... 50%,Polygonum cuspidatum extract KOSHER certified 1. SourceA. Grape resveratrol : Contain unique ingredient of trans ε-viniferin (ε-viniferin ... , 5-200 μM), a dimer of resveratrol, emodin free, to distinguish from the ... Polygonum cuspidatum extract(resveratrol 50% is extract from a Chinese traditional medicine Polygonum cuspidatum which contain stable, ...