August 23, 2019

Safety Assessment of Green Tea Based Beverages and Dried Green Tea Extracts as ‎Nutritional Supplements

Epigallocatechin 3-gallate (EGCG), the major catechin present in green tea, is suspected of being responsible for liver toxicity reported in humans consuming food supplements. Intake of EGCG with green tea infusions and GTE-based beverages is up to about 450mg EGCG/person/day in Europe and higher in Asia.


Consumption of green tea is not associated with liver damage in humans, and green tea infusion and GTE-based beverages are considered safe in the range of historical uses. In animal studies, EGCG's potency for liver effects is highly dependent on conditions of administration. The safety of green tea infusions and green tea extract (GTE)-based products is reviewed regarding catechins. Use of NOAELs -Highest dose at which there was not an observed toxic or adverse effect (2)- from bolus administration to derive a tolerable upper intake level results in acceptable EGCG-doses lower than those from one cup of green tea.


NOAELs from toxicity studies applying EGCG with diet/split of the daily dose are a better point of departure for risk characterization.

In clinical intervention studies, liver effects were not observed after intakes below 600mg EGCG/person/day. Thus, a tolerable upper intake level of 300mg EGCG/person/day is proposed for food supplements. (1)






1- Dekant, W., Fujii, K., Shibata, E., Morita, O., & Shimotoyodome, A. (2017). Safety assessment of green tea based beverages and dried green tea extracts as nutritional supplements. Toxicology Letters, 277, 104-108. Retrieved from




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