Green kryptonite as seen in Superman: Secret Origin #1
Publication information
PublisherDC Comics
First appearance
In story information
Element of stories featuring

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 Kryptonians. Kryptonite radiation can be transmitted through any element except lead. Thus, Superman has a special lead suit to protect himself from the radiation. There are other varieties of kryptonite, such as red and gold kryptonite, which have different but still generally negative effects.

Batman, Lex Luthor, Metallo, and Titano are four notable characters often presented as using kryptonite — the first carrying the substance as a last-ditch method to stop his ally (often at Superman's urging to take such precautions) if he is subject to mind control or otherwise compromised, the next two using the mineral to ward off Superman or incorporating it into weapons, and the fourth being able to project rays of kryptonite radiation from his eyes after being altered by simultaneous exposure to kryptonite and uranium.[1]

Due to Superman's popularity, kryptonite has become a byword for an extraordinary exploitable weakness, synonymous with "Achilles' heel".


Superman suffering from green kryptonite poisoning, courtesy of foes Metallo and Titano the Super-Ape, in Action Comics Annual #10 (March 2007), art by Art Adams and Alex Sinclair.

An unpublished 1940 story titled "The K-Metal from Krypton", written by Superman creator Jerry Siegel, featured a prototype of kryptonite. It was a mineral from the planet Krypton that drained Superman of his strength while giving superhuman powers to humans. This story was rejected because in it Superman reveals his identity to Lois Lane.[2]

The mineral known as kryptonite, not to be confused with the real element krypton, was first officially introduced in the radio serial The Adventures of Superman, in the story "The Meteor from Krypton", broadcast in June 1943.[3] An apocryphal story claims that kryptonite was introduced to give Superman's voice actor, Bud Collyer, the possibility to take a vacation at a time when the radio serial was performed live. In an episode where Collyer would not be present to perform, Superman would be incapacitated by kryptonite, and a substitute voice actor would make groaning sounds. This tale was recounted by Julius Schwartz in his memoir.[4] However, the 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.[5] On the other hand, Hayde might have mistaken 1945's "The Meteor of Kryptonite" for 1943's "The Meteor from Krypton", as Superman was exposed in the latter but not in the former.[6]

In the radio serial, Krypton was 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. During the comics' Silver Age, which put Krypton in another solar system light-years away, much of the kryptonite that came to Earth (along with several Kryptonian artifacts) was explained as having come through the same "space warp" that baby Kal-El's rocket traversed.

Kryptonite was incorporated into the comic mythos with Superman #61 (November 1949).[7] Editor Dorothy Woolfolk stated in an interview with Florida Today in August 1993 that she felt Superman's invulnerability was "boring".[8]

Long said to be an element in the Golden, Silver, and Bronze Age comics, Kryptonite became a compound post-Crisis as revealed in Action Comics #591.

Forms, colors and effects

Various forms of the fictional material have been created over the years in Superman publications and programs.[9]

Green kryptonite Originally red in color, the material debuted in Superman #61 (Nov. 1949) and did not adopt its characteristic green hue until Action Comics #161 (Aug. 1951). Green kryptonite weakens Superman and other Kryptonians, and is fatal with long-term exposure.[10] Kryptonians under green kryptonite's effects experience severe muscular weakness, usually to the point of collapse, and excruciating pain, with both conditions progressively intensifying. They often develop a fever and eventually will lose consciousness before death. The mineral will also gradually turn a Kryptonian's skin and blood green. Although canonical depictions vary widely, the majority of accounts maintain that, although green kryptonite exposure victims experience severe weakness and pain, exposure in itself does not eradicate the victim's superpowers, except those related to physical strength. Green kryptonite exposure does not compromise the subject's invulnerability to other forms of injury; therefore, it is not a practical strategy for a villain to first expose the victim to green kryptonite, then kill them with a gun or other conventional weapon. However, some enemies have occasionally used weapons with green kryptonite projectile ammunition, which can not only seriously wound a Kryptonian, but also make surgical treatment difficult, with resistance to injury in a yellow sun environment being a major complication. In one such incident, the surgeon was forced to give Superman controlled exposure to the mineral to make proper incisions.[11] Some accounts maintain paralysis is an effect of green kryptonite exposure, although most depictions show victims still capable of limited movement. The effects of green kryptonite are not cumulative: a Kryptonian who can be removed from kryptonite exposure in time will fully recover from its effects with no lasting medical repercussions no matter how many instances of surviving exposures.[12] Kryptonian characters have been shown to become immune to green kryptonite due to either long-term absorption of sunlight[13] or extremely high short-term exposure to the Sun.[14] Post-Crisis sources establish that green kryptonite is also harmful to humans; with sufficient long-term exposure, it can result in cancer, as Lex Luthor discovered, much to his dismay, from a ring with a green kryptonite jewel he wore to ward off Superman. At least one comic, however, also mentioned that kryptonite was being investigated as a possible cancer treatment.[15]
Positive kryptonite Debuted in "All That Glitters" (1958), the last episode of Adventures of Superman. Professor Pepperwinkle isolates positive kryptonite from green kryptonite. It appears as yellow capsules on screen. It is said to be what gives Superman his powers and is also shown to give humans the abilities of Superman when both Lois Lane and Jimmy Olsen ingest it. This turns out to be a hallucination Jimmy Olsen had after being hit in the head with a sandbag.
Negative kryptonite Also debuted in the last episode of Adventures of Superman "All That Glitters" (1958). Professor Pepperwinkle isolates negative kryptonite from green kryptonite. It is said to have the ability to take away Superman's powers. This, as well, turns out to be a hallucination Jimmy Olsen had after being hit in the head with a sandbag.
Red kryptonite Debuted in Adventure Comics #252 (Sept. 1958). Originally red kryptonite simply weakened Superman, but to a greater degree than green kryptonite. Red kryptonite was later shown to cause odd behavior or bizarre transformations, albeit temporary and non-fatal. The effects of red kryptonite typically last anywhere from one day (24 hours) to two days (48 hours), although in some accounts the effects may persist up to three days (72 hours) or even several weeks.[16] In Smallville, red kryptonite affects Clark's mental state and the effect wears off as soon as he stops being in close proximity to it. Under the personality of "Kal", Clark becomes selfish and uses his powers recklessly, shown drinking and philandering. On Lois & Clark: The New Adventures of Superman, red kryptonite initially makes Superman apathetic, while another piece transfers his superpowers into other humans when used as a laser generator, and a third case causes him to lose fine control of his powers.
Anti-kryptonite/fool's kryptonite Debuted in Action Comics #252 (May 1959). Resembles green kryptonite, and has the same effect as it on humans, but is harmless to Kryptonians. It is also the power source for one version of Ultraman, Superman's evil counterpart from an antimatter universe.[17]
X-kryptonite Debuted in Action Comics #261 (Jan. 1960). Created by Supergirl in an unsuccessful attempt to find an antidote to green kryptonite. Harmless to Kryptonians, the mineral gives normal lifeforms superhuman abilities, as in the case of Supergirl's pet, Streaky the Supercat. Revised in Superman Family #203 (Oct. 1980) to have the same effect as the green variety on Kryptonians.

In Superman & Lois, X-kryptonite is only found in Smallville and has a yellowish hue. It gives humans one Kryptonian power, which varies depending on the person, and makes them more susceptible to having a Kryptonian consciousness implanted in them. It also weakens people from the Bizarro World.

Blue kryptonite Debuted in Superman #140 (Oct. 1960). An imperfect variety of kryptonite that is harmful to Bizarro and other Bizarro characters in the same way that green kryptonite affects Kryptonians. The only substance in the universe that its radiation cannot penetrate is imperfect lead. In the Super Friends franchise, it is also an antidote to the effects of red kryptonite. In Smallville, blue kryptonite temporarily nullifies the powers of Kryptonians, but also supercharges bodies to dangerous levels; this effect killed Bizarro. When a Kryptonian is in close proximity to blue kryptonite even as jewelry, he (or she) has no powers, but once separated by a sufficient distance, the powers return. Blue Kryptonite can also affect humans and plant life, putting them in a perfect state of health, but can cause irregularities.
White kryptonite Debuted in Adventure Comics #279 (Dec. 1960). Kills all plant life as well as bacteria and viruses.
Red-green kryptonite (first version) Debuted in Action Comics #275 (April 1961). An alloy created by the villain Brainiac, red-green kryptonite caused Superman to mutate, temporarily growing a third eye in the back of his head.
Gold kryptonite Debuted in Adventure Comics #299 (Aug. 1962). Kryptonite affected by atomic radiation, capable of permanently removing a Kryptonian's ability to process yellow sunlight, thus nulifying all of their powers. In post-Crisis stories, however, it only removes a Kryptonian's powers temporarily.[18]
Red-green-blue-gold kryptonite Debuted in Superman #162 (July 1963). An imaginary story in which Superman combines the minerals to power an intelligence-expanding device. An explosion occurs and splits Superman into two beings ("Superman-Red" and "Superman-Blue"), both of whom possess enhanced intelligence.
Silver kryptonite Debuted in Superman's Pal, Jimmy Olsen #70 (July 1963). Revealed by Jimmy Olsen to be a hoax. In post-Crisis stories, silver kryptonite first appeared in Superman/Batman #46 (April 2008), modeled after the version that appeared in the Smallville TV series in season five episode "Splinter", where Clark suffers paranoid delusions. Silver kryptonite causes Kryptonians to suffer from altered perceptions, loss of inhibitions and extreme hunger cravings. On the Supergirl TV series, this kryptonite causes Superman to hallucinate his "greatest fear" of an attacking General Zod during the final episode of season 2, "Nevertheless, She Persisted".
Jewel kryptonite Debuted in Action Comics #310 (March 1964). Made from the fragments of Krypton's Jewel Mountains, it amplifies the psychic powers of the criminals imprisoned in the Phantom Zone.
Bizarro-red kryptonite Debuted in Superman's Pal, Jimmy Olsen #80 (Oct. 1964). Affects humans in the same way that red kryptonite affects Kryptonians.
Red-green kryptonite (second version) Debuted in Superboy Comics #121 (June 1965). This variety caused Superboy to lose his superpowers permanently, but the Phantom Zone criminal Vakox unwillingly cured him, thus restoring his superpowers.
Red-gold kryptonite Debuted in Superman #178 (July 1965). Temporarily deprives Kryptonians of their memories.
Magno-kryptonite Debuted in Superman's Pal, Jimmy Olsen #92 (April 1966). Created by the villain Mr. Nero, this variety is magnetically attracted to all substances originally from Krypton.
Red-green-gold kryptonite Debuted in Superman #192 (Jan. 1967). An imaginary story in which the alloy permanently removes Superman's powers and memories of being Superman.
Slow kryptonite Debuted in The Brave and the Bold #175 (June 1981). A modified variety of green kryptonite produced by the supervillain Metallo that affects humans in a manner similar to how green kryptonite affects Kryptonians.
Kryptonite-X Debuted in The Adventures of Superman #511 (April 1994). A one-time fluke, kryptonite-X was created when the Eradicator filtered a harmful barrage of kryptonite discharged by Cyborg Superman at Superman. The result was beneficial for Superman, supercharging him and restoring his ability to process solar radiation.
Clear kryptonite Debuted in Smallville's "Visage" (Season 2, episode 11) on January 14, 2003. Clear kryptonite is green kryptonite that has been neutralized of all radiation and is thus completely harmless.
Pink kryptonite Debuted in Supergirl (vol. 4) #79 (April 2003). Pink kryptonite turns Kryptonians into homosexuals or effeminates. This type of kryptonite was mentioned in a single panel in a story that was a satire of the plots of many Silver Age comic book stories that featured some strange new variety of kryptonite, and is thus not considered canon in comics continuity. In the Justice League Action short "True Colors", due to the kid-friendly nature of the show, it instead switches a Kryptonian's physical sex.
Orange kryptonite Debuted in Krypto the Superdog #4 (Feb. 2007). Provides super-abilities to any animal that comes into contact with it for one day (24 hours).
Periwinkle kryptonite Debuted in Superman Family Adventures #9 (March 2013). A non-canonical variety that causes Kryptonians to lose all their inhibitions.
Platinum kryptonite Debuted in "True Strength", a story from Batman Secret Files #1 (Dec. 2018) and Batman (vol. 3) #85 (Feb. 2020). It is from "an impossible universe inside the Phantom Zone, on an impossible planet". When touched by a normal human, platinum kryptonite changes their cells in an instant, giving them Kryptonian superpowers for life. It is used by Batman to restore Gotham Girl's powers. Kong Kenan was also given superpowers from that type of kryptonite after the death of the New 52 Superman.
Turquoise kryptonite Debuted in Dark Nights: Death Metal #3 (Aug. 2020). A variant of Kryptonite from one of the worlds found in the Dark Multiverse, it is used by Darkfather (a version of Batman who attained Darkseid's powers) to torture Superman. It appears to have a similar effect on Kryptonians as green kryptonite.
Pilbeam kryptonite Debuted in "True Strength", a piece of unrecognisable kryptonite was discovered on the Phantom Zone by Superman's ally Joseph Pilbeam. The effects of this kryptonite are similar to platinum kryptonite, though for Kryptonians the effects are the opposite.
Superman and Jimmy Olsen discuss the mineral kryptonite, with the jewel variant making its debut, in Action Comics #310 (March 1964), art by Curt Swan.

In other media


Live action



Video games


Columbia Pictures produced two 15-part motion picture serials that used kryptonite as a plot device: Superman (1948) and Atom Man vs. Superman (1950).




  1. ^ Horton, Andrew; McDougal, Stuart Y.; Braudy, Leo (1998). Play it Again, Sam: Retakes on Remakes. Berkeley, California: University of California Press. p. 287. ISBN 0520205936.
  2. ^ Jones, Gerard (2004). Men Of Tomorrow: Geeks, Gangsters, and the Birth of the Comic Book. New York: Basic Books. pp. 181–183. ISBN 0465036562.
  3. ^ Hayde, Michael J. (2009). Flights of Fantasy: The Unauthorized but True Story of Radio & TV's Adventures of Superman. BearManor Media. ISBN 9781593933449.
    "Only one arc in 1943 managed to transcend its era: "The Meteor from Krypton". Debuting on June 3, it marked the debut of kryptonite..."
  4. ^ Schwartz, Julius (2000). Man of Two Worlds: My Life in Science Fiction and Comics. HarperEntertainment. ISBN 0-380-81051-4.
    pg 132-133
  5. ^ Hayde, Michael J. (2009). Flights of Fantasy: The Unauthorized but True Story of Radio & TV's Adventures of Superman. BearManor Media. ISBN 9781593933449.
    "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".
  6. ^ "Superman Homepage". Retrieved 2023-10-24.
  7. ^ Bill Finger (w), Al Pastino (p). "Superman's Return to Krypton!" Superman, vol. 1, no. 61 (November 1949). DC Comics.
  8. ^ Tippens, Norman (6 December 2000). "Dorothy Woolfolk, Superman Editor". Daily Press. WebCite. Archived from the original on 4 April 2013. Retrieved 2 October 2017.
  9. ^ Fleisher, Michael L. (2007). The Original Encyclopedia of Comic Book Heroes Volume Three: Superman. DC Comics. pp. 369–375. ISBN 978-1-4012-1389-3.
  10. ^ Greenberger, Robert; Pasko, Martin (2010). The Essential Superman Encyclopedia. Del Rey. pp. 174–177. ISBN 978-0-345-50108-0.
  11. ^ Byrne, John (w), Byrne, John (p), Kesel, Karl (i). "Bloodsport!" Superman, vol. 2, no. 4, p. 22 (April 1987). DC Comics.
  12. ^ "Superman II". Who's Who: The Definitive Directory of the DC Universe. 1 (22): 29. Dec 1986.
  13. ^ Mark Waid (w), Alex Ross (a). Kingdom Come, p. 129/4 (1997). New York: DC Comics, ISBN 1563893304.
  14. ^ Grant Morrison (w), Frank Quietly (p). All-Star Superman, no. 1 (January 2006). DC Comics.
  15. ^ John Byrne (w), Dick Giordano (p). "Games People Play" Action Comics, vol. 1, no. 600, p. 8 (May 1988). DC Comics.
  16. ^ Fleisher, Michael L. (2007). The Original Encyclopedia of Comic Book Heroes, Volume Three: Superman. DC Comics. pp. 369–375. ISBN 978-1-4012-1389-3.
  17. ^ Grant Morrison (w), Frank Quietly (p). JLA: Earth 2, p. 73/1 (September 2000). DC Comics.
  18. ^ Geoff Johns, Richard Donner (w), Adam Kubert (p). "Last Son" Action Comics Annual, vol. 1, no. 11 (July 2008). DC Comics.
  19. ^ Scharping, Nathaniel (April 4, 2018). "Space Metal Has Captivated Humanity for Ages". Discover.
  20. ^ a b "'Kryptonite' discovered in mine", BBC News, 24 Apr 2007
  21. ^ "Page Unavailable". ABC News. Archived from the original on 2011-06-29.
  22. ^ CNN
  23. ^ Washington Post
  24. ^ Staskiewicz, Keith (2 July 2015). "'Batman v Superman: Dawn of Justice': 6 EW exclusive photos". Entertainment Weekly. Retrieved 2 October 2017.
  25. ^ Storm, Ian (11 September 2005). "3 Doors Down – The Better Life (album review 4)". Sputnikmusic. Retrieved 2 October 2017.
  26. ^ "Big Boi Presents...Got Purp?, Vol. 2 – Big Boi, Purple Ribbon All-Stars". AllMusic. Retrieved 2 October 2017.
  27. ^ "Pocket Full of Kryptonite – Spin Doctors". AllMusic. Retrieved 2 October 2017.