It’s awesome. Started taking it
It’s awesome. Started taking it when I took up mountain biking at 61 and almost immediately found I could go further, faster and climb better. I have, since retirement found I have time to study things that I’m interested in, and my concentration is greatly improved from before (wish this had been a thing back when I was in college!). Try it. You won’t be disappointed. I’ve been using it for a several years now, and plan on continuing.