Niacin can do nothing to your hair but help its growth. Check this out:
http://www.holisticonline.com/Remedi...-nutrition.htm
"Hair loss occurs when the diet is inadequate in the B vitamins - especially B6, biotin, inositol and folic acid; and the minerals magnesium, sulfur and zinc. The B vitamins, especially B5 (pantothenic acid and
B3 (niacin), are especially important for hair growth."
Personally,
i noticed some decrease in the sense of "well-being" from time to time since i started it(and i am just on 500mg ED), although i am not sure if it is the reason, so beware of that. I am quite interested if anybody else has experienced that at any dose of this stuff.