Niacin supplements produce a temporary flushing effect that is
supposed to pump more oxygen into the inner ear due to vasodilation.
Take niacin on an empty stomach for best results. From The Tinnitus FAQ (T-FAQ)
When I am having a bad bout with Tinnitus the flushing effect of Niacin helps me (Niacinamide wont do it and imo is not effective as Niacin). I take just enough Niacin to get a good flushing effect and it helps to relieve it.