Med-X

Med-X is a chem that appears in Fallout 3, Fallout: New Vegas and Fallout 4.

Background
Med-X is a potent opiate analgesic that binds to opioid receptors in the brain and central nervous system, reducing the perception of pain as well as the emotional response to pain. Essentially, it is a painkiller delivered by a hypodermic needle. According to the Powder Ganger, Boxcars, five hits of Med-X is enough for a man to "put himself out of his misery," though he also claims that if the Courier wanted him dead, fifteen doses of Med-X would make him overdose. With enough Medicine skill when talking with Joana, it is revealed that Med-X addiction includes such sympthoms as contracted pupils and involuntary spasms.

Med-X
Med-X is a potent pain killer that can often be found in first aid boxes or abandoned medical facilities. This chem will increase damage resistance by 25%, but it also carries a 10% addiction rate, and withdrawal results in a -1 penalty to Agility and Intelligence.

Behind the scenes
Med-X was originally to be named morphine in Fallout 3, but this resulted in the Australian Classification Board refusing its classification and thereby making it illegal to distribute the game in Australia. The game was later censored to remove all real-world drug references including changing morphine to Med-X in order for the game to be allowed in Australia. This censorship was to become part of the worldwide release.