Mine had me apply to lower abs and inner thigh. The idea is that in normal men, there is fat there and the testo will be absorbed, held and released more evenly.
This doesn't hold up with anyone with low bfr ... so then I was thinking that lower abs is in line with the reproductive system ... and inner thigh is blood gateway up through the torso.
And then I am told that you can transmit via touch so wash your hands.
Confusing.
IME .... lower abs seems smartest. As for the coin purse ... gels sting.