If you’re at all familiar with the series, then you know that the wizarding world of Harry Potteris filled with A LOT of things that can harm a human. Vicious magical beasts, spells that can kill you on the spot, and potions that, if brewed incorrectly, can be fatal.

Obviously, Polyjuice Potion falls into that last category—a brew that you wouldn’t want to go wrong.

But if it did, what would happen?

In this article, we’ll cover all that you need to know about this somewhat fickle potion, including the risks if something were to go terribly wrong.

Everything You Need to Know About Polyjuice Potion

What Is Polyjuice Potion?

Polyjuice Potion is a complex concoction that’s known to be especially difficult and time-consuming to brew. Those new to potion making would be ill-advised to try their hand at making this particular magical mixture, as it generally requires great skill and experience to get it right.

The purpose of Polyjuice Potion is to transform one witch or wizard into that of another; thereby taking on the appearance of someone other than themselves.

What does Polyjuice Potion look like?

When the brew is almost complete, Polyjuice Potion basically looks like thick mud. When the potion takes on this appearance, the final ingredient is added, which is a piece of the soon-to-be-impersonated individual. This can be anything from a strand of the person’s hair to one of their toenail clippings.

With the final addition of the person’s what-have-you, the potion typically changes in colour to align with the “essence” of that individual.

What goes into Polyjuice Potion?

Aside from the piece of the person you want to look like, there are a handful of other rather rare ingredients. See below for a full list!

INGREDIENTS FOR POLYJUICE POTION

“Lacewing flies (the first part of the name suggested an intertwining or binding together of two identities); leeches (to suck the essence out of one and into the other); horn of a Bicorn (the idea of duality); knotgrass (another hint of being tied to another person); fluxweed (the mutability of the body as it changed into another) and Boomslang skin (a shedded outer body and a new inner).”

J.K. Rowling

When and How Polyjuice Potion Is Used in Harry Potter

Despite the warning that only experienced witches and wizards should take on making a batch of Polyjuice, Harry and his friends brew an awful lot of this stuff over the years.

Below is a run down of when and how this tricky potion was used by characters in the series.

The Chamber of Secrets: Hermione’s Mishap

Hermione brewed Polyjuice for the first time as a 12-year-old second-year—and did so incredibly well for a witch her age! With one minor exception. She kind of turned into a cat, slash human.

While she certainly managed to assist Ron and Harry in turning into Crabbe and Goyle, Hermione herself was not so fortunate in her attempt to transform into Millicent Bulstrode. But more on that in a minute!

The Goblet of Fire: Barty Crouch Junior’s Long Con

After getting to know—and dare I say, love?—Professor Alastor “Mad-Eye” Moody throughout Harry’s fourth year at Hogwarts, it’s revealed that this wizard wasn’t the man we thought he was. Literally.

For an entire school year, Death Eater Barty Crouch Junior had been sipping Polyjuice Potion and impersonating Professor Moody in order to manipulate Harry Potter and the Triwizard Tournament.

The Deathly Hallows: Everyone, All the Time

In what would have been Harry, Ron and Hermione’s final year at Hogwarts, the Golden Trio drink A LOT of Polyjuice.

It starts with Harry’s allies all taking the potion to resemble Harry himself in order to get him safely to the Weasleys’ family home at The Burrow. Just days later, Harry then pretends to be “Barney Weasley”—a fictional relative of the family—so that he can attend Bill and Fleur’s wedding incognito.

And who could forget the time that Hermione transformed into the likeness of Bellatrix Lestrange in order to break into her vault at Gringotts? Or when Harry, Ron and Hermione broke into the Ministry of Magic by impersonating Ministry employees?

And yet, with all these examples, there seems to be little danger involved in consuming this rather complex potion. That is, with the exception of Hermione and her—err—little mishap in her second year at school.

So, what CAN happen if this complicated potion is brewed or taken incorrectly?

The Risks of Taking Polyjuice Potion

Like any powerful and effective magic, Polyjuice Potion comes with its own risks. From what we know, the biggest danger with this concoction seems to be drinking it if brewed with a non-human body part.

In the case of Hermione in The Chamber of Secrets, she accidentally made the potion using cat hair. As a result, she became half-cat, half-human and needed to be treated by Madam Pomfrey, the Hogwarts’ school nurse.

If Hermione had not been treated, she would have remained in this state PERMANENTLY.

What Else Could Go Wrong?

While the books don’t delve into all the possible dangers, due to its complex nature, there are likely many other ways Polyjuice could cause harm.

For example, using the wrong amount of an ingredient might result in a distorted or incomplete transformation. Maybe even death.

Polyjuice also only lasts so long. It’s possible that if a witch or wizard attempted to tweak this outcome, there may be lasting consequences.

But, as I mentioned, these are merely speculations. And the only canonical event that we have to draw any conclusion from is when Hermione drank the feline-hair potion.

So, if Polyjuice goes wrong?

Basically, you become a GIANT CAT.