That flush is the creepiest thing I have ever felt but it doesn’t seem to hurt anything. It’s just creepy.
It gets easier. It’s never again like the first time where you freak out a little. Pro tip: get bulk niacin or open your capsule and mix with water. The flush is almost immediate and does not last as long as from a pill (or surprise you). I throw back 1g every morning and still have a little flush.