I don't have the facts to quote, but i've *lived* thru a valium w/d and it is no exageration to say that the BAD w/d's lasted almost exactly 13 days. I had been taking between 20-40mg per day, worked up to there over many years, and then I slowly and sucessfully tapered down to 5mg per day, taken at bedtime. I stayed at that level for a couple weeks and then thought it would be well enough to quit, as I was out anyway and didn't have the $ for a US OP nor the time for an IOP. It was AWFUL AWFUL AWFUL. It started off slowly enough, but like chinese water torture, it got more and more annoying and the different symptoms kept increasing as the days passed, with it reaching a peak at about day 6 or 7 and it took a full 2 weeks before it went away. And away, it went. It was so strange, but on that 13th night of no meds I finally fell into a deep, deep sleep (a first, at that point!) and woke up completely covered in sweat. But I felt better! I was suddenly hungry and I felt alive for the first time in a while. From that moment on, things started improving pretty quickly and by about day 20 I was about ready to try to face reality again.

Anyway, I have seen benzo half-life charts that cover the spectrum so I wouldn't bank too much on their accuracy. I think it has at least as much to do with individual body chemistry as it does the elimination rates of the metabolites.

L - below is an elimination chart for diazepam that I found on the Roche site