Chemical X is a powerful, mutagenic chemical that gives people and animals superpowers and special abilities. Professor Utonium seems to own an unlimited supply of it in his lab. The chemical was an accidental extra ingredient in the Professor's concoction for perfect little girls thanks to an accident caused by Jojo, the Professor's monkey. This led to the creation of the Powerpuff Girls, and the explosion turned Jojo into Mojo Jojo. Since then the chemical has been used in numerous episodes, usually to give superpowers to people and animals. Mojo Jojo himself uses it to turn other primates evil and intelligent in his image, with oversized brains, green skin, pink eyes and the ability to speak. The chemical is also responsible for giving the Girls their distinctive appearance, as seen in "Oops, I Did It Again".
The Chemical's appearance is a viscous black liquid similar to oil, and is usually contained in a round glass bottle with a cork on it, though in the episodes "Mo Job" and "Twisted Sister" it appeared as glowing light blue liquid. It is also in a powder form, as seen in "Toast of the Town". Despite being an important plot point in some episodes, very little is actually known of the chemical itself, such as how it is made or whether or not it naturally occurs.
According to Professor Utonium in Mizzen in Action, Chemical X was designed to work with other ingredients to provide balancing components to the power yield in quantity embedded. Therefore when Pure Strain Chemical X is ingested and overloaded without other ingredients in a given subject, it lacks the absorbing factors to make the powers given to the subject permanent, thus allowing its effects to eventually wear off and physically exhaust its consumer.
The effects of Chemical X can be erased by Antidote X, which has been synthesized on many occasions, but it seems as though Chemical X can be re-used on the same subject multiple times. However, as seen in "Knock It Off", it is possible to destroy the Powerpuff Girls by forcibly extracting the Chemical X from their bodies, but they can still be revived with love.
Originally, a can of Whoopass (thus the name Whoopass Stew) was the extra ingredient, but during the making of the series, it was replaced with Chemical X due to FCC regulations regarding swear words in a children's cartoon.
Antidote X, as its name implies, is an antidote to Chemical X. It is a thick, red liquid (though it's black in the movie) that takes away powers given by Chemical X. It first appears in Mo Job where Mojo Jojo successfully synthesizes it for use in a plot financially backed by Princess Morbucks, and according to the events of the movie, the Professor is first to synthesize it for use on the girls (though Mojo Jojo is dosed with it upon his defeat). It is implied by the Professor that it is cherry-flavored.
Beings Created\Given Powers from Chemical X
- The Powerpuff Girls
- Mojo Jojo (he was mutated by it)
- The Rowdyruff Boys
- Bullet (a small dose administered by Bubbles)
- Methane Monster
- The Gangreen Gang: Had temporary superpowers from Chemical X when the girl's eye beams made chemical reactions with candy and snacks happen in their stomachs in the episode, "Power Lunch."
- Princess Morbucks: Was also given powers from Chemical X when she teamed up with Mojo to try and destroy the girls in the episode, "Mo Job," though they were taken away when Princess was hit with Antidote X in the same episode.
- The Mayor of Townsville: Used powder Chemical X to try and give himself hair in Toast of the Town; it worked, though it had the side-effect of making the Mayor grow giant. Eventually, the Powerpuff Girls reverted him back to normal with toast topped with Antidote X jelly.
- Mojo Jojo: Given (additional) powers twice. In "The Powerpuff Girls Movie" he uses it to grow huge and in "Mr. Mojo's Rising" he gains powers identical to the Powerpuff Girls.
- Pirates: In "Mizzen in Action" several pirates and their ship are given powers.
- Dick Hardly: After drinking Chemical X he mutates into a large monster. According to the rules established in "Mizzen in Action" this change would have been temporary.
- Children: In the episode "Mojo Jonesin'", four children are given a limited supply of Chemical X by Mojo Jojo, who later tricks them into defeating the Powerpuffs. Their powers simply wore away, but whatever was left of them were used to restore the girls.
Chemical Z is a mutated form of Chemical X in Demashita! Powerpuff Girls Z. It was created when Poochi accidentally dropped a Zuber Cake into the vat of Chemical X. What's inside this can is something mysterious.