Letrozole kills libido, try Arimidex or Aromasin instead, and use DHEA 50mg and Tribulus with it. There are no PFS “crashes,” associated with AI use, what is occurring is an E2 crash, this is not a PFS problem. If you are going to use an AI, use a test booster along with it to keep your test and estrogen boosted, so that way you can realize the effects. If you aren’t going to use testosterone, that is the best way to do it, DHEA will give a lot of benefits as well.
Letrozole has worked for some guys, but it is a poor choice, simply due to being notorious for killing libido. You may want to try Torem instead, it is the most effective endogenous testosterone booster Serm, and it is also an estrogen blocker. Torem is the most effective Serm at restoring the HPTA. With PFS, not only does your testosterone crash, but your cortisol does as well, you may very well recover from the 5AR aspect and never know it is your testosterone is wrecked, or your cortisol is wrecked.
Dr Jacobs will tell you that Total Testosterone does not mean much, it is the bio available test that does, and the point is that bio available test is always low in guys with PFS.
I thought I would stop in and post this, please come and join us at solvepfs.com, we welcome these kinds of discussions there. The more united this community is, the better off we all are, hope to see you guys there.