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.
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).