In some people, green tea can cause stomach upset and constipation. Green tea extracts have been reported to cause liver and kidney problems in rare cases. Green tea is POSSIBLY UNSAFE when taken by mouth long-term or in high-doses. It can cause side effects because of the caffeine.
EGCG side effects are seldom observed during human trials. Nevertheless, if you are consuming green tea extract, it is important to pay attention to the quality of .