Interesting niacin facts:

• In the body, tryptophan can be converted to niacin or serotonin. If niacin is short, it gets preferentially converted, and serotonin gets shorted. So those of us who need the niacin get better brain balance from it.
• Niacin is Master Detox. The occasional heart racing is the body doing so: that's the theory, anyway, but one again I have no explanation. I have been waking up at 2am with my heart beating a little fast, then it goes away and I go back to sleep. And the sleep I do get, is better.
• Niacin thins the blood through its anti-inflammatory qualities. But this doesn't explain the menstrual behavior. Detox shaking down stray estrogen?
• There's a lot of articles basically warning "Niacin will kill you." Though there isn't any recorded niacin deaths. And these same articles urge people to take statins instead. So I am not worried.

Also, a lot of the "niacin" articles actually turn out to be about prescription, slow-release, or other forms of niacin that try to avoid the flush; and so, they aren't niacin. I saw the same thing when I was researching progesterone; the scariest studies were done with the artificial Progestin; but you had to dig to find that out.

To me, it's just another form of "Eating Atkins will kill you!" And we all know how that one turned out.