The only facts I have are from my specific experiences at company and battalion level as OIC for said urinaylysis, while most were not 100% they were random and we did have a rotating table of substances that were not disclosed that woud be tested for, predomintaely substances such as MDMA, LSD etc etc along with the common THC and cocaine, pharmaceuticals etc. Granted I was not a career Soldier I did however know of as you stated from a higher level instances of individuals being tested for steroid use I dont believe this is the terminology used however. What substance I do not know. and to what level of depth I do not know. I would assume, as I thought I could that this would be something predetermined once someone reached this point of testing.
While comparatively it was not as common as other substances I can speak from experience I know it happened. Hope that clears anything up. I also am fully aware that it is common and not as big a concern or deal for many in the service as with the point I agree within an environment geared on aspects such as readiness, athletics, strength, ability to react and do it efficiently at a moments notice it usually had benefits and therefore was never really at least to myself a big deal if and when someone did use unless it had accompanying negative circumstances to work, or family.
Hope that clears anything up.
As for the HRT, as I was not on it in the service you are correct I could not verify personally, but I could go do research if I wanted to check, this comment was made purely from the idea that since things like fertility treatments, birth control and other healtcare such as this are available and also due to the fact that since it is TRICARE and HRT is offered under TRICARE I do not see why it would not be available for a soldier who medically required it. I currently work at the VA and due to privacy I can not give specifics, but can say that TRICARE from my experience does and will cover this along with VA healthcare. I also look at the demographics here and if I am worng that would suck due to the fact that the Military is predominately male and falls withing the age group. just a thought.
While facts can be obtained likely through gathering numbers of cases over a period of time or substances tested for over years or in a multitude of ways, I am trying to supply information based on my persoanl experience while it may not be the same as others it is given to provide insight and facts based upon my knowledge and experience. Does this make it wrong...no does it mean it is the same across every unit and branch surely not. What it does give however is knowledge to those reading this about my experience and hopefully proviudes someone with some help or insight into the matter.