For Keira, who had already started puberty, the effect was to halt future development and stop her periods. She then moved on to cross-sex hormones – testosterone for women transitioning, oestrogen for males – and appointments at the adult clinic at Charing Cross Hospital in London.
Her voice deepened, she developed body hair and grew a beard. At the age of 21, she had her breasts removed. After realising her mistake, Keira had her last testosterone injection at the start of this year – yet she is still having to shave and is routinely mistaken for a man.
Now, she says, “I feel sick, I feel like I’ve been lied to. There’s no evidence for the treatments I’ve had, and they didn’t make me feel any better. It was maturity that did that.”