Chamomile: The Everyday Herb With Real Sleep and Anxiety Research Behind It

September 7, 2026

Chamomile is the supplement world's oldest cliché — the tea your grandmother made you before bed. That familiarity has a downside: it's easy to write chamomile off as folk medicine with no real research behind it. That's wrong. Chamomile has one of the more substantial human trial records of any calming herb, including a randomized trial that ran for nearly nine months. Here's what the research actually shows, what dose it was tested at, and how that compares to what's in Sleep Formula.

What chamomile is, and what's doing the work

"Chamomile" usually means German chamomile (Matricaria chamomilla, also called Matricaria recutita), a daisy-like flower that's been used in traditional medicine for centuries. The flower head contains dozens of compounds, but the one researchers keep coming back to is apigenin, a flavonoid concentrated in the plant's essential oil and extracts.

Apigenin is interesting because it isn't just "antioxidant-rich plant compound number 400." It has a proposed mechanism that's specific and testable: apigenin binds to benzodiazepine receptor sites on the GABA-A receptor complex — the same general receptor system that drugs like diazepam act on, though apigenin's binding affinity and effects are far weaker.² That's a plausible explanation for chamomile's calming, sleep-supportive reputation, and it's why apigenin content (not just "chamomile" as a vague label) is what standardized extracts are measured against.

26 weeks

The randomized, placebo-controlled phase of a University of Pennsylvania trial testing long-term chamomile extract for generalized anxiety disorder — one of the longest controlled trials run on any herbal anxiolytic.¹

The anxiety evidence: a real, long-running RCT

Most herbal supplement studies run for a few weeks. Chamomile has something rarer: a long-term randomized controlled trial in people formally diagnosed with generalized anxiety disorder (GAD), not just "stressed adults." Researchers gave 179 participants pharmaceutical-grade chamomile extract (1,500 mg/day, split into three 500 mg doses) for 12 weeks in an open-label phase. Just over half responded well enough to move into a 26-week double-blind, placebo-controlled continuation phase.¹

The relapse rate was numerically lower on chamomile than placebo (15.2% versus 25.5%), but that difference didn't reach statistical significance. What was significant: participants who stayed on chamomile had meaningfully lower GAD symptom scores throughout the follow-up period than those switched to placebo, alongside secondary improvements in body weight and blood pressure. The trial's own conclusion was measured — long-term chamomile was safe and reduced GAD symptoms, but wasn't proven to prevent relapse outright.¹

Chamomile isn't a substitute for anxiety treatment. It's a mild, well-studied option for people looking for daily support — and one of the few herbs with a trial long enough to actually test that claim.

The sleep evidence

Separate from the anxiety research, chamomile has been tested specifically for sleep quality. In a randomized trial of 60 elderly adults, 400 mg/day of chamomile extract for 28 days significantly improved scores on the Pittsburgh Sleep Quality Index compared to placebo — though it didn't meaningfully extend total sleep time over that short window.³ A separate trial in postpartum women with disrupted sleep found that drinking chamomile tea for two weeks improved sleep quality and reduced depressive symptom scores relative to usual care.⁴ Neither trial is enormous, but the direction is consistent across different populations and different chamomile formats (capsule extract vs. tea).

Studied doses vs. what's in Sleep Formula

One of the more confusing things about herbal supplements is that "chamomile" on a label can mean wildly different amounts of actual extract. Here's how the doses used in research compare:

Study	Population	Chamomile dose	Outcome measured
Mao et al., long-term GAD trial	Adults with generalized anxiety disorder	1,500 mg/day extract	GAD symptom severity, relapse
Adib-Hajbaghery & Mousavi, elderly sleep trial	Adults ~70 years old	400 mg/day extract	Pittsburgh Sleep Quality Index
Chang & Chen, postnatal sleep trial	Postpartum women	Chamomile tea, 2x/day	Sleep quality, depressive symptoms
Sleep Formula	General adult use	100 mg standardized extract	Formulated alongside other sleep-support ingredients

The 100 mg dose in Sleep Formula is lower than what was used in the standalone GAD and elderly-sleep trials — it's included as one contributor within a formula, not a stand-alone chamomile intervention at the studied ceiling dose. That's a distinction worth being upfront about: chamomile's own research supports doses considerably higher than 100 mg, and a formula's job is balancing multiple ingredients rather than maxing out any single one.

Safety: well-tolerated, with two real cautions

Chamomile has a long track record and is generally very well tolerated — most trials, including the 26-week one above, report mild or no side effects.⁵ Two things are worth knowing regardless:

Ragweed and related-plant allergies. Chamomile belongs to the Asteraceae (daisy) family, along with ragweed, chrysanthemums, marigolds, and daisies. People with allergies to those plants have a meaningfully higher risk of allergic reaction to chamomile, including rare but serious hypersensitivity reactions.⁵
Blood thinners. Chamomile has been reported to interact with warfarin, including a documented case report of elevated bleeding risk (INR) in a long-term chamomile tea user also on warfarin.⁶ Anyone on anticoagulant medication should talk to a doctor before adding chamomile in any form.

Key takeaway: Chamomile's apigenin content gives it a plausible, well-studied mechanism for calming effects, and it has real randomized trial data behind both anxiety and sleep quality use — including a rare 26-week controlled trial. Studied doses (400–1,500 mg/day) run well above the 100 mg included in Sleep Formula, where it's one part of a broader formula rather than a stand-alone dose. It's very well tolerated for most people, with clear cautions for ragweed-family allergies and blood thinner use.

Bottom line

Chamomile earns more credit than "just tea" gives it. The apigenin mechanism is specific and testable, the anxiety trial is one of the longest of its kind for any herbal option, and the sleep data — while smaller — points the same direction across different populations. If you're chamomile-curious, know that the doses shown to move the needle in trials are higher than what most single-serving teas or low-dose blends provide, and check with your doctor first if you're on a blood thinner or have ragweed-family allergies.

This article is for informational purposes only and has not been evaluated by the FDA. It is not intended to diagnose, treat, cure, or prevent any disease. Speak with a healthcare provider before starting any new supplement, especially if you take medication or have an existing health condition.

References

Mao JJ, Xie SX, Keefe JR, et al. Long-term chamomile (Matricaria chamomilla L.) treatment for generalized anxiety disorder: A randomized clinical trial. Phytomedicine. 2016;23(14):1735-1742. PubMed 27912875.
Avallone R, Zanoli P, Puia G, et al. Pharmacological profile of apigenin, a flavonoid isolated from Matricaria chamomilla. Biochem Pharmacol. 2000;59(11):1387-1394. PubMed 10751547.
Adib-Hajbaghery M, Mousavi SN. The effects of chamomile extract on sleep quality among elderly people: A clinical trial. Complement Ther Med. 2017;35:109-114. PubMed 29154054.
Chang SM, Chen CH. Effects of an intervention with drinking chamomile tea on sleep quality and depression in sleep disturbed postnatal women: a randomized controlled trial. J Adv Nurs. 2016;72(2):306-315. PubMed 26483209.
National Center for Complementary and Integrative Health (NCCIH), NIH. Chamomile: Usefulness and Safety. nccih.nih.gov/health/chamomile.
Segal R, Pilote L. Warfarin interaction with Matricaria chamomilla. CMAJ. 2006;174(9):1281-1282. PubMed 16636327.
Keefe JR, Guo W, Li QS, Amsterdam JD, Mao JJ. Short-term open-label chamomile (Matricaria chamomilla L.) therapy of moderate to severe generalized anxiety disorder. J Psychiatr Res. 2016;84:26-32. PubMed 27912871.