If you started taking faverin , when can side effects appear ? the first week or from the 3rd week ?

Side effects: Side effects can happen from when you first start taking a medication. Since faverin requires several weeks' consistent dosing for therapeutic effectiveness, you may be exposed to side effects before therapeutic effects occur.

Faverin = Luvox (fluvoxamine) : I think you mean beneficial effects instead of side affects. Beneficial effects can begin as early as the first week and are usually apparent by the third week. However, in obsessive compulsive disorder it is not at all unusual for the maximum benefit to not be seen until at least 12 weeks out. Best wishes.