Green tea extract

The supplied sources describe green tea as coming from the plant Camellia sinensis; green, black, and oolong teas all come from the same plant but are prepared using different methods, with green tea leaves steamed, pan fried, and dried but not fermented. Green tea extract is used for Cancer prevention, Coronary heart disease and Body weight.

Also called: Applied Nutrition (United States)

Pronunciation: pronunciation varies by local usage.

Generic name
green tea extract
Drug class
Dietary supplement (herbal product derived from Camellia sinensis)
Form
Tablets or capsules (as described in the sources). No dose, strength, or schedule is established by the supplied sources.
Route
Not established by the supplied sources. Green tea extract supplements are described in the sources as being taken by mouth (as tablets or capsules), but no administration instruction is provided.
Legal status
Not applicable / not established by the supplied sources. Dietary supplements are not approved by the U.S. Food and Drug Administration (FDA) before they are sold to the public. A topical ointment containing a specific green tea extract has been approved by the FDA as a prescription drug for external genital and perianal warts; that approval applies to that specific ointment, not to green tea extract supplements generally.

Availability and supply rules vary by country

Trade names by country: United States

Australia: · Full directory

What green tea extract is and how it works

The supplied sources describe green tea as coming from the plant Camellia sinensis; green, black, and oolong teas all come from the same plant but are prepared using different methods, with green tea leaves steamed, pan fried, and dried but not fermented. Green tea and its extracts are promoted as dietary supplements for losing weight, reducing blood cholesterol levels, and preventing chronic diseases such as heart disease and cancer. Herbal medicines, including green tea products sold as supplements, are one type of dietary supplement and are sold as tablets, capsules, powders, teas, extracts, and fresh or dried plants. (1) (2) (3)

The supplied sources state that although many studies have been done on green tea and its extracts, definite conclusions cannot yet be reached on whether green tea is helpful for most of the purposes for which it is used. The sources state that herbal medicines do not have to go through the testing that drugs do and that dietary supplements are not approved by the FDA before they are sold to the public. No dose, efficacy conclusion, or treatment plan is established by the supplied sources.

Mechanism of action: how green tea extract works

Not established by the supplied sources. The supplied sources name catechins and caffeine as constituents of green tea and its extracts, and state that green tea at high doses has been shown to reduce blood levels of nadolol, that green tea extract can reduce blood levels of atorvastatin, and that a study funded by the National Center for Complementary and Integrative Health showed an interaction between green tea and raloxifene. No mechanism, pharmacokinetics, or pharmacodynamics are described. (1) (2)

What is Green tea extract used for?

Promoted uses (evidence not established)

The supplied sources state that green tea and its extracts are promoted as dietary supplements for losing weight, reducing blood cholesterol levels, and preventing chronic diseases such as heart disease and cancer. However, the sources state that although many studies have been done, definite conclusions cannot yet be reached on whether green tea is helpful for most of the purposes for which it is used. These promoted uses are not established as effective by the supplied sources. (1)

Cancer prevention

The supplied sources state that studies of green tea and cancer in people have had inconsistent results and that, based on current evidence, it isn't possible to say whether green tea helps to prevent cancer. (1) (2)

Coronary heart disease

The supplied sources state that in Asian populations but not in Western populations, green tea consumption has been linked to a lower risk of coronary heart disease. This is a described association, not an established effect of green tea extract supplements. (1)

Body weight

The supplied sources state that the catechins and caffeine in green tea and its extracts may have a modest effect on body weight, and that the effects of green tea products may vary depending on the composition of the product and the individual's level of physical activity. (1)

Blood cholesterol

The supplied sources state that in randomized studies in which people consumed either a green tea product or a placebo, green tea reduced total cholesterol and low-density lipoprotein (LDL) cholesterol to a small extent, but did not affect high-density lipoprotein (HDL) cholesterol or triglycerides. Most of those studies evaluated green tea extract supplements rather than green tea as a beverage. (1)

FDA-approved topical green tea extract ointment (prescription drug)

The supplied sources state that the FDA has approved a topical ointment containing a specific green tea extract for the treatment of external genital and perianal warts, and that the FDA has approved this specific green tea extract ointment as a prescription drug for treating genital warts. This applies only to that specific approved ointment and is separate from the marketed dietary supplement products discussed above. No dosing or administration details are provided by the supplied sources. (1)

Before taking green tea extract

Do not take / not appropriate for

  • The supplied sources state that people with liver problems should not take green tea extracts. (green tea extract supplements) (2)
  • The supplied sources state that, if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products, because some herbs and medicines interact in harmful ways. (all green tea supplements and herbal products) (1) (3)

Tell your clinician about

  • The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products, because some herbs and medicines interact in harmful ways.
  • The supplied sources state that you should tell your health care provider about any herbal medicines you are taking.
  • The supplied sources state that if you are or might be pregnant, you should consult your health care provider for advice about caffeine intake, and that during pregnancy caffeine intake should not exceed moderate levels; green tea is a source of caffeine.
  • The supplied sources state that caffeine can pass to your infant through breast milk and that if you consume high levels of caffeine it can lead to symptoms such as fussiness and poor sleep patterns in your infant, while breastfeeding infants usually do not have adverse effects when mothers consume low-to-moderate levels of caffeine.
  • The supplied sources state that individuals with a specific variant of a gene that plays an important role in immune function appear to be especially susceptible to liver injury from green tea products, and that between 5 and 15 percent of Americans have this variant.
  • The supplied sources state that people with liver problems should not take green tea extracts.
  • The supplied sources state that experts suggest green tea extracts should be taken with food.
(1) (2) (3)

Green tea extract dosage and how to take it

  • The supplied sources do not provide a dose, strength, schedule, or duration for green tea extract supplements. No administration instruction is established by these sources.
  • The supplied sources state that experts suggest that green tea extracts should be taken with food.
  • The supplied sources state that green tea extract supplements are sold as tablets or capsules, and that green tea products may vary depending on the composition of the product.
  • The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products.
  • The supplied sources state that if you are thinking about using an herbal medicine, you should first get information on it from reliable sources.
  • The supplied sources state that dietary supplements are not approved by the U.S. Food and Drug Administration (FDA) before they are sold to the public, and that manufacturers and distributors of supplements are responsible for evaluating the safety and labeling of their products before marketing to ensure that they meet all regulatory requirements.
(1) (2) (3)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3)

Missed dose

Not established by the supplied sources. The supplied sources provide no dose, schedule, or missed-dose guidance for green tea extract supplements.

Overdose

Not established by the supplied sources. The supplied sources provide no overdose amount or overdose management guidance for green tea extract supplements.

Green tea extract side effects

The supplied sources state that no safety concerns have been reported for green tea consumed as a beverage by adults, but that green tea does contain caffeine, and that side effects are reported for green tea extract supplements. The sources state that, although uncommon, liver injury has been reported in some people who used green tea products, primarily green tea extracts in tablet or capsule form.

Nausea, constipation, abdominal discomfort, and increased blood pressure

What to notice: The supplied sources list these as side effects of green tea extract supplements.

What to do: The supplied sources do not specify an action for these effects. Discuss any concerns with your health care provider. (1)

Caffeine content

What to notice: The supplied sources state that green tea contains caffeine, that during pregnancy caffeine intake should not exceed moderate levels, and that high caffeine intake while breastfeeding can lead to symptoms such as fussiness and poor sleep patterns in the infant.

What to do: The supplied sources state that if you are or might be pregnant, you should consult your health care provider for advice about caffeine intake. (1)

Liver trouble (possible liver injury)

What to notice: The supplied sources name abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes) as symptoms of liver trouble. Liver injury has been reported in some people who used green tea products, primarily green tea extracts in tablet or capsule form, and is described as uncommon. Individuals with a specific variant of a gene that plays an important role in immune function appear to be especially susceptible, and between 5 and 15 percent of Americans have this variant.

What to do: The supplied sources state that users should discontinue use and consult a health care provider if they develop symptoms of liver trouble. Because no self-directed treatment-change instruction is given here, seek medical attention promptly and let the clinician you see advise on whether to continue or stop the product. (1) (2)

Serious warnings

Liver injury (hepatotoxicity) associated with green tea extract products — serious

Symptoms: Symptoms of liver trouble named in the supplied sources: abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes).

Action: The supplied sources state that users should discontinue use and consult a health care provider if they develop symptoms of liver trouble. This page does not instruct readers to stop a product themselves: seek medical attention promptly and let the clinician you see advise on whether to continue or stop. The supplied sources also state that people with liver problems should not take green tea extracts, and that experts suggest green tea extracts should be taken with food. (1) (2)

Increased blood pressure reported with green tea extract supplements — serious

Symptoms: The supplied sources list increased blood pressure as a side effect of green tea extract supplements.

Action: The supplied sources do not specify an action. Discuss blood-pressure concerns and all medicines with your health care provider. (1)

Products marketed as "natural" are not necessarily safe — caution

Symptoms: The supplied sources state that many people believe that products labeled "natural" are always safe and good for them, and that this is not necessarily true. The sources also state that herbal medicines do not have to go through the testing that drugs do and that some herbs, such as comfrey and ephedra, can cause serious harm.

Action: The supplied sources state that if you are thinking about using an herbal medicine, you should first get information on it from reliable sources, and that you should tell your health care provider about any herbal medicines you are taking. (3)

Interactions

Medicine or testEffectAction
Nadolol (a beta-blocker used for high blood pressure and heart problems)The supplied sources state that green tea at high doses has been shown to reduce blood levels and, therefore, the effectiveness of the drug nadolol.The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products. (1)
Atorvastatin (a cholesterol-lowering drug)The supplied sources state that green tea extract can reduce blood levels of the cholesterol-lowering drug atorvastatin.The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products. (1)
Raloxifene (used to treat osteoporosis)The supplied sources state that a study funded by the National Center for Complementary and Integrative Health showed an interaction between green tea and the drug raloxifene.The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products. (1)
Other medicines not individually named in the supplied sourcesThe supplied sources state that green tea may also interact with other medicines, and that some herbs and medicines interact in harmful ways. The supplied sources do not identify which other medicines.The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

The supplied sources state that during pregnancy caffeine intake should not exceed moderate levels and that green tea is a source of caffeine; if you are or might be pregnant, consult your health care provider for advice about caffeine intake. (1)

Breastfeeding

The supplied sources state that caffeine can pass to your infant through breast milk; if you consume high levels of caffeine, it can lead to symptoms such as fussiness and poor sleep patterns in your infant. However, breastfeeding infants usually do not have adverse effects when mothers consume low-to-moderate levels of caffeine. (1)

People with liver problems

The supplied sources state that people with liver problems should not take green tea extracts. (2)

People with a specific immune-function gene variant

The supplied sources state that individuals with a specific variant of a gene that plays an important role in immune function appear to be especially susceptible to liver injury from green tea products, and that between 5 and 15 percent of Americans have this variant. (1)

Monitoring

Before starting

  • The supplied sources state that if you are thinking about using an herbal medicine, you should first get information on it from reliable sources.
  • The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products, because some herbs and medicines interact in harmful ways.
  • The supplied sources state that you should tell your health care provider about any herbal medicines you are taking.
  • The supplied sources state that people with liver problems should not take green tea extracts.

During treatment

  • The supplied sources state that users should discontinue use and consult a health care provider if they develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes). This page routes that decision to a clinician rather than instructing readers to stop the product themselves.
  • The supplied sources state that if you take any type of medicine, you should talk with your health care provider before using green tea supplements or other herbal products.
  • The supplied sources state that green tea may interact with other medicines, and that some herbs and medicines interact in harmful ways.
(1) (2) (3)

Storage

Not established by the supplied sources. The supplied sources provide no storage instructions for green tea extract supplements.

Professional information

Clinician-facing context only. The supplied sources are consumer-facing NIH NCCIH and NLM MedlinePlus materials and provide no dosing, pharmacokinetic, or product-specific prescribing data for green tea extract supplements. Use current local product information and applicable regulation.

All regions

Indication: Any use of green tea extract supplements

Dose summary: Not established by the supplied sources. The supplied sources give no dose, strength, interval, or duration for green tea or green tea extract supplements. No dosing table is displayed.

Renal context: Not established by the supplied sources. The supplied sources provide no renal impairment guidance for green tea extract supplements.

Mechanism of action

Hepatic guidance

The supplied sources state that, although uncommon, liver injury has been reported in some people who used green tea products, primarily green tea extracts in tablet or capsule form; that individuals with a specific variant of a gene that plays an important role in immune function appear to be especially susceptible, and between 5 and 15 percent of Americans have this variant; that people with liver problems should not take green tea extracts; and that experts suggest green tea extracts should be taken with food. No impairment-specific dosing is provided.

Overdose note

Not established by the supplied sources. No overdose amount or overdose management guidance is provided. (1) (2)

Frequently asked questions

Does green tea extract help with weight loss?

The supplied sources state that the catechins and caffeine in green tea and its extracts may have a modest effect on body weight, and that the effects of green tea products may vary depending on the composition of the product and the individual's level of physical activity. The sources also state that definite conclusions cannot yet be reached on whether green tea is helpful for most of the purposes for which it is used. (1)

Does green tea prevent cancer?

The supplied sources state that studies of green tea and cancer in people have had inconsistent results and that, based on current evidence, it isn't possible to say whether green tea helps to prevent cancer. (1) (2)

Is green tea extract safe?

The supplied sources state that no safety concerns have been reported for green tea consumed as a beverage by adults, but that green tea does contain caffeine, and that side effects of green tea extract supplements include nausea, constipation, abdominal discomfort, and increased blood pressure. Although uncommon, liver injury has been reported in some people who used green tea products, primarily green tea extracts in tablet or capsule form. (1)

Does it matter whether I take green tea as a beverage or as a supplement?

The supplied sources distinguish the two: no safety concerns have been reported for green tea consumed as a beverage by adults, while the reported side effects and the reported cases of liver injury relate primarily to green tea extracts in tablet or capsule form. Most studies on blood cholesterol also evaluated green tea extract supplements rather than green tea as a beverage. (1)

Can green tea supplements interact with my medicines?

The supplied sources state that green tea at high doses has been shown to reduce blood levels and, therefore, the effectiveness of the drug nadolol; that green tea extract can reduce blood levels of the cholesterol-lowering drug atorvastatin; that a study funded by the National Center for Complementary and Integrative Health showed an interaction between green tea and raloxifene; and that green tea may also interact with other medicines. If you take any type of medicine, talk with your health care provider before using green tea supplements or other herbal products. (1)

Are dietary supplements approved by the FDA before they are sold?

The supplied sources state that dietary supplements are not approved by the U.S. Food and Drug Administration (FDA) before they are sold to the public, unlike drugs. The sources note that the FDA has approved a topical ointment containing a specific green tea extract as a prescription drug for treating genital warts; that approval applies to that specific ointment. Manufacturers and distributors of supplements are responsible for evaluating the safety and labeling of their products before marketing. (1) (3)

What should I do if I develop symptoms of liver trouble while taking a green tea extract?

The supplied sources state that users should discontinue use and consult a health care provider if they develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice (yellowing of the skin or eyes). Seek medical attention promptly and let the clinician you see advise on whether to continue or stop the product. (2)

Is it true that "natural" means safe?

The supplied sources state that many people believe products labeled "natural" are always safe and good for them, and that this is not necessarily true. Herbal medicines do not have to go through the testing that drugs do, and some herbs, such as comfrey and ephedra, can cause serious harm. (3)

What is the mechanism of action of green tea extract?

Not established by the supplied sources. The supplied sources name catechins and caffeine as constituents of green tea and its extracts, and state that green tea at high doses has been shown to reduce blood levels of nadolol, that green tea extract can reduce blood levels of atorvastatin, and that a study funded by the National Center for Complementary and Integrative Health showed an interaction between green tea and raloxifene. No mechanism, pharmacokinetics, or pharmacodynamics are described. (1) (2)

What is the generic name of Green tea extract?

The generic name is green tea extract. (1) (2) (3)

What class of drug is green tea extract?

Green tea extract is classed as: Dietary supplement (herbal product derived from Camellia sinensis). (1) (2) (3)

References

  1. Green Tea: Usefulness and SafetyNIH National Center for Complementary and Integrative Health · United States · dated 2025-02 · accessed 2026-10-13 · source 1
  2. Cancer and Complementary Health Approaches: What You Need To KnowNIH National Center for Complementary and Integrative Health · United States · dated 2021-10 · accessed 2026-10-13 · source 2
  3. Herbal Medicine (health topic)MedlinePlus, U.S. National Library of Medicine · United States · accessed 2026-10-13 · source 3

Brand names by country

Single-ingredient green tea extract names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

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This page provides general medicine information, not a diagnosis, prescription, treatment plan, or substitute for advice from your health care provider. Dietary supplements are not approved by the U.S. Food and Drug Administration for safety or effectiveness before sale. The supplied sources provide no dose, efficacy conclusion, or overdose guidance for green tea extract supplements.

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