Green Tea / EGCG

Also known by these names

  • Chinese tea
  • Matcha tea
  • Green tea extract
  • Green tea polyphenols
  • Epigallocatechin gallate (EGCG)

The active constituent in green tea is epigallocatechin-3-gallate (EGCG).

Treating the Cancer

Working against cancer growth or spread, improving survival, or working with other treatments or therapies to improve their anticancer action

Lab and Animal Evidence

Key Points

  • The active constituent in green tea is epigallocatechin-3-gallate (EGCG).
  • BCCT’s interest in green tea and EGCG derives from its protective qualities. Evidence, especially from China, suggests that green tea may protect against cancers of the colon and stomach.
  • Some evidence shows that green tea’s relatively weak anticancer activity increases in combination with anticancer drugs.
  • Drinking green tea appears safe at regular, habitual and moderate use.
  • Green tea use may not be compatible with some conditions and circumstances.

Laboratory studies show an anticancer effect of green tea or its main constituent EGCG, although a few clinical trials and population surveys show mixed results.

A 2017 review found the weak inhibitory activity of EGCG increased synergistically in combination with anticancer drugs.1

Breast cancer effects:

  • Limited growth, proliferation and adhesion and induced cell death (apoptosis) of breast cancer cells2
  • Restored estrogen receptor gene expression, interfered with tumor growth rate and other anticancer effects in breast cancer cell lines3
  • Synergistic interaction with tamoxifen or raloxifene in treating estrogen receptor-positive and estrogen receptor-negative breast cancer, without interacting with aromatase inhibitors or fulvestrant4
  • Sensitized tumor cells to chemotherapy and radiotherapy in lab studies, but also reduced the effect of the chemotherapy drug bortezomib (Velcade), used primarily in multiple myeloma5

EGCG amplified the toxicity of cisplatin in ovarian cancer cells6 and enhanced sensitivity of ovarian cancer cells to cisplatin.7

A 2018 review found that EGCG enhances the effectiveness of several treatments with glioma:8

  • Irradiation
  • Some chemotherapy drugs: temozolomide, carmustine, cisplatin
  • Other cancer treatments: tamoxifen and TNF-related apoptosis-inducing ligand

Reducing Risk

Reducing the risk of developing cancer or the risk of recurrence

Epidemiological Evidence

A number of studies in China have suggested that high intake may protect against cancers of the colon, esophagus and stomach.910

Lab and Animal Evidence

Reviews of studies published in 2017 have concluded that EGCG prevents or inhibits human cancer.11

Green tea extract reduced markers of oxidative stress and inflammation in blood from cancer patients12  and reduced breast carcinogenesis or proliferation in cell studies..13


Drinking green tea appears safe at regular, habitual and moderate use (3-9 cups per day).14

Green tea use may not be compatible with some conditions and circumstances such as pregnancy or chemotherapy treatment. Green tea/EGCG also interacts with several pharmaceutical drugs and the absorption of iron.15

EGCG reduces the effect of the chemotherapy drug bortezomib (Velcade), used primarily in multiple myeloma, in cell studies.16

Further cautions and warnings regarding use of green tea/EGCG are noted.17  Please see Memorial Sloan Kettering Cancer Center’s About Herbs: Green Tea for more information and seek the advice of a trained health professional if indicated.


BCCT does not recommend therapies or doses, but only provides information for patients and providers to consider as part of a complete treatment plan. Patients should discuss therapies with their physicians, as contraindications, interactions and side effects must be evaluated. Levels of active ingredients of natural products can vary widely between and even within products. See Quality and Sources of Herbs, Supplements and Other Natural Products.

Specific dosing recommendation are available from these sources:

Integrative Programs, Protocols and Medical Systems

For more information about programs and protocols, see our Integrative Programs and Protocols page.
  • Programs and protocols
    • Alschuler & Gazella complementary approaches18
      • Bladder cancer
      • Brain cancer
      • Breast cancer
      • Colorectal cancer
      • Gastric cancer
      • Head and neck cancer
      • Kidney cancer
      • Leukemia
      • Liver cancer
      • Lung cancer
      • Melanoma
      • Ovarian cancer
      • Pancreatic cancer
      • Prostate cancer
      • Soft tissue sarcomas
      • Detoxification
      • Immune-enhancing
      • Insulin resistance reversal
    • Block program19
      • Surgical support program: angiogenic inhibition
      • Radiation support formula
      • Targeted molecular therapy
      • Anticancer diet plan: antioxidant, blocking tumor-fueling enzymes
      • Combination circulatory support supplement
      • Remission maintenance program: chemopreventive
    • Lemole, Mehta & McKee protocols20
      • Bladder cancer
      • Breast cancer
      • Colorectal cancer
      • Endometrial cancer
      • Leukemia
      • Lung cancer
      • Lymphoma
      • Melanoma
      • Prostate cancer
      • Thyroid cancer
    • McKinney protocols21
      • Bladder cancer
      • Breast cancer
      • Brain/nerve cancer
      • Carcinoid/neuroendocrine cancer
      • Cervical cancer
      • Colorectal cancer
      • Esophageal cancer
      • Head and neck cancer
      • Kidney cancer
      • Leukemia
      • Lymphoma
      • Melanoma
      • Multiple myeloma
      • Myelodysplastic syndrome
      • Sarcoma
      • Skin cancer
      • Stomach cancer
      • Thyroid cancer
      • Uterine cancer
  • Traditional systems

Written by Nancy Hepp, MS, and reviewed by Laura Pole, RN, MSN, OCNS; Most recent update April 10, 2019.

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