The Vault - Fallout Wiki

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The Vault - Fallout Wiki
This page lists all addictions in Fallout 3.
  • The content is not described in full detail on this page. For details, please see the respective articles.
  • For addictions in other Fallout games, please see "Addiction".
  • For an overview of Fallout 3 content, please refer to "Portal:Fallout 3".


Alright... I got some of this pre-war stuff, should flush your system right out...

Doc Church

Unlike previous titles, addiction is permanent in Fallout 3. Each chem carries its own risk of addiction, as well as primary statistic debuffs once addicted. Chems also have what is called a "usage monitor effect," or "UMON," which is a value that accumulates with successive hits of the particular chem, raising the chance of addiction after each hit. A UMON value of 75 equates to an additional 1% chance of addiction, while a value of 175 equates to a 100% chance of becoming addicted.

Addictions can, however, be cured for a price by visiting a doctor. If the player character owns a house in either Megaton or Tenpenny Tower, the addiction can be cleared for free if the player character also owns a My First Laboratory house improvement. The healing archways in Mothership Zeta remove also addictions among their other healing effects.

Types of addiction


  • Risk is a base chance of addiction per use for alcohol only.
  • UMON is an accumulating chance of addiction for chems. See above for a detailed explanation.
  • Duration is the length of time required to pass without consuming the drug for the accumulated UMON value to be reduced.
Item Class Risk Duration UMON Withdrawal effects
Ant nectar Chems 5% 1 hour 20 -2ST
Beer Alcohol 5% N/A N/A -1AG, -1CH
Buffout Chems 10% 30 hours 30 -1EN, -1ST
Jet Chems 20% 30 hours 30 -1AG, -1CH
Med-X Chems 10% 30 hours 30 -1AG, -1IN
Mentats1 Chems 5% 30 hours 30 -1IN, -1PE
Nuka-Cola Quantum Food 10% 48 mins 12 -1CH, -15 Radiation resistance
Psycho Chems 10% 30 hours 30 -1EN, -1PE
Ultrajet Chems 20% 48 mins 12 -2AG, -1PE, -1ST
Vodka Alcohol 10% N/A N/A -1AG, -1CH
Wine Alcohol 5% N/A N/A -1AG, -1CH
Scotch Alcohol 10% N/A N/A -1AG, -1CH
Whiskey Alcohol 10% N/A N/A -1AG, -1CH

1This only applies to plain Mentats; the other variations (Berry Mentats, Orange Mentats, and Grape Mentats) are non addictive.