I've been taking Niacinamide + Resveratrol for over 2 years. Honestly, I don't see any positive effect, but neither I see any negative effects either. Given I'm 40 now, I'm not 100% sure if this is a negative or a positive outcome. For example, without any supplementation, maybe I should've aged more... but how can I know for sure. My point it, as long as the supplement is orthomolecular, the negative side of spending a few dollars per month is well-justified.