Quote:
|
Originally Posted by Andromeda Since 11 Sept 2006 Ive been taking 10mg of Tamoxifen (Nolvadex) daily to get rid of my gynecomastia. It has progressed, albeit slowly, and just today I had my followup Dr visit to review my ongoing treatment.
At this visit we reviewed my latest blood tests to monitor hormonal changes since starting the treatment. Now these results were stunning. My estrogen levels were actually higher than before starting the Nolvadex
At the same time testosterone was slightly higher , with bound testosterone showing itself to be even higher relative.
For those who want to see/compare raw figures I have the following.
Pre Nolva: 3 weeks Post Nolva:
Testosterone - 35
Free T: 68 69
P4: 200 300
E2: 198 300
I have recently had an ultrasound of both my testicles and chest. So far the testicles are fine, and I assume the Endo would have called if the chest results (not held at the time) came back unusual... so it seems to rule out the possiblity of an E2 secreting tumour.
Please come forward with your suggestions on how this has come about as my Dr has no idea till we see the next set of tests. I'm now taking double the amount of Nolvadex (20 mg now) with followup tests to be done again in about 3 weeks.
Any advise on this mystery would be appreciated...
Cheers in advance, |
Measuring Estradiol alone is going to be thrown off when taking
Tamoxifen (name brand: Nolvadex).
Tamoxifen acts essentially as a mild estrogen. It blocks estrogen receptors in some tissues (particularly breast) so that the stronger breast-tissue growing estrogen (estradiol) cannot act on the tissue. Tamoxifen acts like an estrogen in other areas of the body (which is why it may cause blood clots and in some cases, cancer).
Measuring estradiol alone is actually a measure of all the estrogen activity, heavily weighted for estradiol - the most potent estrogen. Since
Tamoxifen acts as an estrogen, it raises the measurement for estradiol.
Measuring estradiol alone when taking Tamoxifen is thus not accurate.
To measure estrogens when taking Tamoxifen, it is better to obtain Fractionated Serum Estrogens - where the estrogens are separated into the different estrogens then each is separately indentified. This will reduce the influence of Tamoxifen.
Estrogens raise SHBG. I would not be surprised that SHBG is raised by Tamoxifen, since Tamoxifen acts like an estrogen.
The brain measures the level of estrogen and
testosterone to determine how much Luteinizing Hormone (LH) to produce. LH production leads to an increase in testosterone production. Estrogens are then produced from testosterone via the aromatase enzyme.
Tamoxifen - by blocking stronger estrogens in the brain - gives the brain the false impression that there is less estrogen available. The brain then raises LH production, which then raises testosterone production.
As a side note, when progesterone is available, the brain more easily senses testosterone levels.