Heroin

Heroin is an opiate derived from morphine. It is typically injected intraveniously so as to "get high" and reach euphoria. Side effects include: nausea, vomiting, constapation, the inability of urinate, skin rashs, lowered heart rate, shallow breathing, coma, seizure and even death.

Prior to Day 3
While undercover with the Salazars, Jack began using heroin to blend in with the drug cartel.

Day 3 and beyond
During the events of Day 3, Jack battled his heroin addiction. It was eventually used as a scapegoat for his termination by Erin Driscoll.