Hacker News Reader

And it is used medically in many countries for things like end-stage cancer pain.

In the UK it's given to some women during childbirth (although it's coyly known as "diamorphine"). https://www.babycentre.co.uk/a1026346/diamorphine

I really didn't know that is what it was. "Heroin" because it is dirty? "Diamorphine" because it is clean?

Because it is the "British Approved Name" of the substance apparently: