Effexor weight gain, when using the drug is possible. However, weight loss is the more probably side effect. In truth, adding a few extra pounds may be the least of your problem. A more dangerous side effect is the increased tendency to have suicidal thoughts and then act upon those ideas, even though it is meant to combat depression. In fact, this consequence alone seems like a good reason to take another drug. Nevertheless, if you want off the medication, you need to consult your doctor and do it with his/her supervision. You may also experience bleeding problems, irregular heartbeat, and more. So, carefully consider the potential risks, as well of the benefits, before starting to take the drug.