Im a newbie here, but have posted in substance absuse forum. Anyway, my doc put me on effexor 37.5 mg once a day. it says that it takes four to six weeks to take effect.....can it happen sooner??

Considering this is my 7th day of going thru opiate wd's I feel wonderful loopy, like when i stand up or something. Anyway dont mean to babble but if anyone has any experience with this med, please post. Thanks so much in advance
Kooer