I do not have a pituitary gland, it was destroyed by a tumour 12 years ago. It is a total loss (very rare, usually some of it survives) and so I supplement all my hormones daily.
Earlier this year I had to stop taking sex-hormones for a medical reason, after a few days on no hormones the effects were intollerable, and got a lot worse. I became very lethargic, my brain stopped working normally (fog and forgetfulness), I lost power in my muscles, I felt depressed and I lost muscle and tone in my body. The human body needs at least some T and E to survive. I would not wish my worst enemy to go through it and would strongly advise against it. If you do not have any ovaries or testes then you need to supplement your hormone levels or your life will be one of pain, illness and very short.
I am also a microbial geneticist, and have followed the epigenetics discoveries very closely for over 20 years. There are some amazing things scientifically proven with epigenetics. Such as how well fed your grandmother was as a child can effect how you accumulate fat in your body - I mean wow, your grandmother.
The problem is, people with little understanding, take these valid scientific proofs and spin them to their own ends.
If you spend time up a mountain, then an epigenetic marker will allow your body to produce an enzyme that allows you to use oxygen better. This is caused by the low levels of oxygen in your system. The younger you are the quicker this epigenetic factor is created and applied. There is no evidence that if you think about living in a low oxygen environment it will have any effect. Epigenetics seem to be environmental in determinisation, only allowing parts of the genetic code to be expressed or supressed. Whilst thinking can and does change the brain patterns (after all that is the probable cause of how we generate memories) and can modulate hormones to some extent (If you feel fear, either real or imagined your cortisol can rise - the cause of modern day stress) there is no mechanism that exists to actually modify the genetic code. You cannot create hormones within your body without the endocrine gland responsible for that hormone. (and yes some hormones can be converted from others, but you need the precusor to start with).

The best explanation of epigenetics I ever heard was from an under-graduate, she equated it to a recipe for sweet shotcrust pastry, and the epigenetic marker was a piece of tape covering the sugar content of the ingredients. When it was in place, the recipe produced short-crust pastry, without it, sweet...  The recipe has not changed, just its expression has been modified.

As I said, the problem comes from people taking scientific fact and saying what if... Then saying well actually I think...
and from here we head into quackery. Repeated the world over from the earliest history.

That reminds me I have half a dozen bottles of snake oil if anyone's interested, guaranteed to do whatever you think it will (also know as a placebo).
Keep taking the drugs
Take care
Hugs
Sarah.

And that ^^^ is a phenomenal post. Thank you, Sarah. It repays re-reading several times.

I did try this for a week and, guess what? Yep ... I zeroed out on energy. I found myself falling asleep at any points during the day - sometimes it was extremely embarrassing such as when I was interviewing someone. I totally ran out of juice. I running on air.

So the anecdotal, and scientific, lesson appears to be that 1. yes epigenetics is amazing but 2. it won't control your hormones if you fail to supplement them.

 Essentially you will have all the symptoms of a eunuch.  Some positive, some negative.  I think you could achieve some of the permanent rewiring you are talking about (or something similar) but not without supplementing your diet with specific herbs or other supplements.   The ones I'm thinking of actually aren't hormonal, but cause a shift in your endocrine feedback loop