Wraith enzyme

From SGCommand

The Wraith enzyme is an enzyme that the Wraith inject their victims with slowly into the bloodstream throughout the feeding process. It strengthens the human body temporarily and ensures that the heart continues to beat. This is so the victim doesn't die immediately. The feeding process is so traumatic, without the enzyme, the body of the human would shut down far sooner than the Wraith would like. Simply put, the enzyme makes a victim stronger so a Wraith can take more time to kill them.

Should the feeding process be interrupted, the enzyme on its own provides the victim with incredible strength, and can even make the user resistant to Wraith stunners. The enzyme possesses narcotic properties including addiction and making users less rational. Aiden Ford became addicted to the enzyme after a Wraith that had begun to feed on him was killed after it had injected him with the enzyme but before it could start to drain his life energy, and left the Atlantis expedition to sustain his addiction. Without the enzyme, the user goes through serious withdrawal, as what happened with McKay. (ATL: "The Siege, Part 3", "The Lost Boys", "The Hive")

A type of Wraith enzyme was part of a series of daily injections given to a clone of Carson Beckett which halted the necrosis of his body. (ATL: "The Kindred")