There are flush-free varities of Niacin available - both niacinamide & a couple of others... I was taking up to 3000mg of it daily for a month as a cholesterol-lowering experiment, along w/eating more oatmeal & Omega-3 fatty acids. It didn't have a huge noticeable effect, but once I switched back to using butter from margarine & cut down on my coffee consumption, my cholesterol & triglycerides did come down.

Now the challenge is raising my proportions of HDL to LDL.