I’m ok with niacin ATB, yes I get the flush but after a few days it stops.
If you increase the dose it starts again for a few days and so on.
There’s a long thread on Every Woman over 29, regarding B6 causing irritability in some, but nobody seems to know why!
It’s very uncomfortable, not take a pain killer level of pain. Bizarrely if I wake up in night and pain comes after about an hour I always manage to go back to sleep afterwards, if the pain doesn’t come I can’t. So it has its uses!