Chemist

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

Effects
This perk doubles the active time for chems.

List of items
The following items will work with this perk.

Fallout 4
In addition to the Chemist perk affecting the duration of chems, ranks in Chemist are needed to unlock some recipes at the Chemistry Bench usable in settlements.

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