Nathan Verhelst died Monday in a Brussels hospital surrounded by friends after requesting assistance to die in a case that has been highly publicised in Belgium, which became only the second country in the world after the Netherlands to legalise euthanasia in 2002.
"He died in all serenity," said doctor Wim Distlemans, who told the daily Het Laatste Nieuws that he won permission to be euthanised because "we could clearly say he was in unbearable psychological distress."
Nathan was born Nancy into a family of three boys where he was rejected by parents who had wanted another son, said the newspaper who spoke to him on the eve of his death.
He underwent three operations to change sex between 2009 and 2012 but felt uncomfortable with his body, saying he still had breasts and that his penis was "a failure".
"The first time I saw myself in the mirror I felt an aversion for my new body," he said. "I had happy moments but in the end the balance tipped to the wrong side."
Jacqueline Herremans, a member of the national euthanasia committee, told RTL television that he had been examined by two doctors, including a psychiatrist, to make sure he was not suffering from a temporary depression.
While there were only six cases of euthanasia recorded on psychological grounds in 2004, there were 33 in 2011 and 52 last year.
Euthanasia is currently legal only for those over 18 but parliament is considering calls to legalise the euthanasia of minors, so long as they are judged capable of deciding for themselves.
Belgium recorded a record 1,432 cases of euthanasia in 2012, up 25 percent from the previous year. They represented two percent of all deaths.
There are strict conditions governing the act including that patients must be capable, conscious and have to give a "voluntary, considered and repeated" request to die.