Effexor XR is a timed-release medication used to treat depression. However, it is not without adverse side effects. The medication can actually increase suicidal thoughts in users. Thus, it seems to defeat the original intent of the dose, because patients have been known to act on these thoughts. In addition, the medication, coupled with treatment for migraines can create a condition called serotonin syndrome. If that is not enough, Effexor XR can cause an irregular heartbeat, seizures, weight loss, and bleeding problems, in addition to the typical side effects listed on the press release given out by the pharmacy. If you are suffering from adverse side effects from using Effexor XR, you need to see a doctor.