The present study was designed to examine whether high doses of
green tea has any harmful effect on
thyroid physiology. For this purpose
green tea extract was administered orally to male albino rats for 30 days at doses of 1.25 g%, 2.5 g% and 5.0 g%, respectively. Similarly, pure catechin was administered at doses of 25, 50 and 100mg/kg body weight which is equivalent to above doses of green tea extract.