Free estradiol and sex hormone-binding globulin

SHBG is a plasma protein that participates in the regulation of free estradiol and free testosterone in plasma. We discuss the concept of the nature of a free estradiol and how best to ascertain its value. It can be measured or calculated; the ways in which this can be done are explored along with the advantages and disadvantages of each. (C) 2014 Elsevier Inc. All rights reserved.