The single most important aspect of a successful TRT protocol is the doctor-patient relationship. If your doctor is not current with all the aspects of androgen replacement, and that includes monitoring estradiol via the appropriate assay, you will be fighting an uphill battle. Just as importantly, if your doctor fails to understand that you are a partner in this process, with a right to inquire and suggest in regard to your course of treatment, you are not well served. If, like me, you are fortunate to find excellent local care - great. Sadly, that doesn't happen as often as it should. That is why Defy is popular.