Finasteride was inspired by men with a mutation that prevents them from transcribing 5ar type 2. They never lose their hair or develop normal sized prostates, so they don't get BPH or PC either, and they actually have elevated levels of T relative to the GP.

Finasteride or dutasteride at normal doses will make you nearly or completely (respectively) 2-5ar deficient in adulthood.

The FDA PII study on dutasteride, which blocks nearly all of 2-5ar and half of 1-5ar at normal doses (0.5mg/day) and nearly all of 1-5ar at higher doses (2.5+ mg/day), shows that the more you inhibit 5ar the more T you necessarily have -- both because it is not being reduced into DHT locally, and because the lack of DHT seems to stimulate the endogenous production of T systemically -- and the better your results will be in terms of hair loss prevention.

So men on dutasteride and 2-5ar deficient men prove that T alone cannot cause hair loss: it's just not androgenic enough. Maybe it can continue to miniaturize already miniaturizing follicles once the ball is rolling, but that's just speculation.

As we know, steroids get an anabolic /androgenic ratio that is relative to T. Let's take Anavar as an example. It's less than half as androgenic as T and more than three times as anabolic. It will not be reduced by 5ar, and it will suppress endogenous T production.

So here's my point: T is not androgenic enough to cause hair loss on its own, though I guess it could finish off a damaged follicle. By taking something like var, which is even less androgenic than T, you are actually reducing the overall androgenic stimulus at your follicles by suppressing endogenous production.

Even gear that can be reduced by 5ar into something more androgenic (e.g. I think dbol can become 5ar-dbol) might still be less androgenic than T, and therefore would be preferable to T in terms of hair preservation.

If nothing else, I'm sure it could help with regrowth. Once again, if you look at the PII dut study (in the context of the pharmocokinetics of dutasteride) you see that even when all of 2-5ar is gone if you continue to reduce the androgenic stimulus from 1-5ar's DHT you see more hair regrowth. So, reducing the androgenic stimulus beyond 1% baseline 2-5ar deficient "maintenance" levels at least helps with regrowth.

I'm new here, so I don't know if someone has brought this up before, but it's been in the back of my mind for some time now.

I know that sounds confusing.