For me I noticed minor benefits after 4 days, and it took about 2 weeks for it to more fully kick in.
Personally the other side effects ended up with me going off it. The focus benefits stayed, though the low mood it turned out it was causing took 3 weeks to go away after I stopped.
my male genitals are not working well
This is a common side effect.
It’s either my alarm clock or 5.1 speakers, both of which would be somewhere over 20 years old.