History Main / KryptoniteFactor

[[caption-width-right:350:"Hey Superman, check out this awesome glowing rock I found! ...Supes? You okay?"]]

* In ''WesternAnimation/JusticeLeagueCrisisOnTwoEarths'', Superman's EvilDoppelganger Ultraman is weak to blue kryptonite rather than green (like Bizarro). Ultraman [[GenreSavvy wised up to this trope being used against him]] and at some point went out of his way to destroy every sample of blue kryptonite on the planet; the alternate Lex Luthor counters this by bringing a sample from the mainstream Earth with him.

* ''WesternAnimation/SupermanDoomsday'' contains an almost amusing example in that even ''Superman'' needed Kryptonite to defeat his clone with identical powers. Admittedly, the real Superman isn't quite at full strength at this point.
--> '''Superman''': You have all my strengths... and weaknesses.

* Lampooned in-character in ''Film/TheAmazingSpiderMan'', when Spider-Man responds to a crook pulling a knife by [[LargeHam melodramatically pretending to collapse]] and gasping "You've discovered my weakness... small knives!".
* ''Franchise/DCExtendedUniverse'':
** ''Film/ManOfSteel'':
*** Exposure to Krypton's native environmental conditions weaken and at first even incapacitate Superman.
*** Zod's Kryptonians similarly initially lose control of their powers and pass out while trying to adapt to Earth's native atmosphere.
** ''Film/BatmanVSupermanDawnOfJustice'' has Kryptonite discovered among the wreckage of the [[DoomsdayDevice Kryptonian World Engine]] near India after the events of ''Man of Steel''. It's explained as a radioactive isotope that actively harms Kryptonian cells. Before a large chunk is found in the Indean Ocean, the most they could find was only good for surgical tools. [[AdaptationalWimp In contrast to most portrayals, a small amount has no effect just in proximity.]] [[spoiler:Batman develops Kryptonite-laced gas grenades at his best bet at subduing Superman, with a spear as a FinishingMove.]] This also applies to [[spoiler:Doomsday, who is Kryptonian in origin and just as vulnerable to Kryptonite]].

* ''Film/XMenApocalypse'': Nightcrawler's teleportation power is blocked by electrical fields. They also interfere with Jean Grey's telekinesis and telepathy.

* ''Series/LoisAndClark'', setting the tone for most [[Series/{{Smallville}} adaptations]] [[Series/Supergirl2015 after]] it, has red kryptonite affect him mentally instead of the comicverse rules of random one-off effects. Just how dark-side it makes a Kryptonian go depends on the tone of the adaptation, but one thing remains the same: under Red K, Kryptonians are dicks. However, this series also had Red K used to power devices that ''would'' affect him in different ways. You get dickishness out of merely putting a chunk of it near him, though.

* ''Series/{{Smallville}}'' made use of this so often it could get to ridiculous extremes...though, it ''was'' a JustifiedTrope in-universe: Clark's shuttle arrived alongside a massive Kryptonite meteor shower, and Kryptonite became a super-useful {{Unobtainium}} that provided a MetaOrigin for most villains, with the Kryptonite Factor weakness merely an unknown side-effect. Kryptonite radiation induced metahuman mutations and until season 4, was seemingly the cause of ''every'' superhuman (ergo, every super-powered threat Clark faced was also armed with his one weakness). It was also a great power-source and wonder-drug for any crazy scheme a villain could have, as well as seemingly able to do ''anything'', including provide ''ink for counterfeit money''.
** Outside of weekly villains, Kryptonite was used as a means to intervene with Clark's relationship with Lana Lang (his original love interest). Yes, Kryptonite wasn't ''just'' used to empower villains and weaken his superpowers, but also ''cock block'' him, too. Lana had a necklace with a piece of Kryptonite on it, and the effect of it made everyone assume Clark just had crush-induced nausea. Later, Lana became a ManOfKryptonite after absorbing a large dose of it to save everyone, forcing the two to separate and never see each other again.
** As for Blue Kryptonite as Bizarro's weakness, Blue K was introduced in the series in a storyline unrelated to Bizarro - it was a total off-switch for Kryptonian powers but otherwise harmless. However, when Bizarro appeared, he was no misguided, well-intentioned dimwit - he was a Phantom Zone criminal who could possess others, causing PossessionBurnout, but ended up creating a new, duplicated body when he tried to possess Clark. He was Clark's opposite in every way, including weaknesses - he was hurt by sunlight and fueled by Kryptonite. This means that Blue K, instead of leaving him no power, gave him the opposite - infinite power, more than he could contain, blowing him to smithereens.

* ''Series/Supergirl2015'':
** The DEO reveal early on they have access to actual Kryptonite based tech, and that general knowledge of it as a Kryptonian weakness is limited. They use it to subdue ComicBook/{{Supergirl}}, and J'onn uses a Kryptonite knife against Astra. In [[Recap/Supergirl2015S1E12Bizarro "Bizarro"]], Bizarrogirl is hurt with blue Kryptonite. Kara can also be hurt by other alien materials. Apparently, Superman and J'onn had a falling out because DEO has been stockpiling kryptonite for use against evil Kryptonians. They finally reconcile, after J'onn hands the stockpile over to Superman.
** L-Corp has some synthetic Kryptonite, but it's very unstable and has a tendency to blow up. Lena Luthor and Supergirl have a falling out over this, as Supergirl is absolutely insistent that the Kryptonite be turned over to her, which Lena is not happy about. Supergirl says being exposed to Kryptonite is like being tortured, but Lena says she's just being a hypocrite who doesn't want to be vulnerable. Supergirl later apologizes for her actions, saying that Lena was right, but she feels like she ''can't'' be vulnerable because she has the weight of the world on her shoulders.
** Red sunlight, while not actively harmful, quickly renders Kryptonians as powerless as they were on Krypton. It's one of the DEO's primary weapons against Kryptonians. Flashbacks show that shortly before the start of the series, Lex (who wasn't able to get his hands on Kryptonite) somehow managed to turn Earth's sun red. When Lena insisted that humans can't survive with a red sun, Lex just retorted "neither can Superman."
* In ''Series/SupermanAndLois'', Superman has the usual weakness to green Kryptonite and red sun. The DOD has developed a number of Kryptonite-based weapons that come useful when they end up having to deal with evil Kryptonians. Bizarro, being an inverse of Superman, is strengthened by the red sun and green Kryptonite but is weakened by the yellow sun and X-Kryptonite.

* ''[[Series/WonderWoman1975 Wonder Woman]]'':
** Initially, Wonder Woman would lose her superhuman strength if her magic belt was removed from her uniform. Similarly, she possessed no resistance to chloroform, which conveniently made its way into a number of Season 1 episodes. When the show was moved to the 1970s, the former weakness was addressed only once (and only then when she willingly removed her belt, lasso, and bracelets to assure an enemy that she did not wish to fight him), and the chloroform was used far less often.
** There's another, less obvious weakness - Diana Prince needs enough freedom of movement to spin to turn into Wonder Woman. No villains ''deliberately'' exploited this (since very few knew about her secret identity in the first place), but several accidentally used it when they handcuffed Diana to a support beam or something similar.

* ''WebAnimation/DCSuperHeroGirls'': The green stuff is around, and worse, Red Kryptonite has the same mental effects it does in most adaptations, but with one big difference: ''humans go dark side too.'' [[HatePlague Uh-oh]]. Lena Luthor created ''living'' Kryptonite creatures known as Kryptomites, AdorableEvilMinions who still keep their harmful properties.

* ''WesternAnimation/BatmanTheBraveAndTheBold'':
** When Batman [[spoiler:received powers on the planet Zur-En-Arrh, the supervillain Rothul quickly figures out the new Superman-like Batman's weakness: Quartz]].
** Superman fell under the influence of Red Kryptonite. As mentioned above, in the comics it has a different one-off effect every time Superman is exposed to it, while in television it usually affects him mentally. This show has it both ways: Red K has random effects, and ''this'' time its effect is gonna be SuperDickery!

* ''Franchise/DCAnimatedUniverse'':
** Interestingly, in ''WesternAnimation/SupermanTheAnimatedSeries'', it was originally planned that ComicBook/{{Supergirl}}, being in this iteration not from Krypton, but rather the sister-planet of Argos, would not have a weakness to Kryptonite. This is demonstrated in the "Superman Adventures" comic based on the series. By the time of ''WesternAnimation/JusticeLeague Unlimited'', though, the weakness was firmly in place.
** The ''WesternAnimation/JusticeLeague'' cartoon downplayed or ignored the Kryptonite Factor of every character ''except'' Superman. ComicBook/GreenLantern's vulnerability to yellow was never actually mentioned (though occasionally, if you watch closely, you'll see yellow stuff getting through his force barricades). [[ComicBook/MartianManhunter J'onn J'onnz]] had no particular vulnerability or [[WhyDidItHaveToBeSnakes phobia]] regarding fire (though he had a bad case of TheWorfEffect in the first season, and he would occasionally struggle in situations where there was a lot of fire). {{ComicBook/Aquaman}} never seemed overly discomforted by being out of water for extended periods. Characters/{{Wonder Woman|TheCharacter}}... well, she'd lost most of her Kryptonite Factors by the time the series started anyway. Hawkgirl eventually ''gained'' a Kryptonite Factor that was more emotional than physical and ended up resolved by series end anyway. [[Characters/DCAUTheFlash The Flash]] almost never used his powers to their full extent (not unlike Superman), with the idea that he never really pushed himself to excel...and when he did, he was given a convenient excuse not to again. [[Characters/DCAUBatman Batman]]'s "Kryptonite Factor" -- that he was [[BadassNormal a perfectly mortal human]] -- came up time and again, but, [[MemeticBadass being Batman]], doesn't really count.
*** The heroes actually abused this, by having Martian Manhunter pretend to be Superman in front of Lex Luthor to [[EngineeredPublicConfession get a confession for a crime]]. Once J'onn stops pretending to be weakened by the kryptonite, [[OhCrap a shocked Lex]] tries to shove it in his face to no effect.
*** Batman uses this trope against Amazo, a robot who can [[PowerCopying copy the abilities of superheroes]], after he copies Superman. While it works the first time, [[AdaptiveAbility Amazo eventually adapts and becomes immune to the effects of kryptonite]].
*** In ''Unlimited'', when [[Characters/DCAULexLuthor Lex Luthor]] was [[FreakyFridayFlip in the body of The Flash]] ("The Great Brain Robbery"), he took down Green Lantern with a cup of (yellow) pudding.
* In the ''WesternAnimation/DCSuperHeroGirls'', this is referenced by name when it turns out Wonder Woman -- who is still in high school and relatively young for her age -- goes from, in their words, [[TheAce "crushing it" in all matters]] to losing the ability to ''function'' outside of [[SmittenTeenageGirl adoring gibberish]] whenever she sees Steve Trevor, the first man she ever saw in the "World of Man". Supergirl, as one who knows the {{Trope Namer|s}} ''personally'', has issues with her experience being used as a point of comparison. ("''Kryptonite'' is Kryptonite. It's extremely painful, and awful, and ''that dude'' [Steve Trevor] is not Kryptonite.")

* A ''WesternAnimation/JusticeLeagueAction'' web short called True Colors has Firestorm try to transmute Metallo's Kryptonite into lead, but he doesn't know its composition well enough to do it accurately, and it goes through ''several'' of its variants, causing Superman to suffer each of its effects during the battle. Traditional Green has its traditional pain/weakness effect, Red sends him into a rage, and Black splits him into good/evil versions. Gold and Pink make their screen debuts but don't have their usual effects; Gold gives him amnesia instead of depowering him, and Pink turns him into a woman instead of making him act CampGay. (He keeps his very male voice, though!)

* In the ''WesternAnimation/TeenTitans2003'' cartoon, [[Characters/TeenTitans2003Starfire Starfire]] is allergic to metallic chromium. The allergy is more dangerous to others than herself, as it causes her to sneeze energy blasts. It even turns out to be an advantage, as it allows the team to track a chromium-based bomb. It's also a big case of artistic license, as chromium is used in a lot of common technologies.

* ''Series/GameOfThrones'': The wights and their decapitated limbs will only stop moving if (A) [[KillItWithFire they're set on fire]], (B) are so thoroughly torn apart that their individual joints cannot move, or (C) are stabbed by something associated with super-fire, like obsidian or Valeryan Steel. In the White Walkers' case, the obsidian causes them to scream for a few seconds as it sinks in before they disintegrate, while the Valeryan steel causes them to instantly disintegrate. The Night King is ''immune'' to fire and can only be defeated with Valeryan Steel, but this comes at the cost of being the [[KeystoneArmy keystone to his entire army]].

* In ''VisualNovel/TearsToTiara'' and the sequel ''VideoGame/TearsToTiara2'', non-humans on your team are affected whenever the bad guys use Obelisk to unleash the "holy" aura Gravitas.

* In ''Franchise/MegaMan'', all enemies have this. An extreme example is Metal Man from ''VideoGame/MegaMan2'', who dies in 1 hit from his own weapon (on Easy. On Hard mode he takes 2 shots).
* ''VideoGame/TwentyXX'', which is [[SpiritualSuccessor heavily inspired by]] ''VideoGame/MegaManX'', has the same kind of boss weakness cycle. Some of them make sense: the shield-focused Vile Visage is vulnerable to shield-breaching mortars, and the engineered plant Death Lotus can be trimmed with spinning blades. Others are a bit stranger; [[MoreDakka minigun-encrusted]] Perforator Alpha is susceptible to a slow-moving phasing projectile for reasons that are never quite explained.
* In ''VideoGame/TheElderScrollsVSkyrim'', [[DragonsAreDemonic draconic]] BigBad Alduin is completely invulnerable unless under the effects of the "[[BrownNote Dragonrend]]" [[LanguageOfMagic Thu'um]] shout. Dragonrend is the only Thu'um shout created by mortals, and it forces the immortal [[OurDragonsAreDifferent dragons]] to experience mortality, an utterly disorienting concept to them.

* ''VideoGame/FinalFantasyCrystalChroniclesEchoesOfTime'': The hero's crystal fragment triggers Veriaulde's transformation and harms Larkeicus, in both cases causing their bodies to smoke or steam.
* ''Franchise/TheLegendOfZelda'': In games like ''VideoGame/TheLegendOfZeldaALinkToThePast'', only the Silver Arrows and the Master Sword can harm Ganon.

* ''WebAnimation/{{RWBY}}'': Most humans aren't consciously aware of magnetism and Pyrrha can only affect people with her MagnetismManipulation power if they're wearing metal. Penny, however, is a robot that is made from a magnetic material. During the Vytal Festival tournament, the villains deliberately rig the fights so that Penny will be forced to fight Pyrrha to deliberately invoke this weakness. [[spoiler:When they trick Pyrrha into using her full power, Penny and her [[MarionetteMaster sword wires]] become so badly entangled by the force of the magnetic pulse that she ends up being torn to shreds by her own weapons.]]

* The [[OurDarkMatterIsMysterious Pa'anuri]] from ''Webcomic/SchlockMercenary'' are immune to attacks by baryonic matter (that is to say, 'normal' matter) because baryonic and dark matter does not interact outside of gravity. [[DestructiveTeleportation Teraporting]], meanwhile, disrupts their equivalent to biochemistry[[note]]teraporting in the Schlockiverse creates billions of tiny wormholes, which are gravitic events[[/note]] and is toxic to them, meaning that fighting Pa'anuri involves saturating areas with TeleportInterdiction fields or rapidly teraporting in their vicinity. In the final arc, [[BigGood The Fleetmind]] invents a Teraport Gun which weaponizes this factor: It's not made clear what its effect would be on a baryonic opponent, but it is extremely deadly to Pa'anuri.

* Interestingly, in ''WesternAnimation/SupermanTheAnimatedSeries'', it was originally planned that ComicBook/{{Supergirl}}, being in this iteration not from Krypton, but rather the sister-planet of Argos, would not have a weakness to Kryptonite. This is demonstrated in the "Superman Adventures" comic based on the series. By the time of ''WesternAnimation/JusticeLeague Unlimited'', though, the weakness was firmly in place.
* Spoofed in an episode of ''WesternAnimation/{{Freakazoid}}'', in which bad guy Guttierez tries presenting a variety of weaknesses (the color yellow, water, and kryptonite itself), failing each time, as Freakazoid points out that that's some other iconic character's weakness.
** Freakazoid himself has two rather obscure and ridiculous weaknesses, though: he can be imprisoned in a cage with graphite bars charged with negative ions, and he has an aversion to "poo gas".
---> '''Freakazoid:''' Dumb, dumb, dumb! Never tell the villain how to trap you in a cage!\\
'''Guttierez:''' You probably shouldn't have helped us build it, either.\\
'''Freakazoid:''' I know! Dumb!
*** Though as Guttierez pointed out, no one likes "poo gas".

* ''WesternAnimation/TinyToonAdventures'': In an episode spoofing the ''Film/SupermanFilmSeries'', "Super-Babs" was weak to carrot cake -- she couldn't stop eating it, and the villain continued feeding it to her until she was too overweight to fly after him.
* The ''WesternAnimation/JusticeLeague'' cartoon downplayed or ignored the Kryptonite Factor of every character ''except'' Superman. ComicBook/GreenLantern's vulnerability to yellow was never actually mentioned (though occasionally, if you watch closely, you'll see yellow stuff getting through his force barricades). [[ComicBook/MartianManhunter J'onn J'onnz]] had no particular vulnerability or [[WhyDidItHaveToBeSnakes phobia]] regarding fire (though he had a bad case of TheWorfEffect in the first season, and he would occasionally struggle in situations where there was a lot of fire). {{ComicBook/Aquaman}} never seemed overly discomfited by being out of water for extended periods. Characters/{{Wonder Woman|TheCharacter}}... well, she'd lost most of her Kryptonite Factors by the time the series started anyway. Hawkgirl eventually ''gained'' a Kryptonite Factor that was more emotional than physical and ended up resolved by series end anyway. [[Characters/DCAUTheFlash The Flash]] almost never used his powers to their full extent (not unlike Superman), with the idea that he never really pushed himself to excel...and when he did, he was given a convenient excuse not to again. [[Characters/DCAUBatman Batman]]'s "Kryptonite Factor"--that he was a perfectly mortal human--came up time and again, but, [[MemeticBadass being Batman]], doesn't really count.
** In ''Unlimited'', when [[Characters/DCAULexLuthor Lex Luthor]] was [[FreakyFridayFlip in the body of The Flash]] ("The Great Brain Robbery"), he took down Green Lantern with a cup of (yellow) pudding.
** The heroes used this trope against Amazo, a robot who can copy the abilities of superheroes.
** Heroes actually abused this, by having Martian Manhunter pretend to be Superman in front of Lex Luthor to get a confession for a crime.
* ''WesternAnimation/ThunderCats1985'': The [=ThunderCats=] are vulnerable to "thundrainium", a rare mineral that is a poorly-disguised knock-off of kryptonite. It even hurts Jaga, who is a ghost. For unexplained reasons, the villainous [=ThunderCat=] Grune the Destroyer is not affected by thundrainium, which makes him very dangerous as his mace is made of it.
* In the ''WesternAnimation/TeenTitans2003'' cartoon, [[Characters/TeenTitans2003Starfire Starfire]] is allergic to metallic chromium. The allergy is more dangerous to others than herself, as it causes her to sneeze energy blasts. It even turns out to be an advantage, as it allows the team to track a chromium-based bomb. It's also a big case of artistic license, as chromium is used in a lot of common technologies.
* The WesternAnimation/SushiPack are weakened by heat, and since they have a tendency to announce it, their most recurrent villains usually keep a couple of heat lamps around.

* ''WesternAnimation/BatmanTheBraveAndTheBold'':
** When Batman [[spoiler:received powers on the planet Zur-En-Arrh, the supervillain Rothul quickly figures out the new Superman-like Batman's weakness: Quartz]].
** Superman fell under the influence of Red Kryptonite. As mentioned above, in the comics it has a different one-off effect every time Superman is exposed to it, while in television it usually affects him mentally. This show has it both ways: Red K has random effects, and ''this'' time its effect is gonna be SuperDickery!
* In Composite Santa's first appearance on ''WesternAnimation/RobotChicken'', half of his body melted after a fireball destroyed another enemy. He exclaimed, "Temperatures over 32 degrees Fahrenheit! My only weakness!" This later became a MadLibsCatchphrase as "My only weakness" included bullets, water, and baseball bats.
* The animated film ''WesternAnimation/SupermanDoomsday'' contains an almost amusing example in that even ''Superman'' needed Kryptonite to defeat his clone with identical powers. Admittedly, the real Superman isn't quite at full strength at this point.
--> '''Superman''': You have all my strengths... and weaknesses.
* A ''WesternAnimation/JusticeLeagueAction'' web short called True Colors has Firestorm try to transmute Metallo's Kryptonite into lead, but he doesn't know its composition well enough to do it accurately, and it goes through ''several'' of its variants, causing Superman to suffer each of its effects during the battle. Traditional Green has its traditional pain/weakness effect, Red sends him into a rage, and Black splits him into good/evil versions. Gold and Pink make their screen debuts but don't have their usual effects; Gold gives him amnesia instead of depowering him, and Pink turns him into a woman instead of making him act CampGay. (He keeps his very male voice, though!)
* Specifically parodied in one episode of the ''WesternAnimation/EarthwormJim'' animated series. Jim is helpless against the substance known as Wormtonite (which Peter Puppy claims they found at the back of the fridge, and might once have been cheese). Bizarrely, its effects include turning Jim into a bowl of candied corn.
* ComicBook/SpiderMan would occasionally make sly references to a "guy who's allergic to green rocks".

* ''WesternAnimation/TheSimpsons'': Bart once discovered Principal Skinner's allergy to peanuts, and used it to practically enslave him. Skinner soon learns that Bart has an allergy too; Shrimp. [[MundaneMadeAwesome They end up in a "sword" fight with sticks with their opponent's kryptonite on the end]] set to "[[AwesomeMusic/StarWars Duel of the Fates]]".
* ''WesternAnimation/DannyPhantom'':
** Danny is weakened by a flower called Blood Blossom. It removes his powers while causing him extreme pain. Plus the various weapons his parents and Vlad have devised that can remove his powers or hurt him while he is intangible.
** Ectoranium, introduced in the SeriesFinale, is a green glowing rock that ghosts can't touch without being painfully shocked (in fact, it's the key ingredient in most anti-ghost weapons and defensive technology); they can still phase through it, which is an important plot point. Kind of an obvious {{Expy}} of Kryptonite, but in this case the Ectoranium is as much of a danger to humans as ghosts since it's a large asteroid that got knocked off course towards Earth.

* ''WesternAnimation/TeenageMutantNinjaTurtles1987'' parodied this in the episode "Michelangelo Meets Bug Man". In it, Michelangelo finds Bug Man, who turned into the superhero when he got angry, wrapped in chains that were laced with his main weakness before being thrown down into the sewer. His weakness? "Leestanite"! [[note]]The name is not an accident: it was a play on famous comic book creator Creator/StanLee.[[/note]]
* In ''WesternAnimation/MyLittlePonyAndFriends'', Grogar is incredibly powerful and seemingly nothing can hurt him, but once a certain bell is rung, he is automatically banished back to the Shadow World.
* In ''WesternAnimation/AvatarTheLastAirbender'', earthbenders can't bend metal (until Toph discovers how). In ''WesternAnimation/TheLegendOfKorra'', metalbending techniques have become widespread, so the new kryptonite is platinum. Metalbending works by bending impurities within the metal, and platinum doesn't have enough impurities to bend.
** Most of the Bending arts have some hard counter that can be used to imprison troublesome Benders, usually by denying them access to their element in some way or another. Earth has the aforementioned metal (which can still be effective since ''Legend of Korra'' noted that only a few Earthbenders have the skills needed to become Metalbenders), and Earthbenders have also been shown to be useless when put in wooden containers. Firebenders and Waterbenders are vulnerable to extreme cold and heat respectively, and since they draw their powers from the celestial bodies eclipses can also shut them down for a short time. Air is the only one without an expressed weakness, but a few heavy chains or a straitjacket are usually enough to keep an Airbender from going anywhere.
* In the [[Recap/MyLittlePonyFriendshipIsMagicS6E26ToWhereAndBackAgainPart2 season 6 finale]] of ''WesternAnimation/MyLittlePonyFriendshipIsMagic'', Thorax reveals that Queen Chrysalis has a throne carved from an ancient dark stone that absorbs all forms of magic that get too close to it except for changeling magic. Not even [[RealityWarper draconequus]] magic can resist it.
* On ''WesternAnimation/TheFairlyOddParents'', fairy magic has no effect on butterfly nets, which, therefore, are one of if not the only object capable of trapping them.
** Genies are affected by a substance called smoof. What smoof is goes unexplained, but it's consistently purple.
* In the ''WesternAnimation/DCSuperHeroGirls'', this is referenced by name when it turns out Wonder Woman -- who is still in high school and relatively young for her age -- goes from, in their words, [[TheAce "crushing it" in all matters]] to losing the ability to ''function'' outside of [[SmittenTeenageGirl adoring gibberish]] whenever she sees Steve Trevor, the first man she ever saw in the "World of Man". Supergirl, as one who knows the {{Trope Namer|s}} ''personally'', has issues with her experience being used as a point of comparison. ("''Kryptonite'' is Kryptonite. It's extremely painful, and awful, and ''that dude'' [Steve Trevor] is not Kryptonite.")
* In ''WesternAnimation/AmericanDragonJakeLong'', dragons can't stand Sphinx hair. Small amounts force them back into human form, while large amounts inflict serious pain upon them.
* [[BigBad Aku]] from ''WesternAnimation/SamuraiJack'' is immune to all forms of damage except divine magic, so the gods created a magic sword forged from the righteous spirit of a Japanese Emperor to kill him. When that didn't stick, the Emperor had his son trained up to finish the job [[spoiler: and eventually, he succeeded.]]
** As a bonus, the sword cannot harm an innocent when it is in the hands of evil, so Jack himself can't be hurt by the weapon if it is used by a villain, as demonstrated when Aku once tried to stab him with the sword and it just bounced off.
* The ''WesternAnimation/HeroElementary'' episode "Sara Loses Her Snap" reveals that Sara Snap loses her powers for a day when she eats coconuts as shown when accidentally eating a coconut flavored power bar. This becomes a problem when the team has to move a giant hamburger out of the way.
* ''WesternAnimation/{{Ninjago}}'': The Ninja's ElementalPowers can be neutralised by a mineral known as Vengestone.

* In ''WesternAnimation/JusticeLeagueCrisisOnTwoEarths'', Superman's EvilDoppelganger Ultraman is weak to blue kryptonite rather than green (like Bizarro).

* Cole on ''Series/{{Tracker}}'' was vulnerable to Lodestone - it interfered with his life force sensing ability and weakened him a bit.

* ''WebAnimation/HappyTreeFriends'': Being an {{Expy}} of {{Franchise/Superman}}, Splendid has kryptonut in [[Recap/HTFGemsTheBreaks one episode]], which is kryptonite shaped as an acorn. Exposure to the radiation from it causes him to lose his powers and fall ill with what resembles the stomach flu. At the end of the episode, he crushes the kryptonut and accidentally inhales the powder, causing him to vomit uncontrollably as the skin on his face falls off. This (and [[RecapHTFClassAct another instance]] confirmed by WordOfGod) is the only time he has ever died, as nothing else can hurt him.

* ''WebAnimation/HappyTreeFriends'': Being an {{Expy}} of {{Franchise/Superman}}, Splendid has kryptonut in one episode, which is kryptonite shaped as an acorn. Exposure to the radiation from it causes him to lose his powers and fall ill with what resembles the stomach flu. At the end of the episode, he crushes the kryptonut and accidentally inhales the powder, causing him to vomit uncontrollably as the skin on his face falls off. This (and another instance confirmed by WordOfGod) is the only time he has ever died, as nothing else can hurt him.

The name comes from kryptonite, the bane of ComicBook/{{Superman}} regardless of [[StrongAsTheyNeedToBe how powerful he is being portrayed at the time]]. A literal {{green rock|s}}, it seemed unusually abundant in supervillainous hands for being radioactive bits of a planet that exploded lightyears away. Many {{Elseworld}}s and spin offs to the ''Superman'' mythos include characters who are more resistant to kryptonite, but conveniently, not as strong. Thanks to ''ComicBook/{{Superman}}'' being a {{Long Runner|s}}, and PopCulturalOsmosis, a common bit of MemeticMutation is to refer to something you are particularly vulnerable to as "My Kryptonite".

** ''Film/BatmanVSupermanDawnOfJustice'' has Kryptonite discovered among the wreckage of the [[DoomsdayDevice Kryptonian World Engine]] near India after the events of ''Man of Steel''. It's explained as a radioactive isotope that actively harms Kryptonian cells. Before a large chunk is found in the Indean Ocean, the most they could find was only good for surgical tools. [[AdaptationalWimp In contrast to most portrayals, a small amount has no effect just in proximity.]] [[spoiler:Batman develops Kryptonite-laced gas grenades at his best bet at subduing Superman, with a spear as a FinishingMove.]] This also applies to [[spoiler:Doomsday, who is Kryptonian in origin and just as vulnerable to Kryptonite.]]

* ''Film/XMenApocalypse'': Nightcrawler's teleportation power is blocked by electrical fields. They also interfere with Jean Grey's telekinesis and telepathy.e

* In ''Literature/AfterTheGoldenAge'', Captain Olympus is a {{Nigh Invulnerab|ility}}le FlyingBrick, but he has one weakness: [[spoiler:the same radiation that originally gave him his powers]].

* The ''WesternAnimation/JusticeLeague'' cartoon downplayed or ignored the Kryptonite Factor of every character ''except'' Superman. Franchise/GreenLantern's vulnerability to yellow was never actually mentioned (though occasionally, if you watch closely, you'll see yellow stuff getting through his force barricades). [[ComicBook/MartianManhunter J'onn J'onnz]] had no particular vulnerability or [[WhyDidItHaveToBeSnakes phobia]] regarding fire (though he had a bad case of TheWorfEffect in the first season, and he would occasionally struggle in situations where there was a lot of fire). {{ComicBook/Aquaman}} never seemed overly discomfited by being out of water for extended periods. Franchise/WonderWoman... well, she'd lost most of her Kryptonite Factors by the time the series started anyway. Hawkgirl eventually ''gained'' a Kryptonite Factor that was more emotional than physical and ended up resolved by series end anyway. Franchise/TheFlash almost never used his powers to their full extent (not unlike Superman), with the idea that he never really pushed himself to excel...and when he did, he was given a convenient excuse not to again. {{Franchise/Batman}}'s "Kryptonite Factor"--that he was a perfectly mortal human--came up time and again, but, [[MemeticBadass being Batman]], doesn't really count.
** In ''Unlimited'', when ComicBook/LexLuthor was in the body of The Flash ("The Great Brain Robbery"), he took down Green Lantern with a cup of (yellow) pudding.

* ''WesternAnimation/Thundercats1985'': The [=ThunderCats=] are vulnerable to "thundrainium", a rare mineral that is a poorly-disguised knock-off of kryptonite. It even hurts Jaga, who is a ghost. For unexplained reasons, the villainous [=ThunderCat=] Grune the Destroyer is not affected by thundrainium, which makes him very dangerous as his mace is made of it.
* In the ''WesternAnimation/TeenTitans'' cartoon, ComicBook/{{Starfire}} is allergic to metallic chromium. The allergy is more dangerous to others than herself, as it causes her to sneeze energy blasts. It even turns out to be an advantage, as it allows the team to track a chromium-based bomb. It's also a big case of artistic license, as chromium is used in a lot of common technologies.

* In the ''WesternAnimation/DCSuperHeroGirls'', this is referenced by name when it turns out Wonder Woman -- who is still in high school and relatively young for her age -- goes from, in their words, [[TheAce "crushing it" in all matters]] to losing the ability to ''function'' outside of [[SmittenTeenageGirl adoring gibberish]] whenever she sees Steve Trevor, the first man she ever saw in the "World of Man". Supergirl, as one who knows the TropeNamer ''personally'', has issues with her experience being used as a point of comparison. ("''Kryptonite'' is Kryptonite. It's extremely painful, and awful, and ''that dude'' [Steve Trevor] is not Kryptonite.")

* [[http://blogs.discovermagazine.com/notrocketscience/2011/03/29/why-is-aspirin-toxic-to-cats/ Aspirin is kryptonite to cats]]. This article even acknowledges the trope.

* Imaginary Man, a superhero imaginary friend on ''WesternAnimation/FostersHomeForImaginaryFriends'', is weakened by girly things, particularly flowers. Similarly, his evil nemesis Nemesis, loses her powers whenever her hair is messed up. It later turns out they were thought up by a boy and his sister, respectively, just to annoy each other.