Hi PG,
I am not using niacin, and I do not date neither, so cannot share my personal experience about this.
However, another member using my pre-pack ( that has no niacin ), told me in PM that he carries it in his pocket when dating. When he sees he will need to take it, he does so while going to the toilet. My pre-pack method is very effective for him, and his POIS goes unnoticed.