Emodium is a fairly potent cathartic. At this level, the amount of emodium in one of your pills would have most people jumping on and off the toilet for 3 days.
There are ways to reduce the emodium content, but even at 1 to 3% many people will be uncomfortably "loose." Ten miligrams is too much emodium for some people. Until proven otherwise, I will assume this is a problem with all high-dose resveratrol products on the market. This information should be on the label
Anyone can get a Chinese 50% resveratrol extract for about $125 a kilo and pack it into capsules and put them in a bottle with a pretty label; what is critical is the emodium content (among other things.)
I read a while back that the metabolites of Quercetin may block the benefits of Resveratrol
Don't mean to beat my own drum here, but I probably know as much if not more on the subject of resveratrol than anyone around.
Given everything I know, I can only recommend Biotest. They are the ONLY company out there with near 100 percent pure trans resveratrol. It is expensive. This is because making and producing pure RSV isn't cheap.