Chamomile promotes sleepiness primarily by reducing overall brain excitability rather than by “switching on” a sleep signal. The key compound responsible is a plant flavonoid called apigenin, which acts on several neurotransmitter systems in the brain to quiet neural activity. But the full picture is more interesting, and more nuanced, than most sources let on.
How Apigenin Calms Your Brain
For years, the popular explanation was simple: apigenin binds to the same brain receptors that anti-anxiety medications like benzodiazepines target, mimicking their sedative effect. That explanation turns out to be incomplete. Research from cortical neuron studies shows that apigenin’s affinity for the benzodiazepine binding site is actually quite low, and its sedative effect isn’t blocked by flumazenil, the drug used to reverse benzodiazepine effects. That means apigenin isn’t working the same way a sleeping pill does.
What apigenin does instead is reduce activity in a different channel: NMDA receptors, which are part of the brain’s excitatory signaling system. By dialing down this excitatory transmission, apigenin lowers the overall “volume” of neural activity. Think of it less like flipping a sleep switch and more like turning down a dimmer on brain stimulation. The result is a general calming effect that makes it easier to drift off, even though the mechanism is different from what pharmaceutical sedatives do.
Other Compounds That Contribute
Apigenin gets most of the attention, but chamomile flowers contain dozens of active compounds working together. The essential oils in chamomile, particularly bisabolol and chamazulene, have antispasmodic and anti-inflammatory properties. Roman chamomile contains up to 80% esters, which are naturally antispasmodic, meaning they help relax smooth muscle throughout the body. When your gut is calmer and your muscles are less tense, falling asleep becomes easier on a purely physical level.
Chamomile also appears to help lower cortisol, the hormone your body produces in response to stress. Cleveland Clinic lists chamomile alongside ashwagandha and lemon balm as herbs that may help reduce cortisol levels. This stress-lowering effect likely works alongside the brain-calming action of apigenin, creating a two-pronged approach: less mental stimulation and less physical tension.
What the Sleep Studies Found
Clinical trials have tested chamomile extract specifically for insomnia, and the results are modest but real. In a study of 195 elderly participants, taking 400 mg of chamomile extract daily for 28 days significantly improved sleep quality scores, and those improvements persisted even two weeks after participants stopped taking the supplement. A separate study in younger adults (ages 18 to 65) with chronic insomnia used a higher dose of 560 mg per day for 28 days and compared it to placebo.
These are extract capsules, not tea, so the doses are more concentrated than what you’d get from a cup of chamomile. A typical cup of chamomile tea contains less apigenin than a standardized extract capsule. That said, the ritual of drinking warm tea before bed carries its own sleep-promoting benefits: warmth, routine, and the act of slowing down all signal to your body that it’s time to wind down.
Timing and Preparation
The Sleep Foundation recommends drinking chamomile tea 45 to 60 minutes before bedtime for the best effect. This gives the active compounds time to absorb and start working before you’re trying to fall asleep. Steeping your tea for at least five minutes with a lid on the cup helps extract more of the active flavonoids from the dried flowers, since apigenin doesn’t dissolve in water as readily as some other compounds.
If you’re using loose chamomile flowers rather than tea bags, you’ll generally get a stronger brew. Two to three teaspoons of dried flowers per cup is a common starting point. The tea should have a golden yellow color and a distinctly floral, slightly apple-like aroma when properly steeped.
Who Should Be Cautious
Chamomile is safe for most people as a tea, but it does interact with certain medications. It can amplify the effects of blood thinners like warfarin and increase the sedative effects of other calming substances, including alcohol. It may also interfere with tamoxifen, hormone replacement therapy, and estrogen-containing birth control pills. If you take any of these, it’s worth a conversation with your doctor before making chamomile a nightly habit.
Chamomile belongs to the same plant family as ragweed, mugwort, and giant ragweed. Research has confirmed cross-reactivity between chamomile and these pollens, meaning if you have a ragweed allergy, chamomile could trigger a reaction ranging from mild irritation to, in rare cases, a serious allergic response. If ragweed season makes you miserable, start with a small amount of chamomile tea and see how you respond before committing to a full cup nightly.