Note: I am most genuinely weirded out that Death is on this list, but the final meaning of choosing it is actually not that dark at all, it'd simply be an exaggerated way to say one is very passive, more so than choosing Paralytic. So, that's how I would mean it. I just didn't want to omit such an important serum for the question about them.

I was a bit confused by this question, but if it’s what I thought it meant, I chose simulation serum as I feel that if I’m GP it wouldn’t affect much or at all.

True, it was tricky to put it in the one sentence for the title. I meant basically which serum's consequence is the least different from how you act anyways, for example, if I took Peace Serum, I wouldn't act much different than how I often do. So, I did assume the serums work on us when I asked, although you make a good point, and then the similarity of our personality to what the serum does could be a factor that decides how much it affects us, so your logic comes down to the same thing as I meant to ask. In any case, I'd guess you'd answer Simulation, from what I know about you.

These actually do kinda are based on faction somehow, like it would make sense when people choose peace serum that they would be amity.

I agree, Amity and Candor are the most obvious.

Dauntless is also connected to overcoming fears.

Abnegation- I suppose it can be related t forgetting oneself, and disapproving of curiosity.

I'd say Erudite is assigned because it was needed for the plot, but I can find some sort of logic in one of their jobs being medicine, so the serum can be used for the same purposes euthanasia is done irl; and there's also a metaphorical meaning of the faction's practicality, removing things that are no longer functional.