Kryptonite is a fictional material that appears primarily in Superman stories published by DC Comics. In its best-known form, it is a green, crystalline material originating from Superman's home world of Krypton that emits a unique, poisonous radiation that can weaken and even kill Superman and other Kryptonians. Kryptonite radiation can be transmitted through any element except lead. There are other varieties, such as red kryptonite and gold kryptonite, which have different but still generally negative effects.
Adversaries of Superman and other characters are frequently depicted using kryptonite against Superman, with Lex Luthor incorporating it into weapons, Metallo using it as power, and Titano able to project Kryptonite radiation from his eyes.
Kryptonite has entered common usage as a metaphor for a particular weakness or vulnerability, similar to an "Achilles' heel".
History
An unpublished 1940 story titled "The K-Metal from Krypton", written by Superman creator Jerry Siegel, featured a prototype of kryptonite. It is a mineral from the planet Krypton that drains Superman of his strength and gives superhuman powers to humans. This story was rejected because Superman reveals his identity to Lois Lane.
The mineral kryptonite, not to be confused with the real element krypton, was officially introduced in the radio serial The Adventures of Superman, in the story "The Meteor from Krypton", broadcast in June 1943."Only one arc in 1943 managed to transcend its era: "The Meteor from Krypton". Debuting on June 3, it marked the debut of kryptonite ..." An apocryphal story claims that kryptonite was introduced to incapacitate Superman, allowing Superman's voice actor Bud Collyer to take time off. This tale was recounted by Julius Schwartz in his memoir.pg 132-133 However, historian Michael J. Hayde disputes this. In "The Meteor from Krypton", Superman is never exposed to kryptonite. If kryptonite allowed Collyer to take vacations, that was a fringe benefit discovered later. More likely, kryptonite was introduced as a plot device for Superman to discover his origin."Since Superman's life isn't threatened — the meteorite never leaves the doctor's custody — it's likely that Lowther's primary intent was to create a means for Superman to discover his own origin". Hayde may have mistaken 1943's "The Meteor from Krypton" for 1945's "The Meteor of Kryptonite", as Superman was exposed in the latter but not in the former.
In the radio serial, Krypton is located in the same solar system as Earth, in the same orbit, but on the opposite side of the Sun. This provided an easy explanation for how kryptonite found its way to Earth. In the comics' Silver Age, Krypton is located in a distant solar system and much of the kryptonite that came to Earth was transported by the same "space warp" that baby Kal-El's rocket traversed.
Kryptonite was incorporated into the comic mythos with Superman #61 (November 1949). In a 1993 interview with Florida Today, editor Dorothy Woolfolk stated that she felt Superman's invulnerability was "boring".
Originally depicted as an element in the Golden, Silver, and Bronze Age comics, Kryptonite is depicted as a compound in post-Crisis continuity.Action Comics #591 (August 1987)
Varieties Various forms of the fictional material have been created over the years in Superman publications and programs. This table includes forms that have not persisted in canon.
TypeFirst appearanceOriginEffects by genetic origin In other mediaKryptonDaxamEarthBizarro WorldKrypton-3FilmTelevisionVideo gamesLive-actionAnimatedLive-actionAnimated Green The Adventures of Superman radio serial, "The Meteor from Krypton" (June 1943) Comics: Action Comics #161 (August 1951)Fragments from Krypton’s destruction travelling through a space warp alongside baby Kal-ElLoss of superpowersSevere, intensifying painIntensifying breathing issuesSevere muscular weaknessFeverGreen blood or skinEventual fatalityNon-accumulativeMitigated by copious yellow sunlight exposureBlocked by leadNeutralized by Kal-El's ship (Smallville)With prolonged exposure: carcinogenesisPossible cancer treatmentVarying genetic mutations (Smallville)Temporary absorption of Kryptonian powers via electricity (Smallville)Synthetic medical applications (Smallville)Bizarro: perfect healthBizarro World humans: temporary superpowers (Superman & Lois) Superman serial Atom Man vs. Superman Superman (1978) Superman III Superman Returns Batman v Superman: Dawn of Justice Superman (2025) Supergirl (2026) Superman: Doomsday Superman/Batman: Public Enemies Justice League: Doom DC Animated Movie Universe DC League of Super-Pets Scooby-Doo! and Krypto, Too! Batman Ninja vs. Yakuza League Adventures of Superman Superboy Lois & Clark: The New Adventures of Superman SmallvilleScharping, Nathaniel (April 4, 2018). "Space Metal Has Captivated Humanity for Ages" . Discover. Arrowverse Titans Superman & Lois The Brady Kids Super Friends Superman (1988) DC Animated Universe Krypto the Superdog Legion of Super Heroes The Batman Batman: The Brave and the Bold Young Justice Justice League Action DC Super Hero Girls My Adventures with Superman Superman (1979) Superman (1987) Superman: The New Superman Adventures Mortal Kombat vs. DC Universe Lego Batman 2: DC Super Heroes Scribblenauts Unmasked: A DC Comics Adventure Lego Dimensions Injustice: Gods Among Us Injustice 2 Red Superman #61 (November 1949)Traversal through radiated spaceMars (Adventure Comics #255, 1958)Loss of heroism and inhibitionsUnpredictable effectsCounteracted by green (Smallville)Stronger form of green (prior to Adventure Comics #252, September 1958 only) Unpredictable effects (prior to Superman's Pal Jimmy Olsen #80, October 1964 only)In bloodstream: same as on Kryptonians (Smallville)Hair loss (Super-Pets)DC League of Super-PetsSuperboy Lois & Clark Smallville Supergirl (2015) TitansSuper Friends Batman: The Brave and the Bold Krypto the Superdog Justice League Action DC Super Hero GirlsSuperman (1987) Scribblenauts Unmasked-green-whiteSuperman #404 (February 1958) Superpower restoration-greenAction Comics #275 (April 1961)Created by BrainiacUnpredictable effectsLoss of superpowers-blueSuperman #162 (July 1963)Invented by SupermanGreen charged with "quantum battery" (Justice League Action)Splitting into uninhibited red being and logical blue beingSame as on Kryptonians (Justice League Action)Justice League ActionBizarro-Superman's Pal, Jimmy Olsen #80 (October 1964)Bizarro humans: Ridding of Bizarro stateSuperman's Pal Jimmy Olsen #80, October 1964Humans: Same as red on KryptoniansBatman/Superman: World's Finest #12Scribblenauts Unmasked-goldSuperman #178 (July 1965)Temporary memory loss-green-goldSuperman #192 (January 1967) Permanent superpower lossPermanent memory lossPositivePlatinum "All that Glitters," Adventures of Superman TV series (1958)Comics: Batman Secret Files #1 (December 2018) Impossible world (dream of Jimmy Olsen, Adventures of Superman TV series/impossible world inside Phantom Zone, comics)Source of superpowers (Adventures of Superman TV series)Permanent Kryptonian powersAdventures of SupermanNegativeGold"All that Glitters," Adventures of Superman TV series (1958)Comics: Adventure Comics #299 (August 1962)Dream of Jimmy Olsen (Adventures of Superman TV series)Green affected by "atomic radiation"Permanent loss of superpowersTemporary memory loss (Justice League Action)Ultraman: Permanent scar (Smallville)Adventures of Superman Smallville Super Friends Justice League ActionScribblenauts Unmasked Injustice 2Anti-Fool'sSlowHybridAction Comics #252 (May 1959)Created by Metallo (The Brave and the Bold #175, June 1981)Created by Professor Jefferson Cole at S.T.A.R. Labs (Lois & Clark)NoneSame as green on KryptoniansUltraman: Perfect healthLois & ClarkScribblenauts UnmaskedX-Orange Action Comics #261 (January 1960)Experiment by Supergirl to counteract greenFragments from Krypton (Superman & Lois/Super-Pets) None Temporary superpowers Paranoia (DC Super Hero Girls)Counteracted by green (Superman & Lois, Super-Pets) Bizarro: same as green on Kryptonians (Superman & Lois)DC League of Super-PetsSuperman & LoisScribblenauts UnmaskedBlueSuperman #140 (October 1960)Green subjected to Professor Dalton's duplicator rayRare fragments among Krypton's remains (Super Friends)Harm to soulSuspended superpowers (Smallville)Counteracts red (Super Friends)Medical stability (Smallville)Bizarro: same as green on KryptoniansBizarro: death through overcharging (Smallville)Bizarro: logical thoughtUltraman: perfect health/same as green on Kryptonians (Justice League: Crisis on Two Earths)Blocked by "imperfect" leadJustice League: Crisis on Two EarthsSmallville SupergirlSuper FriendsScribblenauts UnmaskedWhiteAdventure Comics #279 (December 1960)Green affected by "space cloud"Kills microbes and vegetationKills microbes and vegetationScribblenauts UnmaskedBizarro-"The Battle with Bizarro," Superboy TV series (November 18, 1989)Cellular healthCellular normality (Superboy TV series)SuperboyYellowAction Comics #277 (June 1961)Created by LuthorIntimidation (Action Comics #277, June 1961)Unknown (Superman Family Adventures Vol. 12, August 2012)Fear (Lego DC Super Hero Girls)Lego DC Super Hero GirlsScribblenauts UnmaskedSilver Superman's Pal, Jimmy Olsen #70 (July 1963)Hoax by Jimmy OlsenBrainiac technology (Smallville, comics following Superman/Batman #46, April 2008)Paranoid delusionsSmallville SupergirlScribblenauts UnmaskedJewelAction Comics #310 (March 1964)Kryptonian mountain fragments in Phantom ZoneMind control powersSmallvilleMagno-Superman's Pal, Jimmy Olsen #92 (April 1966)Created by Mr. NeroMagnetic attractionScribblenauts UnmaskedTar-basedBlackHarun-ElSuperman III (1983)Comics: Supergirl (vol. 5) #2 (October 2005)Synthesized with tar (Superman III)Superheated green (Smallville)Fragments of KryptonKryptonian religion (Supergirl TV series)Mental/physical manifestation of empowered evil self and weakened good selfReversion by additional exposure (Smallville/Supergirl TV series)Same as on Kryptonians (Smallville/Supergirl TV series)Superman IIISmallville SupergirlJustice League ActionScribblenauts UnmaskedKrimsonSuperman Volume 2 #49 (November 1990)Created by Mister Mxyzptlk One wish grantedReversion by disclosure of originKryptisium-XThe Adventures of Superman #511 (April 1994)Green filtered by EradicatorExcessive superpowersScribblenauts UnmaskedPink Supergirl (vol. 4) #79 (April 2003)Inversion of gender-stereotyped traitsReversed sex (Justice League Action)Justice League ActionPurple“Streaky's Supercat Tale,” Krypto (April 2005)Comics: Superman: The Kryptonite Spectrum #1 (2025)Disordered thoughts and suggestibility Same as on Kryptonians (Super-Pets)DC League of Super-PetsKrypto the SuperdogDC Super Hero Girls Opal Earth 2 #0 (November 2012) Created by Mr. Terrific Severe mental instabilityOne use only Periwinkle Superman Family Adventures #9 (March 2013)JoyTransmutation to periwinkle colorBizarro: anger (DC Super Hero Girls)DC Super Hero GirlsTurquoise Dark Nights: Death Metal #3 (August 2020)Dark MultiverseTransformation into mythical creatureAmberDark Knight: Death Metal - The Last 52: War of the Multiverses #1 (February 2021)Dark multiverse Loss of superpowers to human Gain of superpowers from KryptonianCobaltSuperman: The Kryptonite Spectrum #2 (2025)Size increaseSpeckledSuperman: The Kryptonite Spectrum (2025)Size decrease RainbowSuperman: The Kryptonite Spectrum #4 (November 2025)Distress signal from Fifth Dimension Transferral to Fifth Dimension
In vernacular