Rez-V questions

Hey guys, i’ve been using a resveratrol supp. that is 250mg trans-resveratrol with other cofactors but it is just 50% standardized from japanese knotweed. Since its 500mg of knotweed, this leaves a lot of “emodin” a compound that naturally occurs in the weed that has some benefits, and some negative but mainly a lot of people who say Resveratrol hurt their stomach are probably reacting to the emodin that is rough on the gi tract.

My question is, what source does Biotest use to obtain their trans-resveratrol, is it emodin free? And how standardized is it?

Bump, did they ever answer this question anywhere?