Hi, from my litany of problems with VENLAFAXINE = aka EFFEXOR in USA, your " jet lag", is attributable to EFFEXOR withdrawal. I am experiencing your problems (& alot more). I spent 2 years titrating off (from only 75mg !) getting down to taking beads out of a 37.5 slow rel capsule & diluting them! I kid you not. Luckily, you were on it only a very short time, so I guess your issues will be short lived. The longer you are on it, the longer these symptoms take to cease . AND, as you observe, they go away , and come back ! Severe problems are seemingly all down to genetics. Some people have no issues at all. I have read the drug gets absorbed into your body fats / cells. Thus causing "withdrawal issues" as your body tries to rid itself. Hope this helps .