When I first dropped it, Everything went haywire, I was getting erections every time I saw a covergirl commercial.
But it slowly leveled out, to the point where I'm not sure If it's the same as it was before propecia, but pretty damn close. Certainly better then it was while on propecia.
All in all about a month.
Important to note I took finasteride for 11 months, so you should have no problems since you only took it for 3.