Effexor XR is available in capsule form, with dosages of 37.5mg, 75mg, and 150mg. Its active ingredient is venlafaxine. It is predominantly prescribed for the treatment of depression, anxiety disorders, panic attacks, and social anxiety disorder (social phobia). Effexor XR belongs to a class of medications known as serotonin-norepinephrine reuptake inhibitors (SNRIs). These medications function by helping to restore the balance of specific natural chemicals, serotonin and norepinephrine, in the brain. Effexor XR is also available under alternative brand names such as Venlift, Veniz XR, Venla-XR, and Venlor XR.