Laboratory Tests Required Before Starting Testosterone Therapy

Core Laboratory Tests

The American Urological Association recommends measuring serum luteinizing hormone (LH) levels to determine if hypogonadism is primary (testicular) or secondary (hypothalamic-pituitary) in origin, which helps establish the etiology and guides treatment approach in a 38-year-old male with hypogonadism 2, 4
The Endocrine Society suggests measuring serum prolactin levels, especially in patients with low testosterone combined with low or low/normal LH levels to screen for hyperprolactinemia, which could indicate pituitary tumors 2, 3
Baseline hemoglobin/hematocrit measurement is mandatory before starting therapy, and if hematocrit exceeds 50%, consideration should be given to withholding testosterone therapy until the cause is investigated in a 38-year-old male with hypogonadism 1, 3
The American Heart Association recommends evaluating for atherosclerotic cardiovascular disease (ASCVD) risk factors, including both fixed (age, male gender) and modifiable factors (dyslipidemia, hypertension, diabetes, smoking) in a 38-year-old male with hypogonadism 1, 3

For men over 40 years of age, the American Urological Association recommends measuring PSA to exclude prostate cancer, and although the patient is 38, this may not be immediately required but should be considered if there are any prostate-related concerns 1, 3
The Endocrine Society suggests measuring estradiol if the patient presents with breast symptoms or gynecomastia prior to starting testosterone therapy 2, 3

If the patient is interested in preserving fertility, the American Society for Reproductive Medicine recommends measuring follicle-stimulating hormone (FSH) to assess reproductive health status in a 38-year-old male with hypogonadism 1, 2, 3
The American Society for Reproductive Medicine suggests considering semen analysis if the patient has fertility concerns, especially with elevated FSH levels which may indicate impaired spermatogenesis 1, 3
The American Society for Reproductive Medicine recommends offering karyotype testing and Y-chromosome analysis for microdeletions if severe oligospermia or non-obstructive azoospermia is detected in a 38-year-old male with hypogonadism 1, 3

The Endocrine Society recommends considering pituitary MRI if total testosterone is low with low or low/normal LH levels, regardless of prolactin levels, to rule out non-secreting adenomas in a 38-year-old male with hypogonadism 2, 3

The American Urological Association recommends re-evaluating hemoglobin/hematocrit 3-6 months after starting treatment, then annually, and if hematocrit exceeds 54% during treatment, intervention is required (dose reduction or temporary discontinuation) in a 38-year-old male with hypogonadism 3

The American Heart Association notes that injectable testosterone is associated with the greatest treatment-induced increases in hemoglobin/hematocrit, which may increase the risk of polycythemia in a 38-year-old male with hypogonadism 3
The American Society for Reproductive Medicine warns that testosterone therapy can suppress spermatogenesis through feedback inhibition of pituitary FSH, and patients interested in future fertility should be counseled about this risk 1
The American Urological Association recommends considering baseline PSA as part of comprehensive evaluation, although it is not required for men under 40 without risk factors 3