WHY DO YOU NEED DHEA?

DHEA converts to Estradiol and Testosterone. If you are already injecting testosterone, what is the benefit of DHEA?

It has other roles but mostly not understood. Has some roles in the brain and when guys have heart attacks, lower DHEA is predictive of lower 1 year survivability. So its thought to have some cardiod-vascular benefits.

You are correct, it only feeds the sex hormone cascade in a diagram if hormone cascades.