The Truth About Green Tea and Its Caffeine Content (2025)

Nutrition

February 4, 2025

Written By

Medically Reviewed by

Dr. Sarah Daglis ND

Updated On

February 28, 2025

The soothing aroma of green tea is enough to make anyone feel refreshed. Known for its delicate flavor and health-supporting properties, green tea has become a go-to drink for those seeking a balanced energy boost.

Unlike coffee, which delivers a quick jolt, green tea provides a more gradual lift—thanks to its unique combination of caffeine and calming compounds like L-theanine.

Understanding how much caffeine is in green tea can help you make informed choices about your daily routine. This article explores green tea's caffeine content, how it compares to coffee, and what it means for energy levels and well-being.

[signup]

Understanding Caffeine in Green Tea

Caffeine is a natural stimulant in various plants, including tea leaves, coffee beans, and cacao.

It belongs to a class of compounds called xanthines and works by blocking adenosine, a neurotransmitter that promotes relaxation and sleep.

Caffeine helps support alertness and energy levels, making it a popular ingredient in many beverages worldwide.

Chemical Properties and Effects on the Body

Caffeine is rapidly absorbed into the bloodstream, reaching peak levels within 45 minutes of consumption. It stimulates the central nervous system, promoting wakefulness and improving focus.

Caffeine can enhance cognitive function, physical performance, and metabolism in moderate amounts. However, excessive intake may lead to jitters, increased heart rate, and disrupted sleep patterns.

Caffeine in Natural Sources

Caffeine occurs naturally in several plant-based foods and beverages, including:

Coffee beans
Tea leaves
Cacao beans
Yerba mate and guayusa (herbal sources traditionally consumed in South America)

Each source varies in caffeine concentration, with factors like processing and preparation affecting the final content.

Caffeine Levels in Green Tea

Green tea contains moderate amounts of caffeine, typically 14 to 61 mg per cup (8 oz), depending on the variety and preparation method.

While lower than coffee, green tea still provides a noticeable energy boost. It is often described as smoother and longer-lasting due to the presence of L-theanine, an amino acid that promotes relaxation without drowsiness.

Factors Influencing Caffeine Content

The caffeine level in green tea can vary based on several factors:

Type of tea leaves – Younger leaves tend to have more caffeine than mature ones.
Processing methods – Some green tea varieties, like matcha, contain higher caffeine levels because the entire leaf is consumed.
Brewing time and temperature – Longer steeping times and hotter water extract more caffeine.
Tea bag vs. loose leaf – Tea bags, often made from smaller leaf particles, release caffeine faster than whole leaves.

Comparison with Other Beverages

When comparing caffeine content, green tea falls between low-caffeine herbal teas and high-caffeine coffee:

Health Benefits of Green Tea Caffeine

Caffeine in green tea offers more than just an energy boost—it also supports various aspects of physical and mental well-being.

Given its unique combination of caffeine and L-theanine, green tea may provide a smoother, more sustained effect than coffee. Here's how green tea caffeine can benefit your health:

Supports Alertness and Cognitive Function

The caffeine in green tea helps enhance focus, reaction time, and overall brain function.

Unlike coffee, which can cause sudden energy spikes and crashes, green tea's L-theanine works alongside caffeine to promote a balanced sense of alertness without jitters.

This combination also supports memory and mental clarity.

Promotes Metabolism and Fat Utilization

Research suggests that caffeine can help support metabolism by encouraging the body to use fat for energy.

Green tea, in particular, contains catechins, plant compounds that may enhance this effect. Caffeine and catechins may help maintain healthy energy levels throughout the day.

Enhances Physical Performance

Caffeine is a well-known natural performance enhancer. It stimulates the nervous system, promoting endurance and reducing the perception of fatigue.

Many athletes choose green tea for a mild pre-workout boost that doesn't lead to energy crashes.

Supports Cardiovascular Function

Moderate caffeine intake, such as that found in green tea, may promote heart health by helping maintain normal circulation and vascular function.

Additionally, the antioxidants in green tea, like EGCG (epigallocatechin gallate), may contribute to overall cardiovascular well-being.

Encourages a Balanced Mood

Unlike coffee, which can sometimes lead to restlessness or anxiety, green tea's caffeine interacts with L-theanine to promote a calm but focused state.

This balance may support mood regulation and reduce feelings of stress.

May Help Maintain Brain Health Over Time

Some research suggests that caffeine and the antioxidants in green tea may support cognitive health as people age. While more studies are needed, regular consumption of green tea has been associated with long-term brain function benefits.

Green tea's caffeine offers a mild, steady energy boost, making it a great alternative for those looking to stay alert and focused without the downsides of high-caffeine drinks.

Medical Implications of Green Tea Caffeine

While green tea caffeine offers several health-supporting benefits, it's essential to consider its potential medical implications.

Individual responses to caffeine vary; certain conditions or medications may influence how the body processes caffeine from green tea.

Effects on Sleep and Nervous System

Green tea contains less caffeine than coffee but can still impact sleep quality, especially if consumed later in the day.

Caffeine stimulates the nervous system, which may lead to:

Difficulty falling asleep or staying asleep (especially in caffeine-sensitive individuals)
Increased alertness, which may be beneficial in the morning but disruptive at night
A more gradual energy boost due to L-theanine, which may counteract the jittery effects of caffeine

Those sensitive to caffeine should limit their green tea intake in the late afternoon and evening to avoid sleep disturbances.

Potential Impact on Heart Health

Caffeine affects the cardiovascular system by temporarily increasing heart rate and blood pressure.

While moderate consumption is generally safe for most individuals, excessive intake of caffeinated beverages, including green tea, may not be suitable for:

Individuals with high blood pressure or heart rhythm irregularities
Those with caffeine sensitivity, which can cause palpitations or rapid heartbeat
People on blood pressure medications, as caffeine may interact with some antihypertensive drugs

Effects on Digestion and Nutrient Absorption

Caffeine can stimulate gastric acid production, which may lead to digestive discomfort in some people, particularly those prone to acid reflux or ulcers.

Additionally, green tea contains tannins, plant compounds that can:

Interfere with iron absorption from plant-based foods, potentially impacting individuals with iron deficiency
Cause mild stomach irritation if consumed on an empty stomach

Green tea is best consumed between meals rather than with iron-rich foods to minimize these effects.

Potential Interactions with Medications

Caffeine and green tea compounds may interact with certain medications, including:

Blood thinners (anticoagulants such as warfarin): Green tea contains vitamin K, which may impact the effectiveness of blood-thinning medications.
Stimulant medications: Caffeine can enhance stimulant effects, potentially leading to increased heart rate or nervousness.
Antidepressants and anxiety medications: Some medications that affect brain chemistry may interact with caffeine, influencing mood or causing restlessness.

Those taking prescription medications should consult their provider before significantly increasing their green tea intake.

Considerations for Pregnancy and Breastfeeding

Pregnant and breastfeeding individuals should monitor caffeine intake, as excess consumption may:

Cross the placenta and affect fetal development
Be passed into breast milk, potentially affecting an infant's sleep patterns
Contribute to dehydration if consumed excessively

The American College of Obstetricians and Gynecologists (ACOG) recommends limiting caffeine intake to 200 mg or less per day during pregnancy, including caffeine from green tea, coffee, and other sources.

Green Tea vs Coffee: Which is Better?

For many, the choice between green tea and coffee comes down to personal preference. While both provide a natural boost, their unique compounds affect the body differently.

Green tea offers a gentler, sustained lift with calming L-theanine, while coffee delivers a quick jolt of energy. Understanding their differences can help you determine the best match for your lifestyle.

Comparing Caffeine Content

Green Tea: 14 to 61 mg per cup (8 oz), depending on the variety and preparation.
Coffee: 60–100 mg per cup, making it a more potent stimulant.

Coffee has nearly three times the caffeine of green tea, leading to a more immediate energy boost.

Energy Boosting Potential

Coffee provides a fast-acting energy spike due to its high caffeine content.
Thanks to L-theanine, green tea offers a steadier boost, which promotes calm alertness without sudden crashes.

Jitters and Crash: Which Is Gentler?

Coffee's high caffeine can sometimes lead to jitters, restlessness, and energy crashes.
With its L-theanine, green tea provides a smoother, more sustained energy without the same intensity of side effects.

Antioxidant Powerhouse

Both green tea and coffee contain antioxidants, but green tea is especially rich in EGCG (epigallocatechin gallate), a powerful compound linked to cellular health and metabolism support.

Polyphenols in Green Tea

Green tea contains catechins, a group of polyphenols with potent antioxidant properties, whereas coffee is rich in chlorogenic acids, which may support metabolic health.

Overall Health Benefits Comparison

Green Tea: Supports metabolism, brain function, and cardiovascular health with fewer caffeine-related side effects.
Coffee: Offers stronger stimulation and may support brain function and metabolism but can cause energy crashes in some people.

[signup]

Key Takeaways

Green tea contains 20–50 mg of caffeine per cup, significantly less than coffee. It can provide a smoother and longer-lasting energy boost due to the L-theanine content, which promotes relaxation without drowsiness.
Unlike coffee, which may cause jitters and energy crashes, green tea's balanced combination of caffeine and L-theanine enhances focus, metabolism, and physical performance while supporting a calm but alert state.
While green tea offers various health benefits, excessive intake may impact sleep, digestion, heart health, and medication interactions, making moderation key, especially for caffeine-sensitive individuals or those with certain medical conditions.

The information in this article is designed for educational purposes only and is not intended to be a substitute for informed medical advice or care. This information should not be used to diagnose or treat any health problems or illnesses without consulting a doctor. Consult with a health care practitioner before relying on any information in this article or on this website.

Learn more

No items found.

Lab Tests in This Article

No lab tests!

Watch Live Classes on our

References

ACC. (2024). Chronic High Caffeine Consumption Impacts Heart Rate, BP Post Activity, Heightens Risk For CVD - American College of Cardiology. American College of Cardiology. https://www.acc.org/Latest-in-Cardiology/Articles/2024/08/14/16/39/Chronic-High-Caffeine-Consumption-Impacts-Heart-Rate-BP

Anderson, S. (2022, September 14). This is What Happens to Your Body When You are Dehydrated. Rupa Health. https://www.rupahealth.com/post/this-is-what-happens-to-your-body-when-you-are-dehydrated

Bertagna, B. (2023, December 28). Health Benefits of Green Tea and How to Include It in Your Diet. Rupa Health. https://www.rupahealth.com/post/health-benefits-of-green-tea-and-how-to-include-it-in-your-diet

Bryant, A. (2024, August 2). Understanding Arrhythmias: Types, Symptoms, Diagnosis, and Treatment. Rupa Health. https://www.rupahealth.com/post/arrhythmias-basics-types-symptoms-diagnosis-treatment

Caffeine. (1994). PubMed; Organization of Teratology Information Specialists (OTIS). https://www.ncbi.nlm.nih.gov/books/NBK582613/

Cheng, T. O. (2007). Green tea may inhibit warfarin. International Journal of Cardiology, 115(2), 236. https://doi.org/10.1016/j.ijcard.2006.04.003

Chin, J. M., Merves, M. L., Goldberger, B. A., Sampson-Cone, A., & Cone, E. J. (2008). Caffeine content of brewed teas. Journal of Analytical Toxicology, 32(8), 702–704. https://doi.org/10.1093/jat/32.8.702

Christie, J. (2023a, February 14). Vitamin K's health benefits. Rupa Health. https://www.rupahealth.com/post/vitamin-ks-role-in-the-body

Christie, J. (2023b, November 30). Caffeine For Diabetes: A Comprehensive Overview. Rupa Health. https://www.rupahealth.com/post/caffeine-for-diabetes-a-comprehensive-overview

Cloyd, J. (2023a, February 21). A Functional Medicine GERD Protocol. Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-gerd-protocol

Cloyd, J. (2023b, April 10). A Functional Medicine Hypertension Protocol. Rupa Health. https://www.rupahealth.com/post/functional-medicine-hypertension-protocol

Cloyd, J. (2023c, July 26). A Functional Medicine Iron Deficiency Anemia Protocol: Comprehensive Testing, Therapeutic Diet, and Supplements. Rupa Health. https://www.rupahealth.com/post/a-functional-medicine-iron-deficiency-anemia-protocol-comprehensive-testing-therapeutic-diet-and-supplements

Cloyd, J. (2024, January 25). The Role of Green Tea Extract in Metabolic Syndrome Management. Rupa Health. https://www.rupahealth.com/post/the-role-of-green-tea-extract-in-metabolic-syndrome-management

Dietz, C., & Dekker, M. (2017). Effect of Green Tea Phytochemicals on Mood and Cognition. Current Pharmaceutical Design, 23(19), 2876–2905. https://doi.org/10.2174/1381612823666170105151800

Dodd, F. L., Kennedy, D. O., Riby, L. M., & Haskell-Ramsay, C. F. (2015). A double-blind, placebo-controlled study evaluating the effects of caffeine and L-theanine both alone and in combination on cerebral blood flow, cognition and mood. Psychopharmacology, 232(14), 2563–2576. https://doi.org/10.1007/s00213-015-3895-0

Gardiner, C., Weakley, J., Burke, L. M., Roach, G. D., Sargent, C., Maniar, N., Townshend, A., & Halson, S. L. (2023). The effect of caffeine on subsequent sleep: A systematic review and meta-analysis. Sleep Medicine Reviews, 69(101764), 101764. https://doi.org/10.1016/j.smrv.2023.101764

Giesbrecht, T., Rycroft, J. A., Rowson, M. J., & De Bruin, E. A. (2010). The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness. Nutritional Neuroscience, 13(6), 283–290. https://doi.org/10.1179/147683010x12611460764840

Harvard T.H. Chan. (2020, July 30). Caffeine. The Nutrition Source. https://nutritionsource.hsph.harvard.edu/caffeine/

How much coffee can I drink while I'm pregnant? (n.d.). Www.acog.org. https://www.acog.org/womens-health/experts-and-stories/ask-acog/how-much-coffee-can-i-drink-while-pregnant

Institute of Medicine (US) Committee on Military Nutrition Research. (2001). Caffeine for the Sustainment of Mental Task Performance: Formulations for Military Operations. National Library of Medicine; National Academies Press (US). https://www.ncbi.nlm.nih.gov/books/NBK223808/

Jeon, J.-S., Kim, H.-T., Jeong, I.-H., Hong, S.-R., Oh, M.-S., Yoon, M.-H., Shim, J.-H., Jeong, J. H., & Abd El-Aty, A. M. (2019). Contents of chlorogenic acids and caffeine in various coffee-related products. Journal of Advanced Research, 17, 85–94. https://doi.org/10.1016/j.jare.2019.01.002

Jurgens, T. M., Whelan, A. M., Killian, L., Doucette, S., Kirk, S., & Foy, E. (2012). Green tea for weight loss and weight maintenance in overweight or obese adults. The Cochrane Database of Systematic Reviews, 12(12), CD008650. https://doi.org/10.1002/14651858.CD008650.pub2

Khasnabis, J., Rai, C., & Roy, A. (2015). Determination of Tannin Content by Titrimetric Method from Different Types of Tea. Journal of Chemical and Pharmaceutical Research, 7(6), 238–241. https://www.jocpr.com/articles/determination-of-tannin-content-by-titrimetric-method-from-different-types-of-tea.pdf

Lin, Y.-S., Tsai, Y.-J., Tsay, J.-S., & Lin, J.-K. (2003). Factors Affecting the Levels of Tea Polyphenols and Caffeine in Tea Leaves. Journal of Agricultural and Food Chemistry, 51(7), 1864–1873. https://doi.org/10.1021/jf021066b

Mayo Clinic Staff. (2022, April 26). Caffeine content for coffee, tea, soda and more. Mayo Clinic. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20049372

Meyboodi, M., Mohammadpour, A. H., Emami, S. A., & Karbasforooshan, H. (2020). Drug Interactions of Green Tea. Journal of Pharmaceutical Care, 196–203. https://doi.org/10.18502/jpc.v8i4.5243

Nehlig, A. (2022). Effects of Coffee on the Gastro-Intestinal Tract: a Narrative Review and Literature Update. Nutrients, 14(2), 399. https://doi.org/10.3390/nu14020399

Nobre, A. C., Rao, A., & Owen, G. N. (2008). L-theanine, a natural constituent in tea, and its effect on mental state. Asia Pacific Journal of Clinical Nutrition, 17 Suppl 1(1), 167–168. https://pubmed.ncbi.nlm.nih.gov/18296328/

Reddy, V. S., Shiva, S., Manikantan, S., & Ramakrishna, S. (2024). Pharmacology of Caffeine and Its Effects on the Human Body. European Journal of Medicinal Chemistry Reports, 10(10), 100138. https://doi.org/10.1016/j.ejmcr.2024.100138

Robinson, K. (2024, December 26). Yerba Mate 101: History, Benefits, and Brewing Essentials. Rupa Health. https://www.rupahealth.com/post/yerba-mate-101-history-benefits-and-brewing-essentials

Rodak, K., Kokot, I., & Kratz, E. M. (2021). Caffeine as a Factor Influencing the Functioning of the Human Body—Friend or Foe? Nutrients, 13(9), 3088. https://doi.org/10.3390/nu13093088

Sweetnich, J. (2023, June 20). Top Evidence-Based Supplements and Herbs for Restful Nights, Backed by Specialty Lab Testing to Personalize Treatment. Rupa Health. https://www.rupahealth.com/post/top-evidence-based-supplements-and-herbs-that-help-with-sleep-plus-specialty-lab-testing-that-can-help-identify-which-one-is-best-for-your-patients

Szopa, A., Poleszak, E., Wyska, E., Serefko, A., Wośko, S., Wlaź, A., Pieróg, M., Wróbel, A., & Wlaź, P. (2015). Caffeine enhances the antidepressant-like activity of common antidepressant drugs in the forced swim test in mice. Naunyn-Schmiedeberg’s Archives of Pharmacology, 389(2), 211–221. https://doi.org/10.1007/s00210-015-1189-z

Te, G. (2001). Caffeine and exercise: metabolism, endurance and performance. Sports Medicine (Auckland, N.Z.). https://pubmed.ncbi.nlm.nih.gov/11583104/

Unno, K., & Nakamura, Y. (2021). Green Tea Suppresses Brain Aging. Molecules, 26(16), 4897. https://doi.org/10.3390/molecules26164897

Weinberg, J. L. (2023, December 26). The Power of Polyphenols: Functional Medicine's Antioxidant Superstars. Rupa Health. https://www.rupahealth.com/post/the-power-of-polyphenols-functional-medicines-antioxidant-superstars

Werba, J. P., Misaka, S., Giroli, M. G., Shimomura, K., Amato, M., Simonelli, N., Vigo, L., & Tremoli, E. (2018). Update of green tea interactions with cardiovascular drugs and putative mechanisms. Journal of Food and Drug Analysis, 26(2), S72–S77. https://doi.org/10.1016/j.jfda.2018.01.008

Williams, J. L., Everett, J. M., D'Cunha, N. M., Sergi, D., Georgousopoulou, E. N., Keegan, R. J., McKune, A. J., Mellor, D. D., Anstice, N., & Naumovski, N. (2019). The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review. Plant Foods for Human Nutrition, 75(1). https://doi.org/10.1007/s11130-019-00771-5

Wolfram, S. (2007). Effects of Green Tea and EGCG on Cardiovascular and Metabolic Health. Journal of the American College of Nutrition, 26(4), 373S388S. https://doi.org/10.1080/07315724.2007.10719626

Xanthine Derivatives. (2012). PubMed; National Institute of Diabetes and Digestive and Kidney Diseases. https://www.ncbi.nlm.nih.gov/books/NBK548950/

Yashin, A., Yashin, Y., Wang, J., & Nemzer, B. (2013). Antioxidant and Antiradical Activity of Coffee. Antioxidants, 2(4), 230–245. https://doi.org/10.3390/antiox2040230

Order from 30+ labs in 20 seconds (DUTCH, Mosaic, Genova & More!)

We make ordering quick and painless — and best of all, it's free for practitioners.

Thanks for subscribing!

Oops! Something went wrong while submitting the form.

Thanks for subscribing!

Oops! Something went wrong while submitting the form.