Enarei

Total Estradiol

Estradiol, also known as "serum estradiol" and "total estradiol", "17beta-estradiol", "oestradiol", and "E2", is a blood test that measures the amount of estradiol in the blood. It is used for dosing many of the medications used by transgender people.

In those who take feminizing hormone therapy, both high and low estradiol levels may cause long-term health problems. In the case of low estradiol, examples are menopausal symptoms and loss of bone density, while excessively high estradiol levels can significantly increase the risk of blood clots (Wiepjes, den Heijer, & T'Sjoen, 2019; Aly, 2020).

Expected values

Target values may differ between different countries, transgender health guidelines, and timings- and formulations of testosterone. The widely used Endocrine Society guidelines recommend that in transfeminine people, estradiol should be maintained around 100 - 200 pg/mL (367 - 734 pmol/L) (Hembree at al., 2017).

This is roughly in line with cisgender women, whose median estradiol levels across the menstrual cycle are approximately 100 pg/mL (Abott, 2009; graph).

Other information

This blood test is often confused with "free estradiol": a different blood test that is rarely used in transgender healthcare.

See also

References

  • Abbott Laboratories. (2009). Estradiol. Architect System. Abbott Park, Illinois/Wiesbaden, Germany: Abbott Laboratories. [PDF]
  • Aly. (2020). Estrogens and Their Influences on Coagulation and Risk of Blood Clots. Transfeminine Science. [URL]
  • Hembree, W. C., Cohen-Kettenis, P. T., Gooren, L., Hannema, S. E., Meyer, W. J., Murad, M. H., Rosenthal, S. M., Safer, J. D., Tangpricha, V., & T'Sjoen, G. G. (2017). Endocrine Treatment of Gender-Dysphoric/Gender-Incongruent Persons: An Endocrine Society Clinical Practice Guideline. The Journal of Clinical Endocrinology and Metabolism, 102(11), 3869–3903. [DOI:10.1210/jc.2017-01658]
  • Wiepjes, C. M., den Heijer, M., & TʼSjoen, G. G. (2019). Bone health in adult trans persons: an update of the literature. Current opinion in endocrinology, diabetes, and obesity, 26(6), 296–300. [DOI:10.1097/MED.0000000000000502]