Well, of course there is, by this community's standards. (Look at the safety concerns raised over melatonin*!)

Is it poison? Probably not. There are sporadic small human studies, and there's general considerations like researchers being drawn to resveratrol because of longevity benefits in populations, which would be inconsistent with it being dangerous.

If I may extrapolate, you are asking 'is the expected utility of resveratrol supplements positive?' The answer is probably yes, but the effect is so small (and resveratrol so expensive) that just about anything would offer better marginal gains. Fish oil or vitamin D, for example.

* no, I'm not bitter - more bemused