I'm sure you realize, upon reflection, that this is forum hardly a "funnel for
Defy." In stating that it is you cast a shadow on the work that Nelson and his co-founders have done in creating this site, to say nothing of the efforts of all of us who turn to it regularly for discussion.
Defy and its medical staff play a large role here for one reason - they know what they are doing. I can assure you that, as a moderator, I would love to be able to refer men looking for quality health care to doctors near their home, and in some instances that's been possible. However, the lack of knowledge demonstrated by so many physicians time after time results in a preponderance of the referrals made here resulting in treatment by
Defy. I am not a patient, I don't live in the United States, so my opinion of
Defy is not colored by any personal interest.
As to the matter of your original post, the following are some relevant citations that support the thesis that estradiol is an important male hormone.
Asian Journal of Andrology, 2016, May-June,
The Role of Estradiol in Male Reproductive Function, Schulster, Bernie, et al
"Estradiol in men is essential for modulating libido, erectile function, and spermatogenesis... both estrogen and testosterone were required to increase libido, whereas neither hormone could achieve the effect alone suggesting that estrogen plays a necessary role in sexual desire in the setting of low testosterone."
New England Journal of Medicine, 2013, September 12,
Gonadal Steroids and Body Composition, Strength, and Sexual Function in Men, Finkelstein, Burnett-Bowie, et al
"As serum testosterone levels decline, there is a concomitant decline in serum estradiol levels. Nevertheless, the consequences of male hypogonadism are routinely attributed solely to androgen deficiency; the potential role of the concomitant decline in estrogens is typically ignored. It has become clear, however, that estrogen deficiency may be important in the pathogenesis of some consequences of male hypogonadism...decline in both (testosterone and estradiol) both contributed to the decline in sexual function."
American Society for Bone and Mineral Research, 2016 Annual Meeting, Claes Ohlsson, MD, The Institute of Medicine, University of Gothenburg, Gothenburg,15 Presentation September 10, 2016, "Low Oestradiol Increases Fracture Risk"
Journal of Clinical Endocrinology and Metabolism, 2016, August,
Testosterone Treatment and Sexual Function in Older Men With Low Testosterone Levels, Cunningham, Stephens-Shields, et al
"Increases in total and free T and estradiol levels were associated with improvements in sexual activity and desire, however no threshold upper limit was established."
Canadian Urological Association Journal, 2015, SeptemberFazio, Gilbert,
Are We Considering Low Estradiol's Presentation?"
"In the clinical situation, many men on TRT fear elevated estradiol, and doctors suppress e2 with anastrozole. Frequently such adjunctive therapy results in loss of libido, erectile dysfunction, fatigue, lethargy, and joint/muscle pain. Research has shown that it is possible to treat estradiol in to aggressive a fashion. Our own experience causes us now to hesitate prescribing an AI if other means and methods to manage e2 have not been considered."