After the 1 st intramuscular injection of 1000 mg testosterone undecanoate to hypogonadal men, mean Cmax values of 38 nmol/L (11 ng/mL) were obtained after 7 days. The second dose was administered 6 weeks after the 1 st injection and maximum testosterone concentrations of about 50 nmol/L (15 ng/mL) were reached. A constant dosing interval of 10 weeks was maintained during the following 3 administrations and steady-state conditions were achieved between the 3 rd and the 5 th administration. Mean Cmax and Cmin values of testosterone at steady-state were about 37 (11 ng/mL) and 16 nmol/L (5 ng/mL), respectively. The median intra- and inter-individual variability (coefficient of variation, %) of Cmin values was 22 % (range: 9-28%) and 34% (range: 25-48%), respectively.
d) HRT Failure . The above study did not really address the issue that sometimes a man waits and waits for HRT to fix his issues and it simply never happens. This is not necessarily a disaster, because it often a) means that one has other more critical underlying issues such as hypothyroidism, or b) that the protocol needs tuning. In the case of the latter, high estradiol is a common culprit, since it essentially negates the beneifts of the increased testosterone levels. In both of these cases, it pays to have a knowledgeable and experienced physician overseeing your therapy.