My doctor, who seems to know everything important about supplements (in other words, which are the best), says this product by Biotics Research, ResveraSirt-HP, is the best supplement of its kind on the market, By "best" he means the body absorbs it the best. It rejuvenates cells, and he gave me some amazing info on how it has rejuvenated cells in tests. He takes it, and I'm not sorry I now take it too. I'm 79, but don't feel old.