Relax or Refocus? The Science Behind Chamomile and Green Tea

Introduction

In today’s fast-paced and demanding world, many of us are constantly seeking a quick way to recharge – something that can both relax the mind and boost energy for the day ahead. This is where teas like chamomile and green tea come in. But why do people reach for tea when they want calm? While both chamomile and green tea can promote relaxation, the type of calm they provide is quite different. That’s where the key compounds – apigenin in chamomile and L-theanine in green tea – play a central role. In this article, we’ll explore how these compounds work, where they come from, and ultimately help you decide which tea to choose depending on the effect you’re looking for.

What Each Compound Is

Apigenin

Apigenin (4′,5,7-trihydroxyflavone) is a commonly occurring flavonoid found across many plant species and is classified within the flavone group. Members of the Asteraceae family serve as some of its most notable natural sources. [1] The term “apigenin” originates from the Apium genus in the Apiaceae family, which includes familiar plants such as celery, carrots, and parsley (also called the Umbelliferae). [2] Apigenin is recognized as a non-mutagenic bioflavonoid and has displayed anti-proliferative, anti-inflammatory, and antioxidant (free radical-scavenging) actions in a variety of in vitro experiments. It is generally viewed as both non-mutagenic and non-toxic. [3] Research also links apigenin to biological mechanisms involved in relaxation and sleep. For example, flies with induced dementia exhibit reduced oxidative stress when given apigenin, and studies in rodents show decreases in stress hormones alongside increases in serotonin – one of the neurotransmitters associated with sleep regulation in humans. [4] In practical terms, apigenin may explain why chamomile tea often feels like a gentle “wind-down” aid – similar to turning down a dimmer switch as bedtime approaches.

L-Theanine

L-theanine (γ-glutamylethylamide) is an uncommon non-protein amino acid naturally present in abundance in green tea (Camellia sinensis), a beverage widely valued for its potential health benefits, making up more than half of the total free amino acid content. [5, 6] Rodent studies have highlighted L-theanine’s possible neuroprotective and cognitive-enhancing properties. [5] L-Theanine is beneficial for improving focus, enhancing relaxation, preventing cardiovascular conditions, and most importantly, overpowering the effect of caffeine. [6] It is worth noting that the well-known effect described as “calm alertness” as evidence indicates that components of green tea – particularly L-theanine and catechins – may support clearer thinking while simultaneously fostering relaxation. [7] It plays a major role in shaping green tea’s taste and flavor profile and is therefore a key marker of tea quality. [6] Many tea drinkers describe L-theanine as contributing to a “smooth focus,” as if it softens the intensity of alertness without causing any sense of sleepiness.

Where They Come From

Apigenin in Chamomile

Apigenin is found in especially high amounts in chamomile tea, which is prepared from the dried blossoms of Matricaria chamomilla. This annual herb originated in Western Asia and Europe but has since spread and now grows naturally in regions such as Australia, Britain, and the United States. [2] Besides chamomile, apigenin is also present in various plants commonly used in traditional or herbal remedies, including propolis, Combretum erythrophyllum, Gentiana veitchiorum, Marrubium globosum, and Portulaca oleracea L. [8]

Chamomile tea is among the richest natural contributors of apigenin, typically offering about 0.8% to 1.2% apigenin by volume. Although apigenin was first synthesized in 1939, it didn’t draw substantial scientific interest until the 1960s, when researchers observed its ability to inhibit histamine release and promote bronchodilation. [9] Chamomile infusions also contain essential oils responsible for their characteristic scent, taste, and colour. [2]

Still, apigenin isn’t exclusive to herbal teas. It also appears in a range of everyday foods – citrus fruits such as grapefruit and oranges, onions, parsley, wheat sprouts, teas, and numerous herbs and spices – where it generally occurs in a glycosylated form. [7]

L-Theanine in Green and Black Tea

L-theanine – formally l-(γ-l-glutamylethylamide) – is a non-nutritive amino acid primarily associated with tea. Its concentration in tea leaves can vary widely depending on the cultivar, harvest timing, seasonal factors, and even brewing methods. [7]

Green tea, derived from Camellia sinensis, is the most recognized source of L-theanine, valued both for its flavor and its proposed health benefits. [11] Theanine occurs across multiple tea varieties – white, green, oolong, and black – each produced through distinct oxidation processes. These teas typically contain about 0.9% to 3.1% theanine by dry weight, amounting to roughly 5.8 to 32 mg in a standard 200 ml serving brewed from 3 g of leaves. One analysis of 37 commercial teas reported an average content of 6.56 mg/g, but because so many variables affect its levels, the theanine content of brewed tea is difficult to standardize. [7]

Seasonal influences also play a notable role: tea harvested in early summer tends to hold higher theanine levels than tea picked later in the season. This helps account for differences among teas from the same region. For instance, Ceylon black tea classified as Pekoe contains more theanine than the Broken grade, despite both being sourced from the same area of Sri Lanka. [12]

Sources aside, the real question is: what happens after we drink them? That brings us to how each compound works inside the body.

How They Work in the Body

Apigenin: turning down brain excitability

Apigenin’s calming effects come mainly from its interaction with neurotransmitters involved in relaxation. Research in animals shows that apigenin can enhance the effects of GABA – the brain’s primary “slow-down” neurotransmitter – by increasing chloride ion flow through GABAA receptors, leading to easier onset of sleep and deeper relaxation. [13]

Beyond this, apigenin also affects the excitatory side of the brain’s signaling system. Studies using cultured neurons demonstrate that it modulates both GABA and glutamate pathways by reducing NMDA-receptor activity [14]. This dual action means apigenin is not only helping promote calm but also gently lowering excessive excitatory signaling.

Another study using hippocampal nerve terminals found that apigenin reduces glutamate release by blocking calcium channels involved in neurotransmitter release. [14] Since glutamate is linked to stress, overstimulation, and neural wear-and-tear, this offers an explanation for apigenin’s neuroprotective effects.

A broader review also highlights apigenin’s ability to lower oxidative stress, decrease stress hormones, and increase serotonin – all of which support better sleep and emotional balance [10].

Put together, these mechanisms explain why chamomile tea feels like a “wind-down switch”: apigenin reduces neural overactivity while slightly boosting the brain’s natural calming systems.

L-theanine: promoting calm alertness

L-theanine works almost in the opposite direction: instead of promoting sedation, it encourages a mental state often described as relaxed concentration.

Human EEG research shows that L-theanine increases alpha brain wave activity – the frequency range associated with wakeful relaxation, meditative calm, and improved focus [15]. This explains why green tea tends to feel smoother and less jittery than coffee, even though both contain caffeine.

Another set of studies suggests L-theanine influences several neurotransmitters at once. It appears to increase GABA (calm), serotonin (mood), and dopamine (motivation and attention), while also slightly dampening the stress response system, including cortisol levels in stressful scenarios. [16]. This makes theanine unique: instead of making the brain sleepy, it stabilizes attention and promotes mental clarity.

Because it crosses the blood-brain barrier, L-theanine can exert these effects relatively quickly, often within 30-45 minutes of ingestion.

Association with Health and Wellness

Chamomile tea has been found to improve certain aspects of sleep, particularly by reducing nighttime awakenings and helping people stay asleep. However, it may have little impact on total sleep duration, sleep efficiency, or daytime functioning. [17] Drinking chamomile tea daily for two weeks has also been shown to improve sleep quality and mental well-being in postpartum women who experience poor sleep. [18] Individuals who are allergic to plants in the Asteraceae family or who take medications processed by cytochrome P450 enzymes should use caution when consuming chamomile tea. [19]

Green tea is linked to multiple health benefits but should be consumed in moderation. Experts recommend that adults limit epigallocatechin gallate (EGCG) intake to no more than 338 mg per day, roughly equivalent to 5-6 cups of green tea, to prevent potential liver toxicity. [20, 21] Studies suggest that combining L-theanine with caffeine can improve focus, alertness, and overall efficiency more than either compound alone. Consequently, matcha – a powdered form of green tea that has grown in popularity – may offer neuroprotective benefits. However, the specific effects and mechanisms of matcha are not yet fully understood, and more research is needed on its interactions with gut microflora and its potential influence on infectious diseases. [22, 23]

Conclusion

Both chamomile and green tea offer calming benefits, but in distinct ways. Chamomile, with its apigenin content, gently eases the body into relaxation and supports sleep, while green tea, thanks to L-theanine, promotes a calm yet alert state of focus. Understanding these differences can help you choose the right tea for your needs – whether you’re winding down at night or looking for a focused boost during the day. By appreciating the unique effects of these compounds, enjoying tea becomes more than just a ritual - it’s a simple, natural way to support your wellness and mental clarity.

References

1. Salehi B, Venditti A, Sharifi-Rad M, Kręgiel D, Sharifi-Rad J, Durazzo A, et al. The Therapeutic Potential of Apigenin. International Journal of Molecular Sciences [Internet]. 2019 Mar 15;20(6):1305. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6472148/

2. Shankar E, Goel A, Gupta K, Gupta S. Plant Flavone Apigenin: an Emerging Anticancer Agent. Current Pharmacology Reports. 2017 Oct 14;3(6):423–46.

3. Sen P, Sahu PK, Haldar R, Sahu KK, Prasad P, Roy A. Apigenin Naturally Occurring Flavonoids:Occurrence and Bioactivity. UK Journal of Pharmaceutical Biosciences. 2016 Dec 1;4(6):56.

4. Is Apigenin Safe? And How it Improves Sleep and Aging [Internet]. Nad.com. 2024. Available from: https://www.nad.com/news/apigenin-sleep-and-aging-promises-and-safety

5. Hidese S, Ogawa S, Ota M, Ishida I, Yasukawa Z, Ozeki M, et al. Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial. Nutrients [Internet]. 2019 Oct 3;11(10):2362. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6836118/

6. Mu W, Zhang T, Jiang B. An overview of biological production of L-theanine. Biotechnology Advances [Internet]. 2015 May 1;33(3):335–42. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0734975015000695

7. Dashwood R, Visioli F. l-theanine: From tea leaf to trending supplement – does the science match the hype for brain health and relaxation? Nutrition Research [Internet]. 2025 Jan 2;134:39–48. Available from: https://www.sciencedirect.com/science/article/pii/S0271531724001684#bbib0048

8. Mushtaq Z, Nabeelah Bibi Sadeer, Hussain M, Mahwish, Alsagaby SA, Imran M, et al. Therapeutical properties of apigenin: a review on the experimental evidence and basic mechanisms. International Journal of Food Properties. 2023 Jul 20;26(1):1914–39.

9. Singh A, Singh J, Gulistan Parween, Rakesh Khator, Monga V. A comprehensive review of apigenin a dietary flavonoid: biological sources, nutraceutical prospects, chemistry and pharmacological insights and health benefits. Critical Reviews in Food Science and Nutrition. 2024 Aug 17;1–37.

10. Kramer DJ, Johnson AA. Apigenin: a natural molecule at the intersection of sleep and aging. Frontiers in nutrition. 2024 Feb 27;11.

11. Williams J, McKune AJ, Georgousopoulou EN, Kellett J, D’Cunha NM, Sergi D, et al. The Effect of L-Theanine Incorporated in a Functional Food Product (Mango Sorbet) on Physiological Responses in Healthy Males: A Pilot Randomised Controlled Trial. Foods [Internet]. 2020 Mar 1;9(3):371. Available from: https://www.mdpi.com/2304-8158/9/3/371/htm

12. Vuong QV, Bowyer MC, Roach PD. L-Theanine: properties, synthesis and isolation from tea. Journal of the Science of Food and Agriculture. 2011 Mar 29;91(11):1931–9.

13. Kim JW, Kim CS, Hu Z, Han JY, Kim SK, Yoo SK, et al. Enhancement of pentobarbital-induced sleep by apigenin through chloride ion channel activation. Archives of Pharmacal Research. 2012 Feb;35(2):367–73.

14. Losi G, Puia G, Garzon G, de Vuono MC, Baraldi M. Apigenin modulates GABAergic and glutamatergic transmission in cultured cortical neurons. European Journal of Pharmacology [Internet]. 2004 Oct 11;502(1-2):41–6. Available from: https://pubmed.ncbi.nlm.nih.gov/15464088/

15. Gomez-Ramirez M, Kelly SP, Montesi JL, Foxe JJ. The effects of L-theanine on alpha-band oscillatory brain activity during a visuo-spatial attention task. Brain Topography [Internet]. 2009 Jun 1;22(1):44–51. Available from: https://www.ncbi.nlm.nih.gov/pubmed/18841456

16. Evans M, McDonald AC, Xiong L, Crowley DC, Guthrie N. A Randomized, Triple-Blind, Placebo-Controlled, Crossover Study to Investigate the Efficacy of a Single Dose of AlphaWave®l-Theanine on Stress in a Healthy Adult Population. Neurology and Therapy [Internet]. 2021 Sep 25;1–18. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8475422/

17. Kazemi A, Shojaei-Zarghani S, Parham Eskandarzadeh, Mohammad Hashem Hashempur. Effects of chamomile (Matricaria chamomilla L.) on sleep: A systematic review and meta-analysis of clinical trials. Complementary Therapies in Medicine. 2024 Aug 1;84:103071–1.

18. 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. Journal of Advanced Nursing [Internet]. 2015 Oct 20;72(2):306–15. Available from: https://pubmed.ncbi.nlm.nih.gov/26483209/

19. Ji Won Yeom, Cho CH. Herbal and natural supplements for improving sleep: A literature review. Psychiatry Investigation. 2024 Aug 2;21(8).

20. Onakpoya I, Spencer E, Heneghan C, Thompson M. The effect of green tea on blood pressure and lipid profile: A systematic review and meta-analysis of randomized clinical trials. Nutrition, Metabolism and Cardiovascular Diseases. 2014 Aug;24(8):823–36.

21. Zhao T, Li C, Wang S, Song X. Green Tea (Camellia sinensis): A Review of Its Phytochemistry, Pharmacology, and Toxicology. Molecules. 2022 Jun 18;27(12):3909.

22. Nawarathna GS, Ariyasinghe DI, Dassanayake TL. High-dose L-theanine–caffeine combination improves neurobehavioural and neurophysiological measures of selective attention in acutely sleep-deprived young adults: a double-blind, placebo-controlled crossover study. British Journal of Nutrition. 2025 Aug 12;1–10.

23. Kochman J, Jakubczyk K, Antoniewicz J, Mruk H, Janda K. Health Benefits and Chemical Composition of Matcha Green Tea: A Review. Molecules. 2020 Dec 27;26(1):85.

Assessed and Endorsed by the MedReport Medical Review Board