Teardrops

Teardrops (commonly known as "drops") are concentrated pieces of mana used as medicine on Ravnica.

Applying one to a wound causes it to heal quickly as the mana dilutes. They are used primarily for quick cures, as they can be dangerous with use over the course of years. Eventually, the shock of raw mana in your blood can become lethal if you willingly expose yourself to it too much. A teardrop can eventually become less like a medicine and more like a suicide pill.