I tried Niacin 1500 MG throughout the day. I could not take 500mg at a time more than twice a day because my body would turn so red like a sunburn and get itchy. Lasted for up to 90 minutes. It DOES increase circulation, I could feel it throbbing through to my lips. I continued for I think 3 weeks with no results. Stopped muscle pains Id been having during the flushing.
It was because people looking at me weird when I was red is why I stopped. If you can tolerate it, good luck to you.