Resveratrol's mechanism of action (as I understand it), is sirtuin activation. In some circumstances it can lead to mitochondrial fission via SIRT1 and this would lead to a short term rise in ROS, but long term would likely lead to healthier mitochondria and lower ROS. But it's not so simple as this, as in some conditions (i.e. after a large meal) SIRT4 reduces cellular proliferation and increases mitochondrial fusion and fat storage. So it seems it can have different effects depending on the state of feeding.
I think on balance resveratrol is a healthy supplement that isn't very bioavailable. When I've taken it before it generally makes me leaner (but I took it on an empty stomach), and it aids my cognition and exercise performance. But it reduces my sex drive, so I never stay on it for long. I have more recently experimented with resveratrol (and pterostilbene, which has a longer half life) in a well fed state (see https://www.longecit...s/#entry857309)and haven't suffered from the reduced sex drive. I have a working theory (sorry, no reference) that resveratrol is great for overweight people, but if you're already lean, it may well (as an aromatase inhibitor) reduce your estrogen to such an extent it reduces your sex drive (men need a certain level of estrogen).
