Figure 2.

Schematic example of the relationship between receptor occupancy and hormone concentration. In this theoretical example, at low concentrations, an increase in hormone concentration from 0 to 1× causes an increase in receptor occupancy of approximately 50% (from 0 to 50%; see yellow box). Yet the same increment in hormone concentration at higher doses (from 4× to 5×) causes an increase in receptor occupancy of only approximately 4% (from 78 to 82%; see red box). However, it is important to recognize that receptor occupancy is not linearly related to hormone effect, and low receptor occupancy (1 to 10%) can be associated with maximal effects. [Reprinted from L. N. Vandenberg et al: Hormones and endocrine-disrupting chemicals: low-dose effects and nonmonotonic dose responses. Endocr Rev. 2012;33:378–455 (133), with permission. © Endocrine Society.]