Psycho

Psycho is a highly potent psychosis-inducing amphetamine in the Fallout games. It has been described to increase tolerance to pain and causes extreme anger and recklessness.

Background
 Psycho appears in the form of an extremely potent injectable amphetamine composed of strange, unknown chemicals of military origin which comes with its own unique delivery system. It was designed at the orders of General Chase specifically for military use. It increased a soldier's damage resistance, and its dampening effect on higher brain functions made for tough—but uncontrollable-troops. This drug was very popular for human-wave assaults. 

Psycho


Depending on the game, Psycho will give different effects. In Fallout and Fallout 2, Psycho increases damage resistance, allowing users to survive more hits in combat. In Fallout 3 and Fallout: New Vegas, Psycho increases the damage dealt. In the latter game, Psycho is an ingredient for the Slasher drug. In Fallout 4, Psycho acts like Slasher did in Fallout: New Vegas, boosting damage resistance as well as the Sole Survivor's damage output.

Slasher


Slasher is a chem which combines the effects of Med-X and Psycho into a single consumable. It is possible to combine the effects of Slasher with Med-X to gain a 50% total boost to damage resistance. It does not stack with Psycho.

Psychojet


Psychojet, like Slasher, combines two chems, Psycho and jet. Psychojet increases damage resistance and slows time for ten seconds.

Psychobuff


Psychobuff is a combination of Psycho and Buffout which gives increases to Endurance, Strength, maximum health, and damage dealt.

Psychotats


Psychotats is a combination of Psycho and Mentats which gives an increase to Perception, as well as damage resistance.