secondary outcomes. Real but small and early: a C.

See the full grading rubric (study type, replication, population match, and dose adequacy) in The Evidence Standard.

877 natural health products with an active licence in Health Canada's LNHPD list Chamomile as a medicinal ingredient.

That makes Chamomile a recognized, licensable medicinal ingredient in Canada, regulated by Health Canada's Natural and Non-prescription Health Products Directorate, which issues each licensed natural health product a Natural Product Number (NPN). Search the LNHPD to verify.

Source: Health Canada Licensed Natural Health Products Database, snapshot 2026-10-18. A count of products with an active licence, not an endorsement of any health claim. This describes the ingredient's regulatory standing in Canada, not Signal State Core, which is a pre-launch concept and is not a licensed natural health product.

Side effects

Generally mild and placebo-comparable
Occasional GI upset or drowsiness
Rare hypersensitivity, including anaphylaxis in ragweed-allergic people

Who should avoid it or check first

Allergy to ragweed, daisy, marigold, or other Asteraceae/Compositae plants
Pregnancy without clinician guidance (traditional emmenagogue caution)

Interactions

May add to the effect of sedatives and other CNS depressants
Coumarin content; caution with anticoagulants/antiplatelets (isolated INR case reports)

Stacks well with

Use caution stacking with

Stacking multiple sedating botanicals without guidance

What to look for on a label

Carry an Asteraceae-allergy caution (ragweed cross-reactivity).
Health Canada's German Chamomile monograph permits sleep/calmative claims on a TRADITIONAL herbal basis: history of use, not a finding of clinical efficacy. Keep "traditionally used" wording distinct from a proof-of-effect claim.

References

Amsterdam JD, Li Y, Soeller I, Rockwell K, Mao JJ, Shults J (2009). Journal of Clinical Psychopharmacology, 29(4):378–382RCT, n=57, 8 weeksStudied dose: 220–1100 mg/day standardized extractGreater reduction in anxiety scores than placebo.
Kazemi A, Shojaei-Zarghani S, Eskandarzadeh P, Hashempur MH (2024). Complementary Therapies in Medicine, 84:103071Systematic review and meta-analysis, 10 trialsSmall improvement in sleep quality; low methodological quality.
Zick et al. (2011): standardized chamomile for chronic insomnia (null primary). 270 mg twice daily; no significant benefit on the primary sleep-diary endpoints, the honest counterweight to the softer sleep-quality data. PMID 21939549. Educational, not a product claim.

Grades and studied doses are our conservative reading of the human research, shown for education. They are not product claims, and a studied dose is not a recommended dose.

Revision history

Every change to this ingredient's evidence status, dated and explained. The full cross-library log lives at Evidence Updates.

2026-07-12New profile
New profile at Grade C for sleep/relaxation, on limited human data.

See how Chamomile compares on grade, dose, and goal in the Evidence Explorer.

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