If we are talking about the nora traits, which are traits needed to research just to unlock the next tier, you are supposed to just deal with the side effects. You just need to raise it to mastery level 2, IRRC you start from 1 so you just have to make a serum with that trait and watch people drink it like 5 times (it's +0.2 mastery each observation). Turn in research after that and you are done. Also testing the serum with your head researcher after it's research can reduce the side effects as well.
If you just want to remove all side effects from all traits, raise the mastery with console command so that the side effect chance divided by the mastery level is less than 1. You can use console command to find the specific serum and set mastery to a ridiculously high value. I wrote a script a while ago that adds functions that you can call in the command console to set mastery levels of all researched traits to 1000, so every non-Nora trait produces no side effects.
Type "master_traits()" in the console command and it's set.
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