I was on a regular effexor for about 4 weeks and felt amazing, had energy, felt happy, and could actually focus/concentrate. Was switched to greenstone venflaxine er and i feel blah, lack of energy, and i have no motivstion to do anything what so ever. It also barley works for my depression it just makes me feel nothing.. My pharmacist says it comes from the same plant and is mad of the same product as brand name effexor, im starting to get frustrated with him not believing me while my doctor is. Any comments would be appreciated!