With the Chemist perk, any chems you take last twice as long.

— In-game description

Chemist is a Fallout 3, Fallout: New Vegas and Fallout 4 perk.

Fallout 3Edit


This perk doubles the active time for chems.

List of itemsEdit

The following items will work with this perk.


  • This perk synergizes well with the Chem Resistant perk, the latter providing a 50% resistance against addiction.
  • Chemist affects any item which also influences the Chems Taken statistic.
  • Though it specifically states that chems will last twice as long, it affects anything you can get addicted to, including alcohol.

Fallout: New VegasEdit

List of itemsEdit


  • In Hardcore mode, all positive effects (including foods, medicines, chems...) are also affected by this perk, for example: gecko steak, RadAway, stimpak, purified water, ....etc.
  • Synergizes well with Chem Resistant, Fast Times, Day Tripper, Whiskey Rose and a high Survival skill.
  • If you have both Chemist and Day Tripper, all consumable foods have their times increased. For example, the effects of brahmin meat normally last for 15 seconds; with these two perks it increases the duration up to 40 seconds. This is likely due to the game engine defining a chem as anything that can "wear off", which food does in the game.
  • The increased duration of healing items does not show up in the list of effects for the items on the Pip-Boy.
  • This perk also affects Stealth Boys, making them last 4 minutes. Combined with Stealth Girl, they can last over 8 minutes.

Fallout 4Edit

Any chems you take last 50% longer. Far out.

— Rank 1 description

In addition to the Chemist perk affecting the duration of chems, ranks in Chemist are needed to unlock some recipes at the chemistry station usable in settlements.


Rank Requirements Description Base ID
1 INT 7 Any chems you take last 50% longer. Far out. 000e36ff
2 INT 7, LVL 16 Any chems you take now last twice as long. 000e3700
3 INT 5*, LVL 32 Any chems you take now last an additional 150% longer. 000e3701
4 INT 5*, LVL 45 Any chems you take now last an additional 200% longer. 001d2458

* 3rd and 4th ranks require 5 Intelligence as opposed to 7 due to a bug.


  • Your Pip-Boy will show the enhanced duration of chems, though when viewing items in e.g. the crafting interface you will still see the default chem duration.
  • Works well with the BioCommMesh mod for chest armor pieces. A single use of jet will last 30 seconds with rank 4 of Chemist, and for 45 seconds with rank 4 of Chemist and the BioCommMesh mod.
  • In the Survival mode, Chemist rank 1 is required to manufacture many items that previously required no rank in the skill, such as a stimpak.
  • When viewing the perk the "Potion Created" sound effect from Skyrim, another Bethesda RPG, can be heard.
  • In Survival mode, Chemist lengthens the heal over time of many different items, including RadAway, without modifying the healing per second.