Ordering Recommendation

Use to directly measure free estradiol. May be used to evaluate estradiol status for individuals with protein-binding abnormalities or individuals on hormonal contraception.

To compare this test to other estrogen tests, refer to the ARUP Estrogen Tests Comparison table.


Quantitative Equilibrium Dialysis/High Performance Liquid Chromatography-Tandem Mass Spectrometry




2-10 days

New York DOH Approval Status

This test is New York DOH approved.

Specimen Required

Patient Preparation

Serum separator tube or green (sodium or lithium heparin), Red Top, Plasma Separator Tube.

Specimen Preparation

Separate from cells ASAP or within 2 hours of collection. Transport 2 mL serum or plasma. (Min: 1.0 mL)

Storage/Transport Temperature


Unacceptable Conditions

After separation from cells: Ambient: unacceptable; Refrigerated: 1 week; Frozen: 6 months

Reference Interval

Test Number
Reference Interval
  Estradiol, Free by Dialysis
Male (pg/mL)
Female (pg/mL)
Children Not Applicable Not Applicable
Adult Not Applicable 19 years and older
Follicular Stage: Less than 2.4 pg/mL
Mid-Cycle: Less than 3.1 pg/mL
Luteal Stage: Less than 2.6 pg/mL
Postmenopausal Stage: Less than or eaual to 0.5 pg/mL

Interpretive Data

No reference intervals have been established for prepubertal females or for cisgender males. For a complete set of all established reference intervals, refer to ltd.aruplab.com/Tests/Pub/2006160.

This test was developed and its performance characteristics determined by ARUP Laboratories. It has not been cleared or approved by the US Food and Drug Administration. This test was performed in a CLIA certified laboratory and is intended for clinical purposes.

Compliance Category

Laboratory Developed Test (LDT)


Hotline History


CPT Codes



Component Test Code* Component Chart Name LOINC
2006161 Estradiol, Free by Dialysis 2240-0
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.


  • High-Sensitivity Free Estradiol
Estradiol, Free, by Dialysis and Mass Spectrometry