The PTH test is used to help identify hyperparathyroidism, to find the cause of abnormal calcium levels, or to check the status of chronic kidney disease. PTH controls calcium and phosphorus levels in the blood.

Insulin-like Growth Factor 1, also known as IGF-1, is used as a biomarker for blood levels of human growth hormone. It is a hormone produced by the liver and other tissues which affects growth-promoting activities and glucose metabolism. The blood level of IGF-1 appears to fluctuate over 24 hours and is found to be related to growth hormone secretion.

The adrenal gland produces a hormone known as dehydroepiandrosterone (DHEA). It is also made in the brain. DHEA leads to the production of androgens and estrogens (male and female sex hormones). DHEA levels in the body begin to decrease after age 30. Lower DHEA levels are found in people with hormonal disorders, HIV/AIDS, Alzheimer's disease, heart disease, depression, diabetes, inflammation, immune disorders, and osteoporosis. Corticosteroids, birth control taken by mouth, and agents that treat psychiatric disorders may reduce DHEA levels.

Cortisol (hydrocortisone) is the most prominent glucocorticosteroid, and it is essential for the maintenance of several body functions. The most important physiological effects of cortisol are that it raises blood sugar levels (enhances gluconeogenesis, or breaks down glucose) and lowers inflammation and the immune system.

This test measures the amount of dihydrotestosterone (DHT) in the blood.  Low DHT has been associated with low libido and high DHT has been linked to acne, hair loss and benign prostatic inflammation in a minority of men.

Pregnenolone is known as the mother hormone. All other steroids including testosterone and estrogen are derived from this important hormone. For this reason, optimal blood levels of pregnenolone are critical for a healthy hormone balance.  This test uses liquid chromatography/mass spectrometry, the most accurate assay for hormones.

A single fasting growth hormone (GH) level is of limited value. The secretion of GH is episodic and pulsatile. GH has a half-life of 20 to 25 minutes. Testing for growth hormone deficiency or excess is best done as part of a dynamic test involving specific stimuli (see the online Endocrine Appendices: Growth Hormone Stimulation and Growth Hormone Suppression). Insulin-like growth factor-1 can also be useful in assessing growth hormone status.

This test is not the sensitive estradiol test but the regular one. It is not recommended for men (it is adequate for pre-menapausal women).  The results from this test are usually available 2 business days faster than the sensitive estradiol test.

 Progesterone is a female hormone important for the regulation of ovulation and menstruation. It is also present in men in smaller concentrations. Progesterone is a steroid hormone that plays numerous roles within the human body. It is crucial to the production of sex hormones and corticosteroids, as well as playing a role as a neuro-steroid (brain function). 

This ultrasensitive estradiol test is recommended for men. The commonly used estradiol test may overestimate estradiol in men. That test uses immunoassay technology that cannot differentiate C-Reactive Protein (involved in inflammation) from estradiol, so it reads the combination of the two as estradiol. This ultrasensitive estradiol test is based on liquid chromatography/mass spectrometry (LC/MS), an assay technology that does not have that limitation. 

Important note:  The blood sample is sent out to Quest Diagnostics Nichols Institute San Juan Capistrano, Caifornia.  Overnight delivery and testing is performed on Sunday and Friday.  Reports are available within 5-7 business days from the time the specimen is collected.

 A prolactin blood test is used by doctors to evaluate sexual dysfunction or very low testosterone blood levels of unknown causes in both men and women.