Tailoring transdermal estradiol dose to maximize benefits and minimize risks.

Transdermal estradiol is licensed to treat estradiol deficiency symptoms and prevent osteoporosis in postmenopausal women. There is no one-size-fits-all estradiol dose or serum concentration that will achieve symptom relief and bone protection in all women. Dose is usually titrated to symptom response, but measurement of serum estradiol concentration can be used to support or inform dose decisions in certain clinical scenarios. The optimal level for an individual varies according to tissue sensitivity (pharmacodynamic effects), the method used for estradiol quantitation (immunoassay vs. mass spectrometry), the clinical endpoint (symptoms vs. bone protection), and treatment goals, including patient preferences. An understanding of transdermal estradiol pharmacokinetics and pharmacodynamics, and the limitations of the methods used to measure serum estradiol, is essential to ensure that all women who choose to use menopausal hormone therapy (MHT) can reap the benefits and avoid the harms of over-treatment and under-treatment. Achieving and maintaining optimal estradiol levels for all MHT users is consistent with menopause guidelines that promote high-quality, patient-centred, personalized menopause care.