It is a strange organic concoction that could possibly reverse the Mutation Factor in humans.

The mutagenic serum is a quest item in Fallout 2.


The mutagenic serum does not work as intended; it will kill any mutant to whom it is injected, with the exception of Frank Horrigan.


Developed by Dr. Henry, it can be given to the Chosen One having a Science skill of 80% or more.

Related quests


  • It must be noted that using the serum in a duel with Lenny is buggy; it appears that once combat damage is done to Lenny, the serum will work and the fight will end, but if used at the beginning of battle, the game gets frozen permanently in combat mode.
  • If the serum is used on a super mutant in combat mode, it gives the 1000 XP and completes the quest but the mutant will take one or a few turns before dying. If the mutant is killed before the serum takes effect and the corpse is looted, the mutagenic serum may still be there.
  • The serum does not work on Frank Horrigan because he is not a regular super mutant.