How Much Caffeine Is Really in Your Green Tea? (2024)

Green tea is a popular type of tea made from the unoxidized leaves of theCamellia sinensisbush. It is less processed than other teas and is rich inantioxidants.

It naturally contains caffeine and is also available in a decaffeinated version. Green tea contains less caffeine than coffee and other caffeinated drinks.

Green tea has several possible health benefits, including improved brain function and a lower risk of several chronic health conditions.

Green Tea Has Caffeine: What to Know

Green tea contains caffeine, and the amount depends on the type of green tea. The average cup of green tea contains 3 calories and about 29 milligrams of caffeine.

Caffeine is a chemical naturally occurring in certain leaves, beans, and fruits. It acts as a central nervous system stimulant and boosts alertness. Caffeine fights feelings of fatigue by blocking the effects of a neurotransmitter called adenosine, which naturally builds up during the day and makes you feel tired.

Caffeine has been linked with improved alertness and mood. It may also boost brain function, metabolism health, and exercise performance.

Green Tea Forms

Green tea is available in many forms, including:

  • Bottled
  • Capsule supplements
  • Instant powder
  • Loose leaf
  • Single tea bags
  • Sweetened

Compared to Coffee

Green tea contains considerably less caffeine than coffee. An 8-ounce cup of brewed coffee contains about 133 milligrams (mg) of caffeine, while an 8-ounce cup of green tea contains 29 mg of caffeine. Espresso is high in caffeine and contains about 320 mg per serving.

A Word From Verywell

Green tea has less caffeine than the average cup of Joe. It can also pack a health punch while still delivering energy boosts.

AVIV JOSHUA, MS, MEDICAL EXPERT BOARD

How Much Caffeine Is Really in Your Green Tea? (1)

Compared to Other Teas

Green tea contains less caffeine than black tea. An 8-ounce cup of black tea contains 47 mg of caffeine. While green tea contains less caffeine, it may have a similar effect on alertness thanks to the amino acid L-theanine. This amino acid works with caffeine to improve alertness without the potential side effects like shakiness.

Other popular caffeinated drinks include soft drinks (23 to 27 mg of caffeine) and energy drinks (72 to 80 mg).

What Is Matcha?

Matcha is a powdered green tea with a higher caffeine content than other forms. It is also more concentrated than loose-leaf or bagged green teas.

When to Drink Caffeinated Green Tea

There is no better time of day than any other to drink caffeinated green tea, but if you are more sensitive to caffeine's effects, plan to drink it in the morning. Avoid drinking caffeinated tea in the afternoon or evening to prevent potential sleep problems.

Some people experience side effects of caffeine, including:

  • Anxiety
  • Insomnia
  • Irregular heartbeat (arrhythmia)
  • Restlessness

The recommended limit for most adults is 400 mg of caffeine per day. However, most healthcare providers advise people to limit their caffeine intake to 200 mg per day.

Benefits of Decaf Green Tea

Green tea has several possible health benefits. Drinking green tea regularly has been linked with lower rates of cancer, heart disease, and Alzheimer’s disease. Green tea may also boost weight loss efforts.

Data are inconsistent, and the topic requires more research, but green tea may protect against the following types of cancer:

  • Breast
  • Colorectal
  • Esophageal
  • Liver
  • Lung
  • Prostate
  • Skin

Green tea’s high antioxidant content may have a protective effect against cancer. Green tea may also protect against the following chronic health conditions:

  • Alzheimer’s disease: Drinking green tea regularly may reduce the risk of Alzheimer’s disease and dementia. Its neuroprotective effects come from its antioxidant levels.
  • Heart disease: Green tea’s anti-inflammatory effects may target free radicals and protect heart health.
  • High cholesterol: Drinking green tea has been linked to lower total cholesterol and low-density lipoprotein (LDL) cholesterol, considered “bad” cholesterol.
  • Skin inflammation: When applied directly to the skin, the antioxidant compounds in green tea may reduce inflammation (swelling, irritation, and pain).
  • Stroke: Drinking unsweetened green tea daily may reduce the risk of stroke thanks to its anti-inflammatory properties.

Infusion Time for Caffeinated Green Tea

Tea infusion time affects its caffeine content. This means that the longer you brew bagged or loose-leaf tea, the more concentrated your cup will be and the more caffeine it will contain.

Brewing green tea for a longer time will provide more caffeine. The caffeine content also goes up as the water temperature increases.Some research shows green tea made with older leaves contains less caffeine than teas made with fresh leaves.

It is important to note that drinking too much green tea is possible. Consuming large amounts of highly concentrated green tea has been linked to liver damage. It is safe for most healthy adults to drink up to eight cups of unsweetened green tea daily.

Summary

Green tea is a popular tea that naturally contains caffeine, a chemical in many plants, beans, and fruits. Caffeine boosts alertness and fights feelings of fatigue. Green tea is rich in antioxidants and linked with several possible health benefits, including improved brain health and weight loss. It may also protect against certain forms of cancer and heart disease.

Green tea contains less caffeine than coffee and other teas. One 8-ounce cup of green tea contains about 29 milligrams of caffeine. An 8-ounce cup of coffee has 95 milligrams of caffeine. If you are sensitive to the effects of caffeine, plan to drink green tea in the morning to avoid sleep issues.

24 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

  1. Heckman MA, Weil J, Gonzalez de Mejia E. Caffeine (1, 3, 7-trimethylxanthine) in foods: a comprehensive review on consumption, functionality, safety, and regulatory matters. J Food Sci. 2010;75(3):R77-R87. doi:10.1111/j.1750-3841.2010.01561.x

  2. Kurosaka C, Tagata C, Nakagawa S, Kobayashi M, Miyake S. Effects of green tea and roasted green tea on human responses. Sci Rep. 2024;14(1):8588. doi:10.1038/s41598-024-59383-y

  3. Tomata Y, Sugiyama K, Kaiho Y, et al. Green tea consumption and the risk of incident dementia in elderly Japanese: The Ohsaki Cohort 2006 study. Am J Geriatr Psychiatry. 2016;24(10):881-889. doi:10.1016/j.jagp.2016.07.009

  4. Huxley R, Lee CM, Barzi F, et al. Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus: a systematic review with meta-analysis. Arch Intern Med. 2009;169(22):2053-2063. doi:10.1001/archinternmed.2009.439

  5. U.S. Department of Agriculture. Beverages, tea, green, brewed, regular.

  6. McLellan TM, Caldwell JA, Lieberman HR. A review of caffeine's effects on cognitive, physical and occupational performance. Neurosci Biobehav Rev. 2016;71:294-312. doi:10.1016/j.neubiorev.2016.09.001

  7. Kazemzadeh-Narbat M, Annabi N, Tamayol A, Oklu R, Ghanem A, Khademhosseini A. Adenosine-associated delivery systems. J Drug Target. 2015;23(7-8):580-596. doi:10.3109/1061186X.2015.1058803

  8. Grosso G, Micek A, Castellano S, Pajak A, Galvano F. Coffee, tea, caffeine and risk of depression: A systematic review and dose-response meta-analysis of observational studies. Mol Nutr Food Res. 2016;60(1):223-234. doi:10.1002/mnfr.201500620

  9. Guest NS, VanDusseldorp TA, Nelson MT, et al. International society of sports nutrition position stand: caffeine and exercise performance. J Int Soc Sports Nutr. 2021;18(1):1. doi:10.1186/s12970-020-00383-4

  10. U.S. Department of Agriculture. Beverages, tea, black, brewed, prepared with tap water.

  11. Camfield DA, Stough C, Farrimond J, Scholey AB. Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis. Nutr Rev. 2014;72(8):507-522. doi:10.1111/nure.12120

  12. Saimaiti A, Zhou DD, Li J, et al. Dietary sources, health benefits, and risks of caffeine. Crit Rev Food Sci Nutr. 2023;63(29):9648-9666. doi:10.1080/10408398.2022.2074362

  13. Yang DJ, Hwang LS, Lin JT. Effects of different steeping methods and storage on caffeine, catechins and gallic acid in bag tea infusions. J Chromatogr A. 2007;1156(1-2):312-320. doi:10.1016/j.chroma.2006.11.088

  14. Curran CP, Marczinski CA. Taurine, caffeine, and energy drinks: Reviewing the risks to the adolescent brain. Birth Defects Res. 2017;109(20):1640-1648. doi:10.1002/bdr2.1177

  15. Reyes CM, Cornelis MC. Caffeine in the diet: Country-level consumption and guidelines. Nutrients. 2018;10(11):1772. doi:10.3390/nu10111772

  16. Kakutani S, Watanabe H, Murayama N. Green tea intake and risks for dementia, Alzheimer's disease, mild cognitive impairment, and cognitive impairment. Nutrients. 2019;11(5):1165. doi:10.3390/nu11051165

  17. Zamani M, Kelishadi MR, Ashtary-Larky D, et al. The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysis. Front Nutr. 2023;9:1084455. doi:10.3389/fnut.2022.1084455

  18. Ohishi T, Fukutomi R, Shoji Y, Goto S, Isemura M. The beneficial effects of principal polyphenols from green tea, coffee, wine, and curry on obesity. Molecules. 2021;26(2):453. doi:10.3390/molecules26020453

  19. Filippini T, Malavolti M, Borrelli F, et al. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database Syst Rev. 2020;3(3):CD005004. doi:10.1002/14651858.CD005004.pub3

  20. Sharma P, Montes de Oca MK, Alkeswani AR, et al. Tea polyphenols for the prevention of uvb-induced skin cancer. Photodermatol Photoimmunol Photomed. 2018;34(1):50-59. doi:10.1111/phpp.12356

  21. Xu R, Yang K, Li S, Dai M, Chen G. Effect of green tea consumption on blood lipids: a systematic review and meta-analysis of randomized controlled trials. Nutr J. 2020;19(1):48. doi:10.1186/s12937-020-00557-5

  22. Koch W, Zagórska J, Marzec Z, Kukula-Koch W. Applications of tea (Camellia sinensis) and its active constituents in cosmetics. Molecules. 2019;24(23):4277. doi:10.3390/molecules24234277

  23. American Heart Association. Green tea, coffee linked to lower death risk after stroke, heart attack.

  24. Lin YS, Tsai YJ, Tsay JS, Lin JK. Factors affecting the levels of tea polyphenols and caffeine in tea leaves. J Agric Food Chem. 2003;51(7):1864-1873. doi:10.1021/jf021066b

How Much Caffeine Is Really in Your Green Tea? (2)

By Carrie Madormo, RN, MPH
Madormo is a health writer with over a decade of experience as a registered nurse. She has worked in pediatrics, oncology, chronic pain, and public health.

See Our Editorial Process

Meet Our Medical Expert Board

Was this page helpful?

Thanks for your feedback!

What is your feedback?

How Much Caffeine Is Really in Your Green Tea? (2024)
Top Articles
Latest Posts
Recommended Articles
Article information

Author: Twana Towne Ret

Last Updated:

Views: 5912

Rating: 4.3 / 5 (44 voted)

Reviews: 91% of readers found this page helpful

Author information

Name: Twana Towne Ret

Birthday: 1994-03-19

Address: Apt. 990 97439 Corwin Motorway, Port Eliseoburgh, NM 99144-2618

Phone: +5958753152963

Job: National Specialist

Hobby: Kayaking, Photography, Skydiving, Embroidery, Leather crafting, Orienteering, Cooking

Introduction: My name is Twana Towne Ret, I am a famous, talented, joyous, perfect, powerful, inquisitive, lovely person who loves writing and wants to share my knowledge and understanding with you.