For those watching at home, the first flush is bad and scary. I’m not gonna lie.
A practial joking friend of mine dosed me and another guy with several pills and it was interesting, I started taking it for a while and kinda enjoy the flush.
Not knowing its harmless was uncomfortable part in his little joke.
My mother thought I was trying to kill her. If you are seriously deficient in niacin, the flush can indeed be scary.