I've been on Effexor 150mg for a couple years. If I forget to take it, I get brain zaps. I have been on a diet plan to speed up my metabolism this week, and been getting brain zaps the past few days. The only thing I can put it down to is that my metabolism is speeding up and changing the way I metabolise the drug. I usually take it at night, and am getting the brain zaps in the afternoon. Perhaps I should change the time of day I take it now? Can anyone advise on this?