There are many things in olive leaf extract that could be possibly causing my relief. Oleuropein, oleocanthal, polyphenols... I just am not sure. But B Jim before you give up make sure you try the real thing (olive leaf extract). I have no idea what else could be different about this as compared to olives. Something tells me the OLE is a lot more concentrated in a certain ingredient which helps. All you have to do is buy it at wal-mart and it is not that expensive but it is worth a try from my perspective.
Again, I am one of those people who found some sort of a relief from antihistamines if taken 30 minutes BEFORE orgasm, make sure you feel it in you, I weigh 150 lbs and 900 mg is needed. Also my reaction is 100% cognitive other than slight skin redness/swetting indicating an allergic reaction. OLE has helped me the most and I can avoid the tortuous reaction after "O" if taken 30 minutes BEFORE orgasm. I believe it is best to take this say "once a week" and not everyday since your body may build up some immunity against it and hence you will feel the POIS reaction, but for this I am not sure. I know Matsoda had success drinking OLE in a water bottle every day.
Currently I have about 3 "O's" on the weekend in one session and can avoid the worst of POIS. Sometimes the brain fog comes a few days after, but it is very slight and usually occurs if I mess up by "O'ing" more or by drinking beer or food that causes bad reactions. This reaction is a lot better than the traditional POIS route.