I have been taking knotweed resveratrol (1,000 mg of 50% knotweed trans-resveratrol) some time between mid 2014-2015 without the side effects (joints or GI) like some other people in longecity complained. But does emodin--at least in the "dosage" I mentioned or slightly higher--cause more long-term problems? I know emodin is an anthraquinone, and some anthraquinone may be hepatotoxic (to the point that China of all countries limited non-prescription use of He Shou Wu), but I haven't heard any specific issues of that nature regarding emodin.
This is quite important on my own choice between res/ptero, as this would eventually reflect as cost.