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.

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.