When measuring testosterone levels, it is critical to determine the levels of both free and total testosterone to understand the cause of any observed symptoms of deficiency (Khosla et al 2008).
Because of difficulties with equipment standardization and inter-laboratory variability, it is recommended that physicians consistently use the same local laboratories and gain familiarity with the accuracy, precision and definition of normal values for the assays offered in their communities (Morales et al 2010).
Hormone therapy plays a critical role in gender reassignment from male to female. A transsexual in the hormone therapy stage is in effect going through a second puberty, causing the body to change. For a man, the amount of estrogen during therapy is comparable to that of a woman during her menstrual cycle, while the amount of testosterone in the body is actually less than what is produced by a woman. The maximum amount of time hormone therapy lasts is approximately 4 to 5 years, but many transsexuals choose to have sexual reassignment surgery before this. Transsexuals who choose to remain non-operative must choose other options in order to continue their hormone therapy after this time period.
There is considerable controversy over the earliest age at which it is clinically, morally, and legally safe to use GnRH analogues, and for how long. The sixth edition of the World Professional Association for Transgender Health 's Standards of Care permit it from Tanner stage 2 but do not allow the addition of hormones until age 16, which could be five or more years later. Sex steroids have important functions in addition to their role in puberty, and some skeletal changes (such as increased height) that may be considered masculine are not hindered by GnRH analogues.