Niacin, my personnal 1st trial :
I have eaten little glucide (bread,Nutella) took Niacin 500 mg in a half full stomach and got an intense flush after 20 minutes (tingling inside the brain and red upper part) . I started to get aroused when I felt this flush and then decided to get an O about 1 hour later and I still got a part of the flush after the O. I am feeling in POIS right now
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I hope it was just a wrong way to use it... do you have some advice? thank you 
I agree with Daveman when he says that you should try lower doses. I only needed 100 mg Niacine after a light breakfast(fruits, compotes) to have a very intense flush. For what i´ve read it seems that you have to wait until the flush pass away. My flush lasted near 10 minutes, and then i decided to wait another 30 min to have the orgasm.
And i just have had some thoughts to share;
I would want to ask if someone has taken niacin of rapid release, didn´t get the flush due to lower dose or full stomach and then had the Orgasm without POIS symptoms, or at least with lowered POIS symptoms. It seems that the flush with the XN is not as intense as the niacin and it works better?.
It is paradoxical, but the people avoid this kind Niacin due to this flush effect. But if we really need the flush, it would be interesting to find things that will assure this flush every time you take a dose of niacin without increasing it during the days. Powdered niacin as some have pointed out, it´s a solution, like drinking hot beverages as tea, coffee or chocolate. For my case, it´s clear that i don´t want to use the niacin every day, cause i don´t want to build-up any tolerance to it and not cause the flush... If this flush is really neccesary for breaking the POIS cycle(maybe this release of histamines blocks the POIS own "bad release?... It´s very significative that you have to wait until the flush pass away, don´t you think?...).