The jury is out in terms of its efficacy, or lack thereof. [1,2]
[1] https://www.health.harvard.edu/blog/resveratrol-the-hype-con...
[2] https://www.health.harvard.edu/blog/diet-rich-resveratrol-of...
Re. David Sinclair [3]:
"Despite his enthusiasm, published scientific research has not yet demonstrated the molecule works in humans as it does in mice. Sinclair, however, has a considerable financial stake in his claims being proven correct, and has lent his scientific prowess to commercializing possible life extension products such as molecules known as “NAD boosters.”
His financial interests include being listed as an inventor on a patent licensed to Elysium Health, a supplement company that sells a NAD booster in pills for $60 a bottle. He’s also an investor in InsideTracker, the company that he says measured his age."
[3] https://khn.org/news/a-fountain-of-youth-pill-sure-if-youre-...