Men commonly ask the following questions when they inquire about testosterone therapy:
1) What should my testosterone level be for my age?
2) Is my testosterone level too low for my age?
3) How high should we aim to get my serum testosterone level on testosterone therapy?
There is no defined level of serum testosterone for a man by age. Rather, we utilize a reference range of testosterone levels from 250-950ng/dL as being within normal. There are many variables that can account for a man’s serum testosterone level that include age, genetics, muscle mass, fat mass, diet, exercise routine and co morbidities. Therefore, when a man asks “what is a normal testosterone level” the answer is between 250-950ng/dL.
When measuring your serum testosterone, a testosterone level measured in man to be below 150ng/dL should have an addition workup. A testosterone level below 150mg/dL needs be investigated to rule out other pathologies emanating from the pituitary gland. A level less than 150ng/dL is considered to be too low for a man.
Some men, may experience symptoms of Low-T that include lack of energy, decreased muscle mass, loss of sex drive, erectile dysfunction, decreased stamina, weight gain, impaired concentration and fatigue even when their testosterone level may fall within the normal reference range. Is it ok to treat a man with testosterone therapy even if their serum testosterone is within the normal reference range? The answer is yes, provided that no other factors are responsible or contributing to the patient’s symptoms. There exists genetic variability in the androgen receptor and its effect on the human body that varies between men. Some men may have no symptoms of Low-T while other men do not, even when their serum testosterone levels are the same. This can be accounted for by genetic component of the androgen receptor and how men respond to Low T thearpy.
We aim to keep a patients serum testosterone level in the high normal or supra-physiological range while monitoring labs every 3-6 months. Factors that can limit a men’s testosterone from being in the high supra-physiological range include medication side effects on the body, elevation in hemoglobin and hematocrit, rise in prostate specific antigen among other laboratory values.