The main focus of the shampoo is to stimulate hair growth and not stop DHT. So if you decide to use that shampoo make sure you use it along with a DHT inhibitor.
I use it but I can't tell if it responsible for anything positive.
It's a part of my morning shower and it's pretty cheap (the LE version, slightly weaker but recommended by Dr. P for those on a budget, is only $18.71 shipped on Amazon: here).