I don't supplement with Boron. Noticed the testosterone effect while cleaning the marble floor with boric acid and bare hands (don't worry, it does not sting, less acid than vinegar). I am a lady but I felt its rush all the same.
Boric acid is perfect for cleaning floors, cockroaches do not dare to cross them after that. Since I do a fair bit of cleaning, I assume I don't need extra boron.
This boric acid is also the most important part of my anti-cockroach equipment.
I make boric acid sweets for them to take back to their nests. Haven"t seen a live cockroach for more than two years.