I know that long term opiod use affects (lowers) testosterone levels, and where my subdural hematoma occured, at the top of my brain stem, put direct pressure on my pituitary and the gland underneath it (sorry, forget it's name) which regulates testosterone and other hormones, So I've got two strikes against me.
I've taken testosterone, and it has helped, in a couple ways.

But, my doc wants bloodwork now to start using it again, and his concern is mostly (as I understand it) my blood levels, as I should also be on a Statin.. Testosterone affects that too. So, as MRS D said, we really should be tested before just taking testosterone.
(which usually comes in a Gel form, or Gel in a patch).

Be well,

Pete
asb