Dear friend. I have been off Effexor completely for about 6 months. I’ve had continual times of weakness and fatigue. Mine in part is due to recovering from a quadruple bypass surgery in late April of 22. Then it was in late May I found out my right lung was not working due to a phrenic nerve that was somehow damaged and caused my right lung to be paralyzed. I recently had a bad cold, and my breathing was really terrible. I was short of breath, and my oxygen level was very low, which has actually caused me to seek out professional advice from a thoracic surgeon at the Cleveland clinic since I’m an Ohio native. I really can’t quantify and say for sure how much of my fatigue and weakness has been caused by lack of oxygen, and how much has been caused from long-term side effects from the Effexor, although I believe most of my weakness and problems that I’ve had other than the shortness of breath are being caused by the side effects from being off of Effexor. I am supposed to call Cleveland Clinic tomorrow, Tuesday, February 20 and hopefully I’ll be getting an appointment there for an evaluation of my lung situation. In the meantime, you keep looking up and try to stay positive, try to be a faith filled person, because with God all things are possible.!!!