DNA is literally code . Every human body has all the code to create a male or a female body . One gene , SRY , on the Y chromosome , triggers the formation of testes if it ' s activated , which it usually is when present . Then chromosomes stop doing much of anything that matters . The Y in XYbearing people , and one of the X chromosomes in XXbearing people , basically turn into inactive code libraries . Trans people are neurobiologically suited to the opposite developmental path . Trans men suffer on estrogen the same way cis men like Alan Turing or David Reimer did trans women suffer on testosterone like any other woman with a massive testosterone imbalance would . Medical transition is about correcting that balance and creating a body configuration that makes sense on a neurological level for the trans person . This is also why trans people typically do much much much better post transition our bodies work as normally as anyone else ' s , making sense to us and not poisoning us with a body warping and brain harming hormone balance . The reason my body looks clearly female nowadays is pretty simple every human body has hormone receptors for both sex hormones , and while I grew up on testosterone , I run on estrogen and that has changed pretty much every cell in my body . Medically , I can ' t be given male dosages or male reference rangestests or diagnosed with maletypical symptoms only my body runs in femaletypical ways . Socially , nobody calls me a man because my body very clearly bears the markers of female , estrogenic biologybreasts , curves , soft skin , relative hairlessness , and so on . I ' ll age with saggy breasts and stretch marks , not a bald scalp and back hair . Reproductively , I ' m sterile , and I do not produce the small gamete . So here ' s the philosophical question why would male be a useful descriptor for my body ? What useful function would that descriptor fulfill ? Clearly my body isn ' t a 100 % typical male or female body , but women with Turner ' s and Swyer ' s don ' t have those typical bodies either , and indeed some variation or gray area is to be expected in many many human bodies . For all normal intents and purposes , female is the best descriptor for my body and brain .