Mirakuru (ミラクル, lit. as Miracle) is a serum that gives strength of ten men and heightened speed, endurance, durability, agility, stamina, and reflexes when injected. Though it can cause death.
Its exact effects and are unclear, though so far every individual injected with the serum has suffered convulsions and begun bleeding from the eyes immediately after injection. If the subjects survives, they awaken after a few hours with the serum in full effect with strength, endurance, durability, and speed increased to superhuman levels; in addition, to a healing factor. The Mirakuru also enhances the user's senses as Slade was able to smell the TNT that was planted in attempt to kill him. In order for the serum to work properly, a sedative must be administered along with it, otherwise the recipient will die. However, in some cases a subject can survive the Mirakuru injection without the sedative, as demonstrated with Slade Wilson and Roy Harper. Human blood is also apparently a component required to either manufacture the serum or to use it properly.
According to Sara Lance, the serum has serious side effects even on those who survive injection, either deforming their bodies or warping their minds. A person can keep themselves from completely losing their control with intense focus.
According to Anthony Ivo in "Keep Your Enemies Closer", the Mirakuru was a serum that caused increased strength and rapid cell regeneration created by the Japanese during World War II in hopes of creating an army of super soldiers. They transported their only supply through submarine, and when it was under heavy fire by the Allied Forces, it ran aground on Lian Yu. After the men of Ivo invade the island, they were slaughtered by Oliver, Shado and Slade. Because the picture they have, he managed to set the cave seeking. In the cave, they found a number of bodies of Japanese World War II, all with deformed skulls. Next to the body was a Hozen with scriptures. Some time later, Oliver was kidnapped by Ivo, and forced to take him to the Hozen. After an ambush, Oliver and Sara are rescued by both, and they discover a series of coordinated proceedings of the stone. When they reached the abandoned submarine, he found a box with several injections containing Mirakuru, amid so they inject in Slade, who was dying, due to previous injury, even without the necessary anesthetic. After Slade apparently dying, the men of Ivo, find the submarine and collect the serum, as well as lead Oliver, Sara, and Shado as hostages. Hours later, Slade awakens, his wounds healed completely, and with all-powerful abilities. After running up to Oliver and others, Slade uses his abilities to kill all of Ivo's men.
Sometime later, Ivo tested the serum in several men, however all died. Oliver also managed to recover the remaining samples, and burned them. Slade later offer his blood to mass produce the Mirakuru to Sebastian Blood, who used it to create an army of superhumans. Unlike Oliver and Slade's relationship, Sebastian is somehow able to maintain control over men he injected with the Mirakuru.
In "Crucible", Xavier Reed is captured by Blood and injected with Mirakuru; he dies after bleeding from his eyes, unable to control or resist the affects. Also, Sin's friend, Max Stanton was found in an alley, dead with blood running out of his eyes, revealing that he was injected with the serum, but was unsuccessful and died.
In "The Scientist", Gold is shown to have super strength and superhuman durability, as implied by the drug's assumed effects. Furthermore, while he defeats Oliver twice, Oliver claims he has beat at least one user of Mirakuru on Lian Yu. He also states that all of Ivo's test subjects are dead, and that he burned the rest of the serum that they found on the Japanese submarine.
In "Three Ghosts", it is shown that Sebastian Blood recreated Mirakuru using samples from Slade Wilson's blood. Also, Brother Blood forcefully injects Roy Harper with the serum, causing his eyes to bleed until he dies. Oliver though is convinced by a hallucination of Tommy Merlyn to keep fighting and he manages to kill Gold by blowing up the centrifuge, spilling chemicals all over him. Oliver then manages to revive Roy. Later, while resting, Roy discovers that the wound on his knee from where Arrow shot him is completely healed.
In "The Promise", Sara and Oliver burn the box that the Mirakuru belonged in, believing the Mirakuru to be inside it, it is later revealed that Slade hid it, and kept it on him in case he needed it.
In "Deathstroke", during a meeting with Slade Wilson and Sebastian Blood, Isabel Rochev explains that since taking full control of Queen Consolidated she has devoted all resources of Queen Consolidated's applied sciences division to mass-producing the Mirakuru.
In "The Man Under the Hood", Team Arrow blows up Queen Consolidated's applied sciences division, forcing Slade to find an alternative means of administering Mirakuru to his army of prisoners. He captures Roy and steals a "bio-transfuser" from S.T.A.R. Labs and uses it to transfuse the Mirakuru from Roy's blood into the prisoners. The Arrow interrupts the process and rescues Roy, but Slade manages to use his own blood to successfully infuse Isabel Rochev and the prisoners with Mirakuru.
During the island flashbacks, Ivo reveals that he created a cure that could reverse the effects of the Mirakuru. In the present day, Oliver steals a sample of Mirakuru from Slade and gives it to Felicity, who asks Cisco Ramon and Caitlin Snow to help her analyze it and synthesize the cure.
- "Keep Your Enemies Closer"
- "State v. Queen"
- "The Scientist"
- "Three Ghosts"
- "The Promise"
- "The Man Under the Hood"
- Cyrus Gold (successful; deceased)
- Xavier Reed (unsuccessful; deceased)
- Slade Wilson (used to heal injuries; successful)
- Roy Harper (unwillingly; successful)
- Max Stanton (unsuccessful; deceased)
- Isabel Rochev (successful)
- Japanese Soldiers (successful; all deceased)
- Prisoners (successful)
- Deathstroke, in the comics was injected with a experimental serum by the US government which left him in a coma for months. When he awoke the serum had enhanced his body giving him the strength of ten men along with heightened speed, agility, stamina, and reflexes. It also increased his capacity to use up to 90% of his brain at any one time. The serum also provided him with a healing factor in his blood that enabled him to heal from physical injury much faster than a normal person; however, it did have limitations, as he could not heal his missing eye and cannot regenerate entire limbs.
- Mirakuru is similar to other drugs used in DC comics such as Venom, a steroidal compound used by Bane to enhance his strength. Venom was derived from Miraclo, a serum used by the hero Hourman which lasted only one hour. Another serum used in the comics was Blockbuster, which permanently enhanced Mark Desmond and his brother Roland Desmond into hulk like monsters.