I dunno, the most important thing is the EGCG percentage of Catechins in it, which is relavent to the polyphenol percentage... like for example Beyond-a-century.com has 98% polyphenol green tea.. 80% of those polyphenols are catechins and so much of the catechin percentage is EGCG's (main fat burning stimulating catechin in green tea) .. Beyond-a-century.com has the highest quality green tea extract I've ever seen anywhere.. so I suggest you get it from them, also it's dirt cheap.. something like 7 bucks for 50 grams.. and you can take about a gram/day perhaps split into 2 or 3 dosages... personally I take 500mg in the morning and 500mg in late afternoon.