Polyjuice Potion

• Type: Potion (Transfiguration)
• Known Brewers/Users: Hermione Granger, Barty Crouch Jr., members of the Order of the Phoenix, Death Eaters
• Source: Moste Potente Potions

The Polyjuice Potion is a highly complex and powerful potion that allows the drinker to assume the physical appearance of another person. The brewing process is difficult and takes approximately one month to complete. Before the final, personal ingredient is added, the potion is thick and dark, resembling mud, and bubbles slowly. After a piece of the person to be imitated (most often a hair) is added, the potion changes in color, taste, and consistency. For instance, when Harry Potter and Ron Weasley impersonated Gregory Goyle and Vincent Crabbe, the potions turned a “nasty, khaki” and a “sickly-yellow” color, respectively. The taste is universally unpleasant, described by Harry as being like “overcooked cabbage.”

The primary effect of the Polyjuice Potion is to temporarily transform a human into a physical duplicate of another human. The transformation is extensive, altering the drinker's build, skin, hair, and even their voice to match the target. The process of transforming is described as painful, with the drinker feeling as if their skin is bubbling like hot wax. The effects of a single dose last for precisely one hour. To maintain the disguise for longer periods, the drinker must consume fresh doses regularly, as Barty Crouch Jr. did for nearly an entire school year. Ingredients:

• Lacewing flies (stewed for 21 days)
• Leeches
• Powdered horn of a Bicorn
• Knotgrass
• Fluxweed (picked at a full moon)
• Shredded skin of a Boomslang
• A piece of the person one wishes to become (e.g., a hair)

Limitations:

• The potion is intended for human transfiguration only. It cannot be used for transforming into an animal or a non-human creature. When Hermione Granger accidentally used a cat hair instead of a human one, she developed feline features such as a furry face, yellow eyes, and a tail, a transformation that was difficult to reverse and required a stay in the Hospital Wing.
• The potion does not change the drinker's mind, personality, or knowledge. The user must act the part of the person they are impersonating.
• It does not duplicate possessions such as clothes or wands; the drinker must acquire these separately.

The Polyjuice Potion plays a critical role in several key events throughout the series, primarily in plots involving deception and infiltration.

• Second Year at Hogwarts: Hermione Granger successfully brews the potion in Moaning Myrtle's bathroom. Harry Potter and Ron Weasley use it to transform into Gregory Goyle and Vincent Crabbe to question Draco Malfoy about the Chamber of Secrets. This event also led to Hermione's partial transformation into a cat.
• The Triwizard Tournament: Barty Crouch Jr., a loyal Death Eater, uses a constant supply of Polyjuice Potion to impersonate the Auror Alastor Moody for an entire school year. This deception allowed him to manipulate the Triwizard Tournament from within Hogwarts, ensuring Harry Potter would be transported to Little Hangleton for the rebirthing ceremony of Lord Voldemort.
• Draco Malfoy's Secret Mission: During their sixth year, Crabbe and Goyle use the potion to disguise themselves as first-year girls to act as lookouts for Draco Malfoy while he worked on repairing the Vanishing Cabinet in the Room of Requirement.
• The Second Wizarding War: The potion saw extensive use by the Order of the Phoenix and the trio.
  • Battle of the Seven Potters: Six members of the Order (Hermione Granger, Ron Weasley, Fred Weasley, George Weasley, Fleur Delacour, and Mundungus Fletcher) took Polyjuice Potion containing Harry Potter's hair to act as decoys, protecting the real Harry during his escape from Number Four, Privet Drive.
  • Infiltration of the Ministry of Magic: Harry, Ron, and Hermione used the potion to disguise themselves as Ministry employees (Albert Runcorn, Reginald Cattermole, and Mafalda Hopkirk, respectively) to infiltrate the Ministry and steal Salazar Slytherin's Locket from Dolores Umbridge.
  • The Gringotts Heist: Hermione used a hair from Bellatrix Lestrange's robes to transform into the dark witch to gain access to the Lestrange Vault at Gringotts.

• According to Pottermore, brewing Polyjuice Potion is incredibly difficult and is a skill taught only at N.E.W.T.-level Potions classes at Hogwarts. (Pottermore)
• The name is a combination of the Greek prefix poly-, meaning “many,” and “juice,” literally meaning “many-juice,” a reference to its ability to give the drinker many faces. (Pottermore)
• In the film adaptations, the transformation sequence is depicted with dramatic visual effects, showing the drinker's body contorting and bubbling as it reshapes itself. (film)