Hormone Levels while on Tamoxifen

From my understanding, Tamoxifen does not stop your body from producing estrogen.  It "tricks" any cells that use estrogen to grow by attaching itself to them rather than the estrogen.  Basically starves them to death.

Here's what they have to say about it on "Livestrong"
Tamoxifen is a member of the selective estrogen receptor modulator (SERM) class of drugs. Tamoxifen binds to tissues that use estrogen. This binding blocks the action of estrogen in the breast but mimics the action of estrogen in the bones and uterus. Tamoxifen is used to treat estrogen positive breast cancer in men and women and to prevent breast cancer in women at high risk.
Estrogen-positive cancers require estrogen to grow. Tamoxifen binds to the cancer cells in these tumors but does not stimulate them. This prevents estrogen from binding to the cancer cells. Tamoxifen does not kill cancer cells, but it keeps them from reproducing.
In the STAR study, tamoxifen reduced the risk of both invasive and noninvasive breast cancers. Noninvasive (also known as "in-situ") breast cancers are those that are confined to a breast lobule or duct. Invasive cancers are those that have started to spread to surrounding breast tissue.

Read more: http://www.livestrong.com/article/27290-tamoxifen-work/#ixzz2ZQHzU6Jt

When I first starting taking tamox in 2006, I was 50 and just on the cusp of menopause.  After a few months, my estradiol numbers went through the roof.  At one point, they were 100x normal.  I took a break from the tamox - I think 2 months - and the numbers came down.  I continued on the drug and my numbers came back into the "on the cusp" range.  I'm sorry I can't remember the exact numbers.  By the time I was finished with tamox and AIs, I was absolutely and completely in menopause.

The docs never explained the high estradiol.  They seemed puzzled.  I had a couple of intravaginal ultrasounds and my ovaries were enormous but they went down to nothing after taking the break.  The last time I had an ultrasound (2 years ago), they couldn't find my ovaries!  That's okay.  Better to be non existent than huge!