- "Made of low-grade Kryptonite. Radioactive mineral from your home planet. It weakens you."
- —Hank Henshaw to Supergirl[src]
- 1 Overview
- 2 History
- 3 Known users
- 4 Appearances
- 5 Behind the scenes
- 6 References
- "I've never seen anything like it. It's definitely not from this planet. It seems to be emitting a specific radioactivity that's damaging to your cellular structure."
- —Astra's associate[src]
Kryptonite is normally green, and Kryptonians exposed to the element will become weak within close proximity to it or if pierced by weapons laced with or made from the substance, and prolonged exposure is fatal. Kryptonite is comprised of sodium, lithium and boron, as well as elements not found on Earth. Kryptonite's effects are radioactive in nature and therefore cannot penetrate the element lead. The radiation of the mineral can be harnessed and used independent of the mineral itself to harm a Kryptonian; usually appearing in the form of artificial light emitted from certain machinery. It has even been used as anesthesia or a sedative against Kryptonians due to its affects. Kryptonite inside the body causes green glowing veins to protrude from the skin of the Kryptonian and the physical pain it causes becomes unbearable at that point. Physical signs of being affected by Kryptonite are somewhat fever-like, including nausea, weakness, dizziness, vertigo, fatigue, pain and loss (or near loss) of consciousness. Physical contact with Kryptonite of higher intensity is enough to cause burning pain. Kara described the Kryptonite poisoning as like having "nails in [her] blood".
Although simply being around green Kryptonite doesn't adversely affect humans the way it does Kryptonians, having it shot directly into the body can still cause terminal radiation poisoning.
A short time after J'onn J'onzz (posing as Hank Henshaw) assumed leadership of the D.E.O., the organization received reports of an asteroid that had just landed in the desert. Since Superman occasionally worked with D.E.O. at that time, he accompanied J'onn to investigate. Upon arrival, in the darkness, J'onn saw something glowing emerald-green in the crater. While J'onn was unaffected by it, being near it severely weakened Superman. This led J'onn to name the substance "Kryptonite". Because of the threat it posed, Superman wanted to destroy it, but J'onn kept it to use as a weapon against other hostile Kryptonians. This led to a falling out between the two that wouldn't be mended until several years later when J'onn entrusted all of the D.E.O.'s Kryptonite to Superman to get rid of in order to keep it out of the wrong hands.
At some point after declaring his war on Superman, Lex Luthor created a device designed to release kryptonite into a planet's atmosphere, thus making that entire planet uninhabitable to Kryptonians.
Alex Danvers taught Kara to fight in a room lined with low-intensity Kryptonite emitters, just enough for Kara to be brought down to normal strength. In the field, Alex utilized a sword made from Kryptonite and it was ultimately used to kill Astra.
During the Daxamites' invasion of Earth, on Lillian Luthor's urging, Winn and Lena modified a version of Lex's kryptonite bomb to disperse lead into the atmosphere as a stoppage measure to force the Daxamite army to leave Earth. Lena entrusted the device's remote to Kara so that only the latter would be able to activate the device. When Rhea refused to withdraw her forces even after being overpowered in a fight against Supergirl, Kara reluctantly activated the device; killing Rhea and forcing the army to retreat. Sadly for Kara, this also forced her boyfriend, Mon-El, to leave the planet.
At some point after meeting Earth-38's Supergirl, Oliver Queen of Earth-1 came into possession of arrows with heads made of green kryptonite in case he ever met an evil version of his Kryptonian friend. He then used these arrows in battle against Kara's Nazi doppelgänger from Earth-X.
A little over a year later, a version of Lex's device was used by the Children of Liberty to pump Kryptonite into Earth's atmosphere, though, on Alex's urging, Lena was able to put Kara in a special suit designed to protect the latter against kryptonite, which Kara then wore until they could make the planet's air safe for her again. After special nanites built by Brainy and Lena devoured the kryptonite in the atmosphere, Kara was able to remove the suit. though she later donned it again to protect herself from kryptonite weapons utilized by Lex Luthor.
About a year later, Barry Allen (who, as a result of an alteration of Earth-1's reality, had gained Oliver's skills as an archer and martial artist) and Oliver used Kryptonite arrows to battle A.M.A.Z.O. and John Deegan, respectively.
At some point after Superman arrived on Earth in Earth-99's universe, that Earth's Bruce Wayne started keeping a stash of Kryptonite in his lair, and wound up murdering the Kryptonian. After Bruce was accidentally killed by Earth-1's Kate Kane (who'd been protecting Earth-38's Supergirl from Bruce), Kate stole some of Bruce's Kryptonite. When Kate told Kara about it a short time later, the latter told Kate to keep it; trusting her to not use it.
On Earth-Prime, Lucius Fox stated in his journal that Green Kryptonite is the only thing capable of penetrating the Batsuit. Alice later read the journal and learned that it can cut through anything. At some point, Professor M. Darby analyzed a sample of Kryptonite, although he did not know its true name; just that it was a "rare meteor rock," learning of its cutting power.
The Earth-Prime version of the D.E.O. kept large deposits of green Kryptonite until it was stolen by Rama Khan, to be used to kill Kara, requiring her to have an Anti-Kryptonite suit created by Lena Luthor.
After Tommy Elliot (posing as Bruce Wayne) took Kate's shard of Kryptonite from Luke Fox, he loaded the Kryptonite fragment into a gun, proceeding to shoot Ryan Wilder (who had stolen the Batsuit after finding it in the wreckage of the plane crash that supposedly killed Kate with Tommy now wanting the suit so he could pose as Batman). True to Lucius Fox's journal, the Kryptonite went straight through the suit's armor and pierced Ryan's skin, leaving her injured and knocking her to the ground.
- "Kryptonite is comprised of sodium, lithium, boron, and elements not found on Earth. As a result, this makes it the singular material that can penetrate the Batsuit, and the only failsafe that protects the suit against corruption."
- —Ryan Wilder reads up on kryptonite[src]
While Ryan did survive (returned the Kryptonite and the Batsuit to Luke) she, after examining her shallow wound a short time later, found that the Kryptonite, even though the stone had been removed from her cut, seemed to be affecting her in a strange way; causing green veins to spread outwards from the ballistic trauma, with the wound only getting worse over time. Eventually, it got so bad that in addition to the intense pain that the wound continued causing her, she also began experiencing episodes of severe vertigo and photopsia; prompting her to do more research on the stone's properties.
The blue, molecular opposite of Green Kryptonite was created by Alex Danvers at the D.E.O. by reversing the ionic charge of Green Kryptonite. While Blue Kryptonite has no effect on Kryptonians, it severely weakened Bizarro and sedated her, allowing her to be captured. It also seemed to have a calming effect on Bizarro, removing her rage toward Supergirl and allowing her to think rationally.
Maxwell Lord created a synthetic red form of kryptonite in hopes of subduing Non's next attack. However, it didn't work as intended; rather than weaken Kryptonians physically, red kryptonite alters their minds by weakening and gradually destroying their inhibitions, as well as bringing out every negative thought to the surface. They can even feel its effects long after they have left its presence. As this happens, red, glowing veins momentarily protrude from the skin when they first come near red kryptonite and subsequently in times when the victim's actions and thoughts are most affected by the substance. Symptoms of red kryptonite infection first start as the Kryptonian becoming more abrasive and immature in personality and actions as their mental and emotional restraint is lessened. Eventually, the Kryptonian will be left without morality, patience, rationality or any cares, whatsoever. They can even develop narcissistic tendencies and arrogance that results in an inferiority complex. After having expressed their negative personality traits fully, the Kryptonian will become malevolent and prone to hostility and aggression, leaving them a danger to everyone around them. However, Maxwell also developed a cure for it in the form of a red energy beam gun that neutralized the red kryptonite at a targeted victim and knocked them out, as the substance left Kara's body in the form of a red gas. This ultimately returned Kara to her normal self.
A silver colored form of Kryptonite that was found and used by Queen Rhea from the vast quantities of Kryptonite that rained down on planet Daxam. This kryptonite will cause a Kryptonian to fall in a deep and frightful hallucination where nothing from the outside world will stir them out of it until it leaves their system. When Superman confronted Rhea, she poisoned him with it and he was convinced that Supergirl was actually his greatest enemy Zod who had come back to destroy everything he loved. While under the effects of Silver Kryptonite, Superman was unable to hear Kara but only hear Zod talking. Unlike green kryptonite, silver kryptonite will not weaken or dampen a Kryptonian's powers at all. When in vast quantities, it will reveal itself as glowing silver veins on the Kryptonian's skin.
After J'onn J'onzz gave all of the D.E.O.'s remaining green kryptonite to Superman to destroy it, preventing Cadmus from further using green kryptonite against him and Kara, Cadmus was forced to create their own artificial version of green kryptonite. While this synthetic kryptonite does have the same effects on Kryptonians as natural green kryptonite, as well as serving as the source of Metallo's powers, it was proven to be too unstable, as it eventually exploded; killing Metallo in the process while also releasing a large cloud of Kryptonite gas, although Kara was able to avoid contact with it.
Lena Luthor was able to create an extremely stable synthetic version of green kryptonite (which wouldn't explode; a feat that even Cadmus could not achieve) which, after learning of Samantha Arias's Worldkiller persona, she began using to contain Sam at L-Corp and (consensually) run tests on the latter in an effort to find a way to get rid of Reign (though, when questioned by the D.E.O. on the matter, she claimed it was a stash of kryptonite Lex had kept in a vault in the lab, but later confided in James Olsen that she'd figured out how to make the kryptonite; it hadn't been Lex's). After obtaining a sample of Harun-El, she was able to figure out how to make more of that type of Kryptonite as well.
On their home world or in Argo City, Black Kryptonite is harmless to Kryptonians. However, on Earth, touching the substance not only causes great pain to a Kryptonian, but also makes their powers unstable. It can also be used to split a Kryptonian into two separate entities (such as when Lena used it to separate Reign from Sam; one of the evil, the other good). When Kara used it to send herself, Reign and Sam into the Dark Valley to defeat Reign anyone else getting hurt, it split Kara in two; sending her duplicate to Kaznia, unbeknownst to Kara at the time.
Harun-El is also an incredible power source. It was able to power the dome of Argo City as well as sustain an ecosystem and the artificial gravity on the asteroid that houses Argo. Argonians were given a recipe to make the substance from elements on Argo, courtesy of Lena Luthor who figured out how to make it. When harnessed correctly, black kryptonite has mutagenic and healing properties on humans. Hearts that Lena has tested with a serum using black kryptonite had unintentionally been made invulnerable. After being perfected, the serum was used on James Olsen and Lex Luthor to heal them both. The version used on James was supposedly separated from the mutagenic part, but this wasn't successful and he gained temporary Kryptonian powers; including enhanced strength, enhanced senses, flight and heat vision, until the drug was extracted from his body. Lex Luthor and Ben Lockwood at least gained the power of super strength while the Harun-El was in their systems, though both later had the drug forcibly taken out of their bodies.
- Lex Luthor: At some point after Lex started targeting Superman, he discovered Kryptonite could be used as a weakness for Kryptonians and used it for many schemes, including going so far as to inject himself with Kryptonite in order to keep Superman away from him and ordering Eve Teschmacher to perform the "Metallo Procedure" on Otis Graves thereby reviving him as a Kryptonite-powered cyborg. Kryptonite powered his Lexosuit, which was used in his meeting with Red Daughter and battles with Supergirl. During the Anti-Monitor Crisis, Lex attempted to use a piece of Kryptonite against Clark Kent of Earth-167, but because Clark had given up his powers, it had no effect and Clark snatched it out of his hand and threw it into a field.
- Maxwell Lord: Max created Red Kryptonite in hopes of stopping Non's army; unfortunately, Kara inadvertently came in contact with it. The Red Kryptonite lowered and gradually destroyed her inhibitions and turned her into a corrupt version of herself.
- Lena Luthor: Lena revealed that she was able to create Green Kryptonite, Lena used the Green Kryptonite to contain Samantha Arias and run tests on her, to try and get rid of Reign.
- Kate Kane: Kate had stolen a small amount of Kryptonite from the Bruce Wayne of Earth-99 after he tried to kill Kara Danvers. However, Kara allowed Kate to keep it, hoping she wouldn't have to use it.
- Leviathan: Rama Khan stole the stash of Kryptonite once held by the D.E.O. and gave rings to Sela and Tezumak so they could fill them with radiation to kill Supergirl. However, the majority of Leviathan's supply of the substance is stored in their headquarters.
- D.E.O.: Green Kryptonite was used by the members of the D.E.O., who utilize it against those that hail from the planet Krypton. They utilize it in the form of restraints and certain weapons, such as blades, darts, and bullets. Prison cells designed for Kryptonians, as well as training rooms, have Kryptonite lights that can be lowered to simply de-power a Green Kryptonian, while higher levels can incapacitate, cripple, and nearly kill them. However, after it was discovered that the D.E.O. had a spy from Project Cadmus who stole the Green Kryptonite from their organization; J'onn J'onzz gave all of the D.E.O.'s remaining Kryptonite to Superman to destroy it.
- Project Cadmus: Cadmus created a synthetic version of the Green Kryptonite that had the same effects as natural green kryptonite. It was used to power their Green Kryptonite-powered cyborg Metallo. However, the synthetic version proved too unstable and eventually exploded. They also used natural green kryptonite, that was used to power their second green Kryptonite-powered cyborg Metallo, however, once the D.E.O. discovered that they had a spy from Cadmus in the organization; J'onn J'onzz gave all of the D.E.O.'s remaining green kryptonite to Clark Kent (under the guise of Superman) to destroy it; preventing Cadmus from further using green Kryptonite against Clark and Kara.
- Rhea: Rhea had Kryptonite weapons forged from the massive amounts of Kryptonite that rained down on Daxam after Krypton was destroyed and ravaged her home world. She later used another form of Kryptonite, Silver, on Superman to make him hallucinate and fight Supergirl, with Superman believing he was battling Zod. Being dead now, most of her Kryptonite has been destroyed. Rhea also had Kryptonite infused in her blood incase she was ever in a fight with Supergirl or Superman, she could easily weaken them and gain an advantage.
- "Is that a Kryptonite arrow? Why do you have a Kryptonite arrow?"
- "In case an evil you ever showed up!"
- —Kara Danvers and Oliver Queen[src]
- Oliver Queen: Oliver possessed arrows with tips made out of Green Kryptonite on the chance that an evil Supergirl would show up. It is unknown how he gained the Kryptonite but it is possible that the Krypton of Earth-1 was destroyed as well, allowing the Kryptonite produced from the explosion to make its way to Earth, where Oliver found it and deduced what it was.
- Barry Allen: When reality was altered by John Deegan, Barry became Green Arrow and thus had Kryptonite arrows just like Oliver. He then used them against A.M.A.Z.O..
- Bruce Wayne: When Superman arrived on Earth-99, Bruce had discovered Kryptonite and used it to kill the Kryptonian. He attempted to use a piece of Kryptonite on his exosuit on Kara Danvers, but was killed before he could kill her. Kate Kane then collected the Kryptonite in his possession.
- Bruce Wayne: Bruce Wayne had some Kryptonite stored in the Batcave. According to Lucius Fox's journal, the substance is one the few things capable of penetrating the Batsuit. For Batwoman's safety, Luke Fox subsequently destroyed the sample of Kryptonite Bruce had kept.
- Luthor: In his first battle with the Superman on Earth-Prime, Luthor used a retractable blade made of Kryptonite to stab Superman; but lost it once he pulled it out.
Superman & Lois
Behind the scenes
- Green Kryptonite: Green Kryptonite can weaken a Kryptonian's physical attributes, however, the radiation effects of Green Kryptonite are harmful to humans given sufficient long-term exposure, resulting in cancer.
- Red Kryptonite: Like Green Kryptonite, Red Kryptonite can weaken a Kryptonian's physical attributes; but to a greater degree. It's exact effects are often unpredictable; yielding different results every time a Kryptonian is exposed to it.
- Anti-Kryptonite: Anti-Kryptonite is harmless to Kryptonians; but has the same effect as the green variety on normal humans.
- X-Kryptonite: X-Kryptonite is harmless to Kryptonians; but it gives normal life-forms superhuman powers.
- Blue Kryptonite: Blue Kryptonite can affect Bizarro in the same way the green variety of Kryptonite affects Kryptonians; Blue Kryptonite is the antidote to the random and bizarre effects of Red Kryptonite. Generally it is harmless to real Kryptonians. However, in some continuities, it can strengthen the normal physiology of Kryptonians or even heal their wounds.
- White Kryptonite: White Kryptonite can kill all plant life, from any world.
- Red-Green Kryptonite: Red-Green Kryptonite can cause Superman to mutate, temporarily growing a third eye in the back of his head.
- Gold Kryptonite: Gold Kryptonite can remove a Kryptonians' ability to process yellow sunlight; this version of Kryptonite only removes a Kryptonian's powers temporarily, but enough exposure can render them powerless forever.
- Red-Green-Blue-Gold Kryptonite: Red-Green-Blue-Gold Kryptonite can enhance the intelligence of a Kryptonian.
- Silver Kryptonite: Silver Kryptonite can causes Kryptonians to suffer from altered perceptions, loss of inhibition and extreme hunger cravings.
- Jewel Kryptonite: Jewel Kryptonite allows the wielder to project illusions or perform mind control.
- Bizarro-Red Kryptonite: Bizarro-Red Kryptonite affects normal humans the same manner that Red Kryptonite affects Kryptonians.
- Red-Gold Kryptonite: Red-Gold Kryptonite temporarily deprives Kryptonians of their memories.
- Magno-Kryptonite: Magno-Kryptonite is magnetically attracted to all substances originally from Krypton.
- Red-Green-Gold Kryptonite: Red-Green-Gold Kryptonite can permanently remove the individual's powers and memories of ever having been Superman.
- Slow Kryptonite: Slow Kryptonite affects normal humans in a manner similar to Green Kryptonite.
- Kryptonite-X: Kryptonite-X can supercharge a Kryptonian and restore their ability to process solar radiation.
- Pink Kryptonite: Pink Kryptonite turns Kryptonians lesbian, gay, bisexual or transgender.
- Black Kryptonite: Black Kryptonite can split a Kryptonian into two separate entities; one good and the other evil.
- Orange Kryptonite: Orange Kryptonite gives superpowers to any animal that comes into contact with it for 24 hours.
- Periwinkle Kryptonite: Periwinkle Kryptonite causes Kryptonians to lose all inhibitions.
- Platinum Kryptonite: Platinum Kryptonite permanently grants all of the powers of a Kryptonian to ordinary humans.
In live-action media, the most common form of Kryptonite seen is green Kryptonite. The effects are generally the same in all live-action versions. It weakens a Kryptonian's physical attributes, including blocking the ability of the body's cells to absorb and use yellow solar radiation with continued exposure. Green K can kill with prolonged exposure.
Other types of Kryptonite have also appeared.
In Superman III:
- Synthetic Kryptonite: Artificially created Kryptonite that substitutes cigarette "tar" in place of an unknown component of true Kryptonite. Intended to harm and kill Superman, the flawed Kryponite initially corrupts Superman, then splits him into two personas: a belligerent, selfish, and careless Superman; and good, kindhearted, mild-mannered Clark Kent. The two fight and when Clark wins, the personas merge and Superman returns to normal.
On The Adventures of Superboy:
- Red Kryptonite: Man-made form of Kryptonite created while trying to neutralize the effects of green Kryptonite so it could be used as an alternative power source. Superboy turned evil with a single exposure; a second exposure reversed the effects.
- White Kryptonite: Unlike its comic counterpart, white Kryptonite was created by using the same duplicating ray that made Bizarro in an attempt to form a Kryptonite to kill Bizarro. Instead, the white K stabilized and cured the molecularly unstable Bizarro.
On Lois & Clark: The New Adventures of Superman:
- Red Kryptonite: Clark Kent was shown to suffer differing effects when exposed to red K at different times, including apathy, uncontrollable increase of his powers, a sense of apathy, and a transfer of his powers to Lois Lane.
- "Hybrid" Kryptonite: A man-made form created by a renegade S.T.A.R. Labs scientist. Harmless to Kryptonians; caused the same effect on humans as green Kryptonite on Kryptonians.
In Superman Returns:
- Green Kryptonite: Lex Luthor combined green K with Kryptonian crystalline technology to create a new continent off the coast of Metropolis that threatened to destroy North America.
- Green Kryptonite: Aside weakening and harming Kryptonians (and suppressing their powers, especially their healing factor and invulnerability), can, under cretain circumstances, to caused mutations in humans, animals, and plants. Humans developed a variety of superhuman abilities that typically proved dangerous to themselves and others. In some cases, the radioactivity of green K could be neutralized and the resulting "clear" kryptonite would be harmless to Kryptonians and humans.
- Red Kryptonite: Continuous contact with red K compromised a Kryptonian's inhibitions and morality, often causing them to break the law and act selfish and rebellious. The effect on humans is mostly unknown, though seemly have no effect unless is combined with some chemicals. Removing the contact quickly ended the effects.
- Black Kryptonite: Could separate aspects of the psyche of Kryptonians or humans and manifest them in a duplicate body, typically as "good" and "bad" versions of someone. Black K was created by superheating green kryptonite to extremely high temperatures.
- Silver Kryptonite: An artificial Kryptonite infused with silver shards created by the liquid metallic form of Brainiac. The silver induced hallucinations and paranoia in Kryptonians. It also suppressed their general invulnerability, allowing them to be cut so the silver could enter the bloodstream.
- Blue Kryptonite: Suppressed superhuman abilities in Kryptonians with continuous contact, specifically resistance to illness and injury. Aging in Kryptonians was also increased to the speed of humans by prolonged contact. Kryptonians were resistant to effects of green kryptonite when in contact with blue K. In humans, blue K dramatically improved health. With Bizarro, blue K exponentially increased the clone's powers to the point the body became unstable and exploded, killing the Phantom Zone wraith. It also removes a Kryptonian's powers, but only as long as the Kryptonian remains in contact with it.
- Gemstone Kryptonite: A mineral infused with Kryptonite that would give Kryptonians the power of hypnotic persuasion over others. It was primarily seen in pulverized dust form. The persuasion could also affect the Kryptonian persuader if their command was directed back at them through a reflective surface. The effects were counteracted with green K.
- Gold Kryptonite: While heated up, can be used to permanently scar Kryptonians. Prolonged contact could permanently remove all Kryptonian superhuman abilities. Contact with a large amount of gold K could kill a Kryptonian.