What are some of the side effects when you try to wean off of Effexor?

At this point I feel anger towards these drug companies and the courts that won't allow them to be held accountable. Twenty-five years ago I was put on Effexor when it was new just for chronic fatigue. I had young children and probably needed a vacation. Since then I tried to get off the drug but the withdrawal was terrifying. That was the only reason I stayed on for so long. Finally at 62 I stopped, but had to be put on Lexapro and for a short time Xanax. After two years on Lexapro I weaned off that (because it made me fall asleep constantly), without the help of Xanax... no doctor would give it to me because I was extended traveling. Now all hell broke lose. My heart developed a severe arrhythmia, high blood pressure and flu type illness. Then my immune system was so weak I got Valley Fever in my lung, which most people recover but I need medication. I also had brain zaps and vertigo for several months but the other symptoms are so bad now I haven't noticed those at this point. For sure these poisons have shortened my life. They lie about the dangers. Stay away from antidepressants!! The cortisol is raging through me even after four months, the anxiety is horrendous.

Hi, joanrol!
Anxiety, crying spells, depression, "brain zaps", headache, insomnia, nausea/vomiting are the most common and depend on many factors. The length of time, the dosage, and your individual metabolism. It can be tough for some people and may take weeks, even months.
Other people can discontinue the medication without many or all of the symptoms.
I took venlafaxine (Effexor) for over 7 years at 225mg/day and tapered off over 2 weeks with only a mild headache in the beginning couple of days.
Be patient because it can take 4-8 weeks for the drug to reach therapeutic levels and even 75mg is only the initial recommended dosage. You'll probably be feeling better very quickly now.