It is often used as a cholesterol lowering therapy.
I should point out that no matter what some people might hear or read about this on the net, Niacin in very large doses can have some not-so-good effects on your liver.
So DYODD, and if you are unsure, talk to your health professional.
I do have a liver function test every year as I continue to take Zetia but the recommended dosage of Niacin does the trick for me.