It is difficult to review this medication, because technically it has worked wonders for me, yet miss a dose, and it is absolutely debilitating. I suffered from panic attacks for years and tried a variety of anti-depressants to treat them. Most worked marginally well, and usually came with some unwanted side effects, particularly weight gain. On Effexor, though, I feel like I've had my life returned to me, and there are practically zero side effects, provided you take it every day. I am able to function so much better on a daily basis, and have been living a fuller life since starting this medication. Now for the downside. I once missed a single dose because my pharmacy ran out, and within 6 hours of my normal dose time, I started feeling the effects. Within 12 hours, I was sweating, nauseated, jittery, confused, etc. I could barely sleep that night, and when I did, I had horrible nightmares. The next day, I awoke feeling nothing like myself. Literally, I felt like a different person was in my body. I was incredibly irritable and had the worst vertigo I've ever experienced. It was all I could do to get to the pharmacy once they had more, and within a couple hours of taking my dose, I was nearly back to normal. After that incident, I did a great deal of research on this drug, and found that my experience was not uncommon at all, yet neither doctors, nor the warnings on the medication, nor the advice on site like this list any of these problems as a possibility. I think a lot more people would be very hesitant to start this medication knowing how crippling it would be to try and get off it. As some other reviewers have said, if there is any other option available to you, even if it doesn't work perfectly, I would strongly advise using that instead of starting an Effexor regiment. God willing, I will never miss a dose again, and God help me if I ever need to stop. :(Read More Read Less