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Marvel Cinematic Universe Wiki

"Extremis harnesses our bioelectrical potential. And it goes... here. This is essentially an empty slot, and what this tells us is that our mind, our entire DNA in fact, is destined to be upgraded."
Aldrich Killian to Pepper Potts[src]

Extremis is an advanced form of genetic manipulation created by Maya Hansen and Aldrich Killian, using nanotechnology. It grants the human body the ability to heal and regenerate from physical damages, deformities and even psychological damages. This also includes the regrowth of severed limbs in a very short timespan, various physical enhancements as well as an exothermic ability.


Used by A.I.M.

"After years dodging the President's ban on 'immoral biotech research', my think tank now has a little something in the pipeline. It's an idea we like to call Extremis."
Aldrich Killian to Pepper Potts[src]

Aldrich Killian demonstrates his powers

Extremis was created by Maya Hansen in 1999 and first tested on plants, with Tony Stark providing additional aid through a formula he deduced to help reduce the volatility. Hansen and Aldrich Killian later upgraded Extremis thanks to Advanced Idea Mechanics providing additional funding for it to begin experimental testing on human subjects. A.I.M. recruited amputees and other disabled people for the trials, most notably victims of military ops. Successful transfusions of Extremis cured their disabilities, after which they were convinced to work for A.I.M. as assassins and soldiers. However, the subjects whose bodies rejected the treatment exploded since the glitch in the code wasn't completely neutralized. At the end, most, if not all of the Extremis Soldiers, were killed by the combined forces of Tony Stark, James Rhodes, and J.A.R.V.I.S..[1]

Centipede Project

John Garrett being injected with Extremis

"Extremis. It's new. Completely unstable."
Phil Coulson[src]

Extremis was also used as the main component of a serum, designated by the Centipede Project, that combined it with Gamma Radiation, a variation of the Super Soldier Serum and the Chitauri technology for injection in an effort to create their own super soldiers.[2] The Extremis component was stabilized when Centipede recruited Chan Ho Yin, using his fireproof platelets that prevented him from being burned by his own pyrokinesis.[3] Mike Peterson, after recovering from being knocked out by the Night-Night Gun, discovered that he was now stabilized.

Shuri's Investigation

Since the Battle on the Norco and the deaths of Aldrich Killian and Maya Hansen, Princess Shuri from Wakanda began investigating Hansen's research on Extremis and grew fascinated at the concept since it successfully enabled regrowth of lost body appendages even though some of the subjects exploded. Shuri ultimately concluded that the use of Extremis still had potential.[4]

Underground Tournament

In 2024, one of the Extremis users participated in the Golden Daggers Club's underground tournament in Macau, China, hosted by Xu Xialing and Jon Jon.[5]


Maya Hansen's Extremis concept

"Disease prevention..."
"It can change the world."
"Even limb regrowth."
Maya Hansen and Tony Stark[src]

Extremis enhances the user's physiology by rewriting their DNA. It harnesses the body's bio-electricity and uses it to activate parts of the brain that govern repair and chemically recode them. This can allow Extremis to hack into the basic operating system of living organisms. If the user's body chooses to accept it, they will gain regenerative healing abilities, enabling to heal all wounds, including previously-amputated limbs or even physiological damage. When regenerating lost body parts, the wounds take on the appearance of burning embers while growing back the limb in a matter of minutes, and then cools into regular flesh, blood, and bone. Extremis also enhances physical performance, granting superhuman strength, reflexes, and overall higher resilience.

Extremis regenerating Aldrich Killian's arm

Additionally, normal Extremis users gain the ability to generate extreme amounts of heat through a complex metabolic process, with temperatures of up to several thousand degrees Celsius. Extremis users are able to consciously control the amount of heat expelled from their body, causing the area of their body generating it to glow intensely, superheating their tissues, blood vessels and nerves, while outlining them inside the body. This effect has been shown to be unstable in the event of an Extremis overload, burning the flesh and causing an explosion. Trained Extremis users can focus and conduct heat through a single area of their body such as their arms or hands, and even emit fire from their mouths, though it would seem that only the most disciplined of Extremis users can perform this feat. Certain users also demonstrated the ability to conduct heat through other objects with physical contact, allowing them to superheat targets by touching them.

Through a combination of superhuman strength and a focus of extreme heat conduction through their arms and hands, Extremis users can strike through and destroy a majority of metal structures on contact. Due to this, they are able to overpower and burn through the metal alloys that are used in most Iron Man armors, easily destroying many of the suits in combat.


Jack Taggart, about to explode from an Extremis overdose

"At this moment, the body is trying to decide whether to accept Extremis or just give up. And if it gives up, I have to say, the detonation is–it's quite spectacular. But until that point, it's really just a lot of pain."
Aldrich Killian[src]

Extremis users can be easily recognized through thermal imaging as they have a much higher heat signature. They can also be identified when their pupils glow while using their powers. Extremis does not make its users entirely invincible, as direct wounds through the chest, such as a uni-beam, will be lethal, destroying the victim's heart and therefore cutting off blood flow to the brain. When the body is regenerating, it is fragile and can be destroyed with a powerful enough force such as a repulsor shot. Destroying the users' brains and major organs through incineration has also been shown to be fatal.

The main weakness of Extremis is the possibility that its user's body will reject the serum upon initial injection, or that the serum may become unstable within the user if they fail to properly regulate their usage of it. Extremis users are able to consciously control the amount of heat expelled from their body, but this effect has been shown to be unstable in the event of an overload within. If the virus is not accepted by or regulated in the human body, the metabolic process which causes the user to generates excessive heat and the bio-electricity harnessed by Extremis will overload. As a result, the user's will rapidly build up energy and force, cumulating in a massive explosion and powerful shockwave. The resulting explosion is an excess of 3,000°C and instantly vaporizes the Extremis user's body, along with anything within a certain proximity, leaving behind shadow-like marks. A.I.M. created several terrorist attacks on United States soil to cover up the explosions caused by Extremis test subjects.


Behind the Scenes


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