For most of us school had its hazards, but fairly innocuous ones like knocking over a Bunsen burner or gluing parts of our fifth-year art project to our blazer.
The potion class storeroom from the Chamber of Secrets

At Hogwarts the teachers had to warn against rather more dangerous perils than leaning too far back on a chair. Bezoars at the ready, just in case anyone swallows anything they shouldn’t...

Polyjuice Potion

Polyjuice Potion was a thick, powerful tonic with serious consequences if you mixed it wrong. Harry, Hermione and Ron first tasted some when they went undercover as Draco Malfoy’s sidekicks. Members of the Order of the Phoenix glugged it down to disguise themselves as Harry Potters, and it also helped Harry, Hermione and Ron break into the Ministry of Magic.

But if it could be used for noble reasons, it could be used for sinister ones, like when Barty Crouch Jr used the elixir to escape Azkaban. Just be careful to pluck the right hair from the person you wanted to become: as Hermione discovered, a stray cat hair could cause an unwelcome transformation...

Mandrake

One of the greatest plants in Herbology, the Mandrake was a crucial ingredient in most antidote treatments. The secret to cultivating a fully-grown Mandrake (should you need it) was earmuffs. A Mandrake cry was fatal to anyone who heard it – which was precisely why Professor Sprout only let students handle seedlings.

A screaming mandrake seedling in a Herbology Lesson

Veritaserum

A truth potion is a good thing, right? Well, at Hogwarts, Harry discovered that it was good to keep a few truths to yourself. At one point, Professor Snape gleefully threatened to slip a few drops of Veritaserum into Harry’s evening pumpkin juice. Then, when Professor Umbridge wanted to interrogate Harry, he claimed to be clean out of the potion and declared that any alternatives would be fatal. It was one of those precious moments you weren’t sure whose side Snape was on.

Amortentia

If there’s one thing stronger than young love, it’s this love potion. Think of the incorrigible Romilda Vane and then picture Ron Weasley’s dazed face when he ate the spiked chocolates she meant for Harry. Amortentia was the most potent love potion in the world and no one was immune. Even know-it-all Hermione got an attack of blushing embarrassment when she caught a whiff of it during Potions class.

Draught of Living Death

If you were listening in first year Potions, you’d know that mixing asphodel and infusion of wormwood will produce a sleeping potion so powerful you’d snooze through the Battle of Hogwarts. Even when following instructions in Advanced Potion-Making by Libatius Borage, few could master a good brew – except Severus Snape, of course.

Snape teaching potions from the Philosopher's Stone

Venomous Tentacula

The clue is in the name – this isn’t the kind of plant you’d give your aunt for her conservatory. How many pieces of foliage to do you know that actually go through a teething phase? Luckily during Herbology lessons it was deemed acceptable to swear loudly if attacked by one of these spiky, dark red plants. And in the right hands (like those of star Herbologist Neville Longbottom), they were the perfect weapons for tackling a Death Eater.

Snargaluff

If you happen to have a copy of Flesh-Eating Trees of the World on your bookcase, you’ll know all about the Snargaluff. To juice it you’ll need a sharp knife and the strength to fight back when its stump goes for your throat. Then it’s just a case of plucking out a pod, bursting it open and pouring yourself a bowlful of pale green tubers that wriggle like worms. Don’t worry, Snargaluff juice won’t be coming to a breakfast table near you anytime soon.

Shrinking Solution

Preparing a potion incorrectly can produce results far worse than a simple ‘fail’. Remember when Snape took great delight risking Neville’s toad in putting Longbottom’s Shrinking Solution to the test? If it had worked, Trevor the toad would have become a tadpole. If it hadn’t, the beloved amphibian would have been poisoned. But thanks to Hermione’s discreet intervention, Trevor lived to ‘ribbet’ another day.

Pepperup Potion

Not all potions at Hogwarts were perilous, of course; just potentially very embarrassing in a classroom. Some excellent-sounding mixtures got just the briefest mention – Severus Snape threatening Harry Potter with Babbling Beverage, for example – and others were used for medicinal purposes. Feeling peaky with an October chill coming on? Madam Pomfrey, the matron, could sort you out with a flagon of her Pepperup Potion. But don’t be surprised, however, when you’re left smoking at the ears for several hours afterwards...

Ageing Potion

Funny really. While adults spend a fortune to look younger, teenagers spend years trying to be more grown-up than they really are. When Fred and George discovered they were too young to enter their names for the Triwizard Tournament, they decided that a few drops of Ageing Potion would do the trick. It wasn’t powerful enough to trick Dumbledore’s Age Line, though. That’s when the Weasley twins were propelled across the room, sprouting long white beards that had to be magically removed by Madam Pomfrey.

The Goblet of Fire rejects the Weasley twins names.
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