It seems to depend on the person, some people quit without feeling anything (or claim to). I don't take very much (9g a day max) and don't take it regularly, so I've avoided becoming too dependent I think, but if I take it a few days in a row and stop, i feel a little rougher than usual for about a day or two. Sometimes it feels like I have a cold coming on the day after, and I get more tired than usual for one or two days. If I stop at night, I can feel it the next day by the afternoon, so that's about the window of time you are at.