I found it didn't help much with my focus, memory or concentration (my main issues) but it did a great job helping me chill out a bit. It was pretty subtle, but I felt calmer with much less of the constant anxiety and panicking about not meeting expectations, so I think it did good things for my mental health overall.
It took a few days to kick in but I did stop eventually due to side effects. First one I noticed was that it gave me an upset stomach, nausea, and reduced my appetite, especially if I took it on an empty stomach. My heart rate increased a bit, not so much at rest but any time I moved around it would speed up a lot more than it ought to. The real dealbreaker for me was erectile dysfunction, though... I was having a lot of trouble keeping it up, orgasm wasn't as pleasurable, and my sex drive dropped like a rock.
I have heard these kinds of hardware issues can go away after a while for most people so I tried to stick with it, but I didn't see any improvement after a couple months so I stopped taking it in the end. Had a pretty gnarly headache and felt like a horny teenager again for a couple days after stopping, but that all cleared up pretty quick and everything's back to normal now.
Payouts must be good for that kind of blatant loyalty.