Matcha and Green Tea as Drinks: Research, Caffeine and Liver Cautions
Matcha and brewed green tea as drinks: what research and NCCIH say, caffeine, pregnancy, and why green tea extract capsules carry liver-injury cautions the drink does not.
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Drink or extract: the first thing to know
Green tea comes from the leaves of Camellia sinensis (L.) Kuntze. [1] NCCIH says no safety concerns have been reported for green tea consumed as a beverage by adults, but that liver injury, although uncommon, has been reported in some people who used green tea products. [2] The NCCIH wording is about products, and it does not say that the drink caused these cases. This page is about the drink, including powdered matcha. Extract and capsule safety is in Green Tea, and the three forms are compared in Green Tea vs Matcha vs Green Tea Extract. Results for a drink do not transfer to an extract, and the reverse is also true.What matcha is
Matcha is a powdered green tea made from plants shaded during growth, which raises the leaf content of theanine, caffeine, chlorophyll and catechins. [3] One review calls matcha the best condensed source of the main green tea catechins; that is a statement about composition, not proof of benefit. [3] Proper evidence not found in the sources we read for the caffeine content of a typical matcha serving; labels and preparation differ. Matcha is described as abundant in caffeine. [4]What the research shows
| Question | What the source found | Strength of evidence | Population and form studied |
|---|---|---|---|
| Deaths from any cause, tea overall | Highest versus lowest tea intake linked to 10% lower all-cause mortality; the greatest all-cause reduction was at about 2 cups a day. [5] | Observational association | Prospective cohorts; tea types not separated |
| Blood pressure and lipids, trials | A review of 14 trials of green or black tea (798 people, 4 to 24 weeks) found no significant effects, and said trials were underpowered. [6] | Mixed | Healthy and at-risk adults |
| Blood pressure, people with elevated pressure | A meta-analysis of 5 trials found systolic pressure down 4.81 mmHg and diastolic down 1.98 mmHg; green tea looked stronger than black. [7] | Promising but limited | Green and black tea drinks |
| Heart disease | NCCIH says green tea has been linked to lower coronary heart disease risk in Asian but not in Western populations. [2] | Observational; inconsistent | Population studies |
| Cancer | NCCIH calls the overall results inconsistent. [2] | Insufficient evidence | Population studies |
| Body weight | NCCIH says catechins and caffeine in green tea and its extracts may have a modest effect on body weight. [2] | Promising but limited; drink and extract not separated | Mixed |
| Stress and anxiety, matcha | One small trial of 39 people compared a matcha chosen for its ingredient ratios with a placebo matcha, and found lower anxiety in the first group. [4] | Preclinical plus one small trial; promising but limited | Mice and 39 adults; research-formulated matcha |
Not shown: that matcha or green tea prevents or treats any disease. Label evidence plainly when you read health claims.
Related
Green, Black, White and Oolong Tea · Black Tea · CoffeeFrequently asked questions
Is matcha healthier than green tea?
Not shown in the sources we read. A review describes matcha as a concentrated source of catechins, but no head-to-head trials of health outcomes were found. [3] Proper evidence not found (searched PubMed for matcha versus brewed green tea).
Can green tea harm the liver?
NCCIH says liver injury is uncommon but has been reported with green tea products, and that no safety concerns have been reported for the beverage in adults. [2] Extracts are covered in Green Tea.
How much caffeine is in matcha?
Matcha is described as abundant in caffeine, but a typical serving amount was not found in the sources we read. [4] For brewed green tea the FDA lists 37 mg per 12 ounces. [8]
Does green tea help with weight?
NCCIH says catechins and caffeine in green tea and its extracts may have a modest effect on body weight; the sources did not separate the drink from extracts. [2]
Is green tea safe in pregnancy?
NCCIH says caffeine should not exceed moderate levels during pregnancy. [2] Ask your clinician about your own limit.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and who should ask a clinician
- Caffeine: green tea contains caffeine. [2] The FDA lists 37 mg in a 12-ounce cup of green tea. [8] Official limits are on Caffeine in Foods and Drinks.
- Pregnancy: NCCIH says caffeine intake during pregnancy should not exceed moderate levels. [2] One review of green and white tea suggests reducing tea in the last trimester. [9] Ask your clinician.
- Liver: NCCIH reports uncommon liver injury in some people who used green tea products. [2] If you use green tea products and have any symptoms of liver trouble, contact a clinician promptly.
- Medicines: NCCIH reports that high-dose green tea can reduce the effect of nadolol and that green tea extract can lower blood levels of atorvastatin, and advises talking with a health care provider before using green tea supplements. [2] Interactions for the drink at usual amounts: not described in the sources we read. See How Interactions Work.
- Quality: powders and supplements vary; see Quality Testing and Certifications.
References
- GBIF Secretariat. GBIF Backbone Taxonomy species match for Camellia sinensis (L.) Kuntze, Theobroma cacao L., Coffea arabica L. and Coffea canephora Pierre ex A.Froehner (all status ACCEPTED, exact match). Read 2026-10-23.
- National Center for Complementary and Integrative Health (NCCIH). Green Tea. Read 2026-10-23.
- Health Benefits and Chemical Composition of Matcha Green Tea: A Review. Molecules 2020. PMID 33375458. Read 2026-10-23.
- Stress-Reducing Function of Matcha Green Tea in Animal Experiments and Clinical Trials. Nutrients 2018. PMID 30308973. Read 2026-10-23.
- Tea consumption and risk of all-cause, cardiovascular disease, and cancer mortality: a meta-analysis of thirty-eight prospective cohort data sets. Epidemiol Health 2024. PMID 38938012. Read 2026-10-23.
- Short-Term Tea Consumption Is Not Associated with a Reduction in Blood Lipids or Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. J Nutr 2020. PMID 33188386. Read 2026-10-23.
- The effects of regular consumption of green or black tea beverage on blood pressure in those with elevated blood pressure or hypertension: a systematic review and meta-analysis. Complement Ther Med 2020. PMID 32507441. Read 2026-10-23.
- U.S. Food and Drug Administration. Spilling the Beans: How Much Caffeine Is Too Much?. Page current as of 08/28/2024. Read 2026-10-23.
- Tea's anti-obesity properties, cardiometabolic health-promoting potentials, bioactive compounds, and adverse effects: A review focusing on white and green teas. Food Sci Nutr 2023. PMID 37823174. Read 2026-10-23.