FSH and LH are produced by the pituitary gland to control the production of sex hormones including testosterone and estrogen, and sperm and egg cells. They are both important in diagnosing primary or secondary hypogonadism, infertility, or potential pituitary adenomas.

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.

SHBG (sex hormone binding globulin) binds to testosterone and estradiol. High SHBG may decrease free testosterone and free estradiol.

The thyroid stimulating hormone (TSH) is produced and secreted by the pituitary gland and stimulates the thyroid to produce T3 and T4. When TSH is elevated, low thyroid function may be indicated. If TSH is low it is indicative of high thyroid function. A study found that TSH was suppressed in all subjects after food, so fasting may be suggested although it is not reqired by Quest. Free T4 and Free T4 values did not change significantly after eating.

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.

This test measures levels of drenocorticotropic hormone (ACTH), which is also called adrenocorticotropin and corticotropin, a hormone made in the anterior pituitary gland that tells the adrenal glands to release cortisol, DHEA, and aldosterone. The ACTH plasma test quantifies the blood's level of ACTH. A patient's blood is drawn for the test and then sent to a lab for examination. The test findings enable the diagnosis of ailments such as Addison's disease, Cushing's syndrome, and adrenal tumors

This Testosterone Panel Includes 5 Tests:

• Testosterone, Total, LC/MS (most accurate testosterone test for men with high testosterone and women, no upper or lower limit)
• Testosterone, Free. Free testosterone is best calculated based on the LC/MS-derived total testosterone and equilibrium dialysis-derived percent free levels. 
• Testosterone, Bioavailable. Bioavailable testosterone is calculated based on the LC/MS/MS-derived total testosterone,  free testosterone levels, albumin and SHBG.
• Sex Hormone Binding Globulin (SHBG)
• Albumin

Note: Despite SHBG not being listed on the lab requisition form under "Testosterone, Free, Bioavailable, and Total, Males (Adult)," rest assured the results include this critical component, as it's necessary for calculating bioavailable testosterone.

This panel includes comprehensive testing of the thyroid stimulating hormone (TSH) in addition to free thyroxine (T4) and free triiodothyronine (T3).