@rsc
I'm not coming up with anything either, except anecdotal information from various comment groups. I did read that letrozole's half-life is two days, and that it should be out of your system in 4 days. However, that says nothing about how long it will take a body to adjust to its (or any AI's) absence, especially after 5-10 years. My guess is that no one has studied the subject... regrettably.