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Does Green Tea Have Caffeine?

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Green tea is not naturally caffeine-free. Green tea contains an average of 29 milligrams (mg) of caffeine in an 8-ounce cup, but the amount can vary. Black tea typically has more caffeine at 47 mg per 8 ounces.

Green tea and black tea are the most common caffeinated teas. Both are produced from Camellia sinensis leaves. Black and green tea leaves differ in the degree of oxidation (a chemical reaction) they are exposed to before drying. In addition, black tea is fermented (sugar molecules are broken down through natural processes), and green tea is not.

Research supports various health benefits of green tea, including weight loss, improved cognition, and cancer prevention.

This article covers green tea’s caffeine content, decaffeinated tea, green tea’s health benefits, and more.

PeopleImages / Getty Images

 

 

How Much Caffeine Is in Green Tea?

Caffeine is the most widely consumed stimulant. It is naturally found in tea and coffee. Coffee contains up to 3 times more caffeine than green tea.

One 8-ounce cup of brewed green tea contains 20 to 44 mg of caffeine. Bagged teas often have more caffeine than loose teas, but the amount of caffeine will vary depending on the tea plant and other factors, such as growing conditions, processing, and brewing.

Caffeine is found naturally in the plants used to make coffee, tea, and chocolate. It is available in various plants and trees used to make beverages and flavorings, such as:

Caffeine may also be added as an ingredient to various foods and beverages. Caffeine is also available in dietary supplements.

Sources of Caffeine
 Caffeine Source Serving Size Amount of Caffeine
Brewed coffee 8 ounces 95 mg
Instant coffee 8 ounces 60 mg
Espresso 1 shot/1.5 ounces 65 mg
Regular/diet dark cola 12 ounces 40 mg
Mountain Dew 12 ounces 55 mg
Black tea 8 ounces 47 mg
Green tea 8 ounces 29 mg (20–44 mg)
Arizona (bottle) Green Tea 8 ounces 29.4 mg
Lipton Signature Blend Green Tea 8 ounces 6–30 mg
Herbal tea 8 ounces 0 mg
Decaffeinated tea 8 ounces 2 mg
Dark chocolate 1 ounce 24 mg
Energy drinks 8 ounces 85 mg
Caffeine supplements 1 tablet 200 mg

 

What Affects How Much Caffeine Is in Green Tea?

The caffeine content in green tea varies depending on the type, processing, quality, and how long you steep the tea bag or tea leaves (soak in boiling water), as follows:

  • Type: The variety of green tea can influence its caffeine content. For example, powdered matcha tea tends to have more caffeine than other types of green tea.
  • Brewing time: The longer the tea is brewed and steeped, the more caffeine will be extracted from the tea bags or leaves.
  • Leaf age/processing: Younger, smaller tea leaves will have more caffeine than older ones. The length of processing may also influence caffeine amounts.
  • Tea quality: Higher quality green tea brands will have more caffeine because younger, smaller tea leaves are used to make them.

 

Is There Decaffeinated Green Tea?

Decaffeinated green tea might be an alternative if you want to enjoy the benefits of green without caffeine.

Most decaffeinated green tea is labeled as “naturally decaffeinated.” Decaffeinating involves removing most of the caffeine from the leaves while trying to maintain its flavor and health benefits. Decaffeination is done using a chemical process.

Even after being decaffeinated, green tea and other decaffeinated teas will still contain small amounts of caffeine. If you react strongly to caffeine, you may want to avoid decaffeinated teas altogether.

You might consider the following alternative non-caffeinated beverages if you are trying to avoid caffeine:

  • Herbal teas: Ginseng, ginger, rosemary, sage, etc.
  • Plain water: Bottled or tap
  • Carbonated water
  • Milk: Dairy, soy, almond, oat, rice, etc.
  • Fruit and vegetable juices
  • Lemonade
  • Root beer (most brands, but check the label as some contain added caffeine)
  • Caffeine-free homemade sodas
  • Apple cider: Cold or hot

 

Does Green Tea Have Health Benefits?

Green tea has been touted for its health benefits—many of which are backed by research.

Such health benefits of green tea include:

    • Weight loss: Green tea contains a catechin (a type of plant compound) called epigallocatechin gallate, which research suggests may help reduce body weight. Catechins may promote small changes in metabolism that may aid with weight loss.
    • Cognition benefits: Green tea has ingredients that may improve brain function, cognition, and brain function. These ingredients include l-theanine and caffeine.
    • Reduced cancer risk: Some evidence suggests drinking green tea may reduce the risk for some types of cancer, including lung cancer and ovarian cancer.
    • Improved oral health: Some evidence suggests that drinking tea or using green tea extract could be linked to better oral health.
    • Heart health protection: The catechins in green tea have anti-inflammatory properties, which researchers believe target free radicals (destructive unstable molecules) while inhibiting enzymes (substances that cause certain chemical reactions) that promote oxidation and inducing antioxidant enzymes (that reduce harm from free radicals) to protect heart health.

 

  • Lowers cholesterol: Green tea consumption may help lower total cholesterol and low-density lipoprotein (LDL) cholesterol (“bad cholesterol”).
  • May help you live longer: Green tea may contain protective active substances that help reduce the risk of death from all causes.

 

How Can Caffeine Affect You?

Caffeine has a wide variety of health benefits, but it also has adverse side effects.

Positive effects of caffeine consumption include:

  • Alertness: Caffeine can help improve alertness by blocking neurotransmitters (chemicals that communicate between nerve cells) that make you feel tired.
  • Improved blood sugar levels: Some evidence suggests caffeine consumption may regulate sugar levels.
  • Improved metabolism: Caffeine affects how fats are generated and broken down in the body.
  • Enhanced exercise performance: Research has shown that caffeine can enhance exercise performance, especially for aerobic exercise.

Caffeine is associated with several health issues, including:

    • Sleep issues: Caffeine can block the effects of the neurotransmitter adenosine, which regulates sleep. This can affect sleep quality, especially when consumed close to bedtime.
    • Anxiety: In people sensitive to caffeine, doses of 400 mg of caffeine per day can cause nervousness and speed up heart rate. People who have an underlying anxiety or panic disorder have a higher risk of this effect from caffeine.
    • Increased blood pressure and blood flow: Caffeine can stimulate the heart and increase blood pressure and blood flow, especially for people who do not typically consume it. It may cause palpitations (sensations that your heart is racing or pounding) or extra beats from the heart, shakiness, dizziness, nervousness, or irritability. Fortunately, most of these effects are temporary. However, if symptoms last a half hour or longer or worsen, you should seek immediate medical attention.
    • Pregnancy troubles: Caffeine consumption in pregnancy can lead to high caffeine levels in the fetus. The American College of Obstetricians and Gynecologists (ACOG) recommends moderate levels of caffeine during pregnancy—no more than 200 mg or about 2 cups of coffee—as anything higher has been linked to the risk of miscarriage or preterm birth.

 

  • Digestive problems: Some people find that caffeine can lead to stomach troubles, including stomachache and diarrhea.
  • May lead to dependence: Regular intake of caffeine may lead to dependence. If you abruptly stop consuming caffeine, you may experience withdrawal symptoms, such as fatigue, irritability, and headaches.
  • Drug interactions: Caffeine may interact with some medicines. Medications that may interact negatively with caffeine include some cardiac drugs, anti-seizure medicines, levothyroxine (thyroid hormone), and blood thinners. Discuss your caffeine intake with a healthcare provider when being prescribed medications.

 

How Much Is Too Much?

A daily intake of 400 mg of caffeine or less is usually considered safe for most healthy adults. That is equal to about 14 cups of green tea. The limits for teens and children are much longer at 100 and 2.5 mg, respectively.

Caffeine toxicity can occur if someone consumes 1 gram (g), equal to 1,000 milligrams, or more of caffeine in one dose. Consuming 2 g or more at one time is believed to be dangerous and requires hospitalization. Doses of 5 g or more could be lethal.

Toxicity is rare with the consumption of caffeinated drinks. Higher levels are typically seen with caffeine supplements.

A Word From Verywell

If you’re looking to cut caffeine in your diet due to preference or sensitivity, decaf might be your way to go. However, note that “decaf” doesn’t mean no caffeine, just less.

 

Summary 

Green tea is made from Camellia sinensis leaves. The amount of caffeine in green tea varies between blends and averages about 29 mg per cup. This is considered smaller than black tea and other caffeinated beverages. The caffeine content in green tea varies based on brand and type, processing quality, and steeping time.

If you want to enjoy the benefits of green tea but want to avoid caffeine, you might consider its decaffeinated version. However, it should be noted that decaffeinated tea may still contain small amounts of caffeine.

Scientific research supports the belief that green tea has many health benefits. These benefits include boosting alertness, improving cognition and heart health, reducing cancer risk, and promoting weight loss.

A daily intake of 400 mg of caffeine is considered safe for most adults. The limits for children and teenagers are much lower.

While caffeine toxicity is rare, some people should avoid caffeine. This includes people who are caffeine-sensitive, pregnant people, people with anxiety and sleep troubles, and those taking medications that may interact negatively with caffeine.

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. FoodData Central. Beverages, tea, green, brewed, regular.
  2. FoodData Central. Beverages, tea, black, brewed, prepared with tap water.
  3. Gonçalves Bortolini D, Windson Isidoro Haminiuk C, Cristina Pedro A, de Andrade Arruda Fernandes I, Maria Maciel G. Processing, chemical signature and food industry applications of Camellia sinensis teas: an overviewFood Chem X. 2021;12:100160. doi:10.1016/j.fochx.2021.100160
  4. Harvard T.H. Chan School of Public Health. Caffeine.
  5. Donlao N, Ogawa Y. The influence of processing conditions on catechin, caffeine and chlorophyll contents of green tea (Camelia sinensis) leaves and infusions. LWT. 2019;116:108567.doi:10.1016/j.lwt.2019.108567
  6. Food and Drug Administration. Spilling the beans: How much caffeine is too much?
  7. Rodak K, Kokot I, Kratz EM. Caffeine as a factor influencing the functioning of the human body-friend or foe? Nutrients. 2021;13(9):3088. doi:10.3390/nu13093088
  8. Nutritionix. Arizona green tea.
  9. Lipton. Signature blend green tea 40 tea bags.
  10. Serdar G, Demir E, Sökmen M. Sequential green extraction of caffeine and catechins from green tea. Int. J. Second. Metab. 2019;6(3):283-291. doi:10.21448/ijsm.629151
  11. Ohishi T, Fukutomi R, Shoji Y, Goto S, Isemura M. The beneficial effects of principal polyphenols from green tea, coffee, wine, and curry on obesityMolecules. 2021;26(2):453. doi:10.3390/molecules26020453
  12. Mancini E, Beglinger C, Drewe J, Zanchi D, Lang UE, Borgwardt S. Green tea effects on cognition, mood and human brain function: a systematic reviewPhytomedicine. 2017;34:26-37. doi:10.1016/j.phymed.2017.07.008
  13. Abe SK, Inoue M. Green tea and cancer and cardiometabolic diseases: a review of the current epidemiological evidence. Eur J Clin Nutr. 2021;75(6):865-876. doi:10.1038/s41430-020-00710-7
  14. Vyas T, Nagi R, Bhatia A, Bains SK. Therapeutic effects of green tea as an antioxidant on oral health- a reviewJ Family Med Prim Care. 2021;10(11):3998-4001. doi:10.4103/jfmpc.jfmpc_943_21
  15. Zamani M, Kelishadi MR, Ashtary-Larky D, et al. The effects of green tea supplementation on cardiovascular risk factors: A systematic review and meta-analysisFront Nutr. 2023;9:1084455. doi:10.3389/fnut.2022.1084455
  16. Abe SK, Saito E, Sawada N, et al. Green tea consumption and mortality in Japanese men and women: a pooled analysis of eight population-based cohort studies in JapanEur J Epidemiol. 2019;34(10):917-926. doi:10.1007/s10654-019-00545-y
  17. Farias-Pereira R, Park CS, Park Y. Mechanisms of action of coffee bioactive components on lipid metabolismFood Sci Biotechnol. 2019;28(5):1287-1296. doi:10.1007/s10068-019-00662-0
  18. Guest NS, VanDusseldorp TA, Nelson MT, et al. International Society of Sports Nutrition position stand: caffeine and exercise performanceJ Int Soc Sports Nutr. 2021;18(1):1. doi:10.1186/s12970-020-00383-4
  19. National Center for Complementary and Integrative Health. Green tea.
  20. Reichert CF, Deboer T, Landolt HP. Adenosine, caffeine, and sleep-wake regulation: state of the science and perspectives. J Sleep Res. 2022;31(4):e13597. doi:10.1111/jsr.13597
  21. UC Davis Health. Q&A: What effect does caffeine have on your heart?
  22. James JE. Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers-to-beBMJ Evid Based Med. 2021;26(3):114-115. doi:10.1136/bmjebm-2020-111432
  23. Johns Hopkins Medicine. New insight into caffeine use disorder.
  24. Hladun O, Papaseit E, Martín S, Barriocanal AM, Poyatos L, Farré M, Pérez-Mañá C. Interaction of energy drinks with prescription medication and drugs of abuse. Pharmaceutics. 2021;13(10):1532. doi:10.3390/pharmaceutics13101532
  25. Lai YW, Huang SM. Tea consumption affects the absorption of levothyroxine. Front Endocrinol (Lausanne). 2022;13:943775. doi:10.3389/fendo.2022.943775
  26. Zafar S, Ashraf MM, Ali A. Effect of caffeine on anti-clotting activity of warfarin in healthy male albino rabbits. Pak J Pharm Sci. 2018;31(2(Suppl.)):611-616
  27. Temple JL, Bernard C, Lipshultz SE, Czachor JD, Westphal JA, Mestre MA. The safety of ingested caffeine: a comprehensive review. Front Psychiatry. 2017;8:80. doi:10.3389/fpsyt.2017.00080
  28. Willson C. The clinical toxicology of caffeine: a review and case study. Toxicol Rep. 2018;5:1140-1152. doi:10.1016/j.toxrep.2018.11.002
Lana Barhum

By Lana Barhum

Barhum is a freelance medical writer with 15 years of experience with a focus on living and coping with chronic diseases.

 

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