We know from Harry Potter and the Philosopher's Stone that if you kill a unicorn to drink its blood, the blood carries a terrible curse:

"Only one who has nothing to lose, and everything to gain, would commit such a crime. The blood of a unicorn will keep you alive, even if you are an inch from death, but at a terrible price. You have slain something so pure and defenceless to save yourself, you will have but a half-life, a cursed life, from the moment the blood touches your lips."

However, we also see in Harry Potter and the Goblet of Fire, that, at least at Hogwarts, unicorns may be, although purportedly difficult to do, caught.

Could a captured unicorn then simply be medicinally and humanely 'bled' (i.e. cut, but not killed) and its blood used in that way, without the user falling victim to the curse? In otherwords, is it the blood that is cursed no matter what or is it, as Firenze states, the act of murder that curses the blood?

  • 10
    @RemyLebeau what if it's used to cure someone else? Say, what if an unicorn is attecked by a giant, you and your friend manage to fight it off, but your friend gets a fatal wound in the process. Can you use some unicorn blood from the wounds caused by the giant to save your friend? Or any unicorn blood gotten thru violent means is cursed?
    – user68762
    Jan 14, 2018 at 6:06
  • 1
    Wow! Now, that's a question.. Jan 14, 2018 at 16:18
  • 3
    As a general rule, magic in HP doesn't permit that sort of loophole. So probably it doesn't work at all unless the unicorn is dead, and even if you weren't the one to kill it, you'd be desecrating the body. That's just a guess though, wouldn't have the foggiest idea where to look for a canon answer. Jan 14, 2018 at 20:22
  • 1
    Bonus question: does it also work on muggles?
    – user13267
    Jan 15, 2018 at 3:38
  • 1
    @Morrigan Based on my answer, no. The giant could be saved from death but not your friend. Jan 15, 2018 at 14:22

1 Answer 1


Almost certainly not.

It's not exactly clear-cut but I'd suggest that someone who drank unicorn blood without killing the unicorn would get neither the curse nor the benefits which Firenze is describing.

The full context of the passage makes this clearer.

"Harry Potter, do you know what unicorn blood is used for?"
"No," said Harry, startled by the odd question. "We've only used the horn and tail-hair in Potions."
"That is because it is a monstrous thing, to slay a unicorn," said Firenze. "Only one who has nothing to lose, and everything to gain, would commit such a crime. The blood of a unicorn will keep you alive, even if you are an inch from death, but at a terrible price. You have slain something pure and defenceless to save yourself and you will have but a half life, a cursed life, from the moment the blood touches your lips."
(Philosopher's Stone, Chapter 15, The Forbidden Forest).

Note that throughout this passage that Firenze is only referring overtly to slain unicorns. The prospect of a healthy, domesticated unicorn being 'farmed', as it were, for its blood is not one which is in prospect for Firenze. It seems that both the benefit (immortality) and the curse are tied to the act of slaying the unicorn. That's why the horn and the hair are used in Potions and wandcraft but not the blood. The horn and the hair can be extracted innocently from the carcass of a unicorn which has had a natural death. So can the blood, of course - but in that instance the blood is really just a messed-up cocktail with no true value. It's the slaying of the unicorn which makes the blood yield immortality. It has no other use, which is why it isn't used in Potions - and why people who forage amongst unicorn carcasses seemingly leave the blood alone. The blood is useless if the unicorn is alive or has died naturally.

"You have slain something pure and defenceless" - as Firenze describes it it's like the exchange of one life for another, an innocent creature's for a greedy human's. There has to be death, and intentional death, for it to work.

Of course, Firenze doesn't actually say "The blood of a slain unicorn will keep you alive...". He says, "The blood of a unicorn will keep you alive". Hence the question is a good one, and the slither of ambiguity about the rules on unicorn blood exists.

However, Firenze is only ever talking about slain unicorns in his speech. It would be weird if he were start talking about unicorns in general halfway through. I think we can assume that in order to achieve immortality by drinking unicorn blood you have to have killed the unicorn yourself, to slay it "to save yourself". Therefore, someone drinking the blood of a healthy, living unicorn would not receive the curse that Firenze describes. Neither would they receive immortality. They would simply be drinking unicorn blood for its own sake, which (unless it's your aperitif of choice) is a rather random and futile thing to do.

  • By the way, the extract from Fantastic Beasts and Where to Find Them doesn't address this point at all. Jan 15, 2018 at 14:24
  • 3
    I think that's a solid answer - and, especially interesting when one consider a horcrux - another magical tactic to extend / retain life that requires a death. One could almost see the unicorn conversation as a small bit of foreshadowing / foundation laying.
    – NKCampbell
    Jan 15, 2018 at 14:34
  • 1
    @TheDarkLord not surprised it wasn't included. newt is a gentle soul and probably wanted to keep his book family friendly. ..
    – user68762
    Jan 15, 2018 at 15:10
  • It should be noted that it is likely to be impossible to get blood from a live unicorn, because I think Hagrid said they are very difficult to catch. Same for getting blood from a tame unicorn. Most likely they cannot be domesticated.
    – user13267
    Jan 15, 2018 at 15:59
  • 3
    @user13267 As NK Campbell's question points out, they do capture one for study in a Care for Magical Creatures class in year four. That unicorn may not have been domesticated as such but it was captured and restrained. Jan 15, 2018 at 16:03

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.