Body Crystal

Body Crystal (体晶) is a drug that can be used to surpass an esper's powers, it is shown to be in a form of a fine powder that is ingested by the esper, simply licking a small amount causes significant effects. Takitsubo Rikou is a user of body clear. It is apparent that constant use of the drug makes the user unable to use their powers normally.

It was created by experiments performed by Kihara Gensei and Therestina Kihara Lifeline -- the same which created the Crystallized Esper Essence.

Sisters Arc
During team ITEM's counterattack on Misaka Mikoto, she tries to escape them, however, Mugino Shizuri hands over Body Crystal to Rikou as so she can track down Mikoto.