Welcome to Potions 401!

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Lesson 6) Who Do You Think You Are? (The Polyjuice Potion)

Upon arriving at the classroom, you notice that an empty mug is placed on your desk. You look around, confusedly, and notice that all of the other desks are topped by an empty mug as well. Many of your classmates seem to share your confusion, and try inspecting the mug more closely.

With a flick of the wand, Professor Draekon fills all mugs with hot chocolate. You can feel a faint smell of raspberries coming from the liquid, indicating the syrup that has been mixed into the drink.

“I know I have twisted your expectations last Midterm, so consider this your just rewards”, Professor Draekon stated nonchalantly. "Since today we will not brew any potions, I decided to give you all a reprieve of my usual rules, and let you drink something in my class. Just this once", the man states forcefully, clearly giving you the idea that breaking this rule in the future would result in swift punishment.

"I hope this doesn’t intimidate anyone, but we’ll be getting a lot more heavily into theory and practical knowledge beyond a bunch of random ingredients and basic body functions as we move into future years. We’ve touched on a good deal of simpler traditional theory in past lessons, but especially as you get into Years Six and Seven, we’ll be discussing contemporary experimental potions, their attributes, and their creation."

Wonderful, I’m glad you survived the midterm. We’ll begin where I promised, taking a slightly deeper look at a few of the magical ingredients used in the last lesson, as I think you may not have had previous experience with them.

Firstly, an ingredient I think you know fairly well, fairy wings. You may have noticed that fairy wings are used in a number of beautifying potions. If you are a student of Care of Magical Creatures, you discussed this briefly last year: fairy wings are often listed as a secondary ingredient in beauty and physical potions because, while they do not have impacts on a person’s physique, they do impact the chemicals that a person emits to influence the people around them. Fairy wings increase the impact of basic pheromones of an individual on a grand scale. Pheromones are chemicals that encourage or bring about social response from members of the same species. Depending on the hormones involved, this can bring about aggressive or violent responses, fear or attraction depending on the pheromone.

Fairy wings impact what is known as the sex pheromone (also with some small properties influencing a calming pheromone). These chemicals are not, of course, strong enough to make someone hallucinate their ideal person physically, but when other humans inhale these pheromones, studies indicate that it does tend to make people feel “warmer” and generally more positive towards those they see. Fairy wings are sometimes used in affability and charisma potions as well.

Sex pheromones also have other effects. For example, androstenol, the pheromone secreted by women, can impact the monthly biological cycles of other women around them - I’m sure many of you have noticed this with your classmates or other people with whom you spend time regularly.

Mind you, manipulation of pheromones is not a strictly magical phenomenon. While studies show inconclusive evidence as to the actual effectiveness of these methods (most indicate they are mostly useless, in fact), there are many Muggle perfumes that utilize pheromones and claim to make the person irresistible to their desired romantic target. Pheromone level can also be naturally raised through simple means, such as regular exercise and proper sleep.

A secondary characteristic of fairy wings when exposed to magical catalysts is that they cause hallucinations for those who consume them, albeit mild in the form of beautification potions. Indeed, in Russian magical tradition there is a beverage known as feya-pivo that is concentrated fairy wings brewed alone in water. Sugar is then added, and it’s allowed to mature for two weeks. This beverage is considered similar to the Muggle alcoholic beverage absinthe. In beautifying potions, however, the effect is much less pronounced, and instead tends to boost the consumer’s impression of him or herself. This increased confidence also increases how attractive they seem to others, since general self-comfort can often be perceived as attractive.

The first entirely unfamiliar ingredient from the last lesson was the inclusion of the gum Gomas barbadensis (or “Barbados Gum”). This substance is a mixture of the saps of the following magical trees:

  • Adansonia femmarina (commonly the Mermaid’s Tree)
  • Ficus cantafolia (commonly the Broadleaf fig)

These trees are natives to Barbados, and in fact blend in perfectly in appearance to their non-magical counterparts, the baobab tree and the wild Banyan respectively. Although the individual saps have been used in potions dating back before the 16th century, when only Amerindian populations inhabited the islands, it was not until 1732 that a Dutch Brazilian wizard named Cauã Matheus Segher, a rather vain wizard who was rigorous in his skin and hair treatments, thought to combine the two saps when he made the impulsive decision to go brunette and did not have previous (typically less permanent) potions at hand. While it gained some popularity in the Americas following Segher’s experimentation with the mixture, Gomas barbadensis did not become a common ingredient in Europe until the 20th century.

When used in potions, Gomas barbadensis has been found to subtly alter the chemical composition of the hair particles in order to encourage a change in eumelanin and pheomelanin (which is, as we studied before, the substance that provides hair with its distinctive red tint). With regards to eumelanin, Gomas barbadensis can affect both the amount of brown eumelanin (to make hair darker or lighter), as well as black eumelanin (small amounts without other pigments cause grey hair). It is also used in some skin tinting potions and magical self-tanners.


The final brand new ingredient, Indigofera peculia, is a magical plant also derived from tropical regions, including Barbados. The genus Indigofera consists of several species of plant that can be used to create indigo dye. Indigo is a color most closely associated with a tone halfway between blue and violet, and is also said to be representative of the third eye chakra. However, as an ingredient in potions, Indigofera peculia provides a permanent darkening feature, in which it increases the melanin or other dark pigment on the body or even in inanimate objects.

One notable quality of this plant is the fact that it can only be observed by the light of the full moon. While the plant is still a corporeal entity during daylight and other stages of the moon, the means by which it reflects and refracts light causes it to be essentially undetectable using the basic five senses. However, the particular quality of moonlight present during the full moon causes a specific refraction on the leaves of the Indigofera peculia, allowing it to be seen to the naked eye. There are many theories as to why this plant behaves in this way, but most explanations are simply hypothetical now. It is interesting to note that some detecting spells currently in the research process have had some luck in finding the plant without the presence of the full moon. However, many researchers feel that the energetic vibrations of the plant impact visual perception - and possibly other senses as well as magic - in some way not yet understood.

More broadly speaking, when used in a Tinting Tincture, one can expect Indigofera peculia to directly impact the color exhibited on a light to dark scale. Not enough research has yet been put into examining the plant as found “naturally” (visually) in contrast to its detection by other means to assert the difference in potency. However, the most basic research has indicated that it has much stronger effects if gathered during the time when it can be viewed by the naked magical eye.

Polyjuice Potion: A History


Given the nature of its use over the last few decades, Polyjuice Potion has become an oft-admired brew for young witches and wizards as they arrive at Hogwarts with dreams of the famous Boy Who Lived. While of course we will not be going over Moste Potente Potions this year, we will be learning a little more about the history and process of the Polyjuice Potion.

Phineas Bourne was a British potioneer of the early to mid-19th century. We will cover his life and works in depth in Year Six, when we cover “offensive” and “defensive” potioneering. However, for Year Four, suffice to say that he was very interested in potions that could unwit, deceive and disarm potential opponents. While Bourne did not research and uncover his own unique potions, instead he studied, collected and perfected potions of previous magical generations in order to create a compendium of the most dangerous potions of his era.

The Polyjuice Potion, for example, while named by Bourne, was a potion created in the later 18th century by a witch named Abigail Crayne. Crayne came from a British magical family who moved to the New World and settled in upstate New York prior to the Revolutionary War. Raised in the colonies, Abigail only feigned allegiance to the Crown when war broke out. Her parents’ true fidelity helped her cover, but she soon joined the Culper Spy Ring, never alerting them to her true magical inclinations. Born with a knack for transfiguration - though not a metamorphmagus - Crayne found herself wishing she could more easily complete physical transformations to gain access to important conversations between British soldiers and even officials. Stealing some of her father’s early notes, he being himself an experimental potioneer working on helping the English army, Crayne used her own knowledge of properties of transfiguration to modify some early stage recipes he was constructing, eventually coming up with the Polyjuice Potion.

Once she perfected its use, albeit within a limited timeframe, Crayne utilized the potion in order to more effectively gather intelligence for her brethren in the spy ring. Using her access to mid-level British officers, she could easily collect hair, fingernails, and other genetic material to use in the potion. While her work caused a good deal of confusion among the British ranks, neither the soldiers nor her family guessed the brand new potion she had concocted in order to more efficiently get information.

While no one in the Culper gang ever learned of Crayne’s identity, she did share the recipe with her only son, Francis Irving, who passed it down over generations until it eventually found its way into Phineas Bourne’s book with slight improvements and modifications to the original recipe.

So what’s the difference between Polyjuice Potion and transfigurative spells that change a person’s appearance? Similarly to spells, Polyjuice Potion only lasts for a limited duration, between ten minutes and twelve hours - even for the most skilled brewer - if the witch or wizard doesn’t consume another dose before the effects fade. However, there are two key differences between using the potion and simply transfiguring oneself:

  1. The potion enables one to precisely emulate the attributes of another. While, as you might imagine, transfiguration requires accounting for all physical aspects of a person in order to properly emulate them trait by trait, one simply needs the genetic material of the subject to change into them with the Polyjuice Potion.
  2. Once the potion is imbibed, the witch or wizard does not have to expend any additional energy in order to keep the spell “active.” However, this also means that he or she does not have any control over when the spell extinguishes itself and he or she reverts to the original form.

The Polyjuice Potion cannot transform someone into an original or “non-existent” being. Instead, it can only take similar human genetic material and transcribe (or copy) it over their form for a short, limited time. It is interesting to note, however, that one can use cells from deceased persons for a period of time after their demise. As long as the cells have not begun to decay and disintegrate, one can transform into another human as they looked at the time of their death. Thus, as you can imagine, a black market trade has emerged in the magical world that peddles the genetic material of recently deceased Muggles. As they are most often unknown in the magical world, Muggle hair and nails provide a relatively safe passage through the magical world when one wants to change identity to travel.

How does the Polyjuice Potion work? (WARNING: We are about to tread back into Year One theoretical territory, where we briefly covered the concept of DNA and genetic material! I’ll try not to be too obtuse: we’ll save more intensive theoretical talk for later years.)

Well, those who keep abreast of Muggle scientific innovations will have read a fascinating article recently in which scientists at Tufts University in the United States were able to interrupt cellular communication within flatworms after cutting the heads off in order to “trick” the original host into thinking it was another species of flatworm [1]. The heads and brain mechanisms that grew back resembled those of similar species that were “programmed” or triggered in the cellular communication of the original organism. Thus, while the actual species of the flatworm did not change, the physical characteristics that regenerated part closely resembled the physical traits of a whole different species.

Of course the Polyjuice Potion doesn’t work exactly like this: obviously you are not cutting apart limbs or permanently changing genetic messaging. However, magical theoretical researchers have compared what they’ve observed of the short-term impacts on the body to this new Muggle discovery. The potion temporarily shifts vital genetic information, such as hair color, skin pigmentation and eye color, in order to resemble another being. Now, certain additional characteristics, such as specific fat distribution, body size, and markings on the body (freckles, pimples and similar) are yet unexplained by researchers. As these traits cannot be found in the genetic material - although a proclivity towards developing freckles, becoming overweight and similar traits may exist in one’s genetic makeup - it is thought that the potion has some additional qualities that make it more specific in replication than simply copying genetics and DNA.

Studies have shown that when a witch or wizard imbibes the potion, the user undertakes a rather unpleasant temporary transformation of DNA. When taken too frequently, this can prove dangerous, as the DNA of the individual may become permanently corrupted, and regression to one’s original form can be incomplete.

This negative side effect happens at an accelerated rate when the genetic material of a different species is used, particularly when brewed by an unskilled witch or wizard. This was best exemplified by the use of cat fur by famous witch Hermione Granger during her second year at Hogwarts. Hermione’s body was unable to properly replicate another species’ DNA perfectly, creating a rather morbid hybrid. Her body was unable, even after an hour, to revert to its own functioning because of the disruption, and she was forced to go to the hospital wing for intensive care.

While this may sound amusing, it is no small matter. Improper return to one’s original form, especially when the DNA of another creature is involved, has led to serious organ shutdown, including heart attack and stroke. The Polyjuice Potion should never be brewed by an amateur potioneer, and this lesson is intended to simply be a theoretical example of the potion and its creation.

Now, for an overview of the ingredients of the Polyjuice Potion. Please note you will not have access to the full brewing process until your most advanced years, but you will find the potion in the library at that point, should you wish to examine its complexities. For now, I will give an overview of ingredients and correlated notes.

Polyjuice Potion (Abridged) [2]

Estimated Brew Time:
2 days and 18 hours

Total Brew Time:
1 month, 2 days and 18 hours

12 lacewing flies1
28 g Antimony1
4 leeches2
5.25 g fluxweed (picked on a full moon)1
12 g Sal ammoniac2
60 g knotgrass2
15 g powdered horn of bicorn1
30 g shredded skin of boomslang1
5 g saltpeter2
5 g mercury2
5 g Pulvis Martis2 [3]
Genetic material of the one you wish to become1

Ingredient Notes

Do note that, if the fluxweed used in the potion is not gathered on the full moon, the potion is not useless, but will lead to severe stomach cramps with the possibility of stomach ulcers and bleeding of the stomach lining.

If you’d like more than this very brief glimpse of Polyjuice Potion, please make sure you keep with Potions until Year Seven, when you will be able to review sections of Moste Potente Potions in the library and in conjunction with your studies as a more advanced potioneer.

And that's about it for today. I hope this slightly more complicated view of Polyjuice Potion wasn’t too convoluted in terms of its theory and mechanisms: I trust you all have the experience thus far to be able to understand it. If not, my office is always open.

I look forward to seeing you all next week when we will begin to tackle the less-immediately obvious positive attributes of the body - namely, wit and intelligence.


Original lesson written by Professor Lucrezia Batyaeva
Image credits here, here and here


[1] It should be noted that flatworms are one of the best types of regenerators. They are able to rebuild almost any part of their body that is lost.

[2] Permission may be obtained to view Moste Potente Potions in full when you reach Year 7.

[3] Pulvis Martis is a magical ingredient made of charged iron filings. As you may have learned if you take Alchemy with Professor Rosenquist, iron filings would not have many of the properties of solid iron. Thus, in order to make them usable as magical ingredients, alchemists must enchant them to restore some of the properties of confidence. The confidence instilled by enchanted iron filings gives the taker one last “boost” to be able to complete the perceived physical transformation. It should be noted that adding too much Pulvis Martis to a potion may make it terribly volatile and unstable.


In Year Four of Potions, students will focus on Physical Modifying Potions. This will include beauty, blemish removal, and even the famous Polyjuice Potion. Every lesson will include a lab exercise that will teach the student the relationship between potions and their impact on the physical body.
Course Prerequisites:
  • PTNS-301

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