Management of Hair Loss Associated with Hormone Replacement Therapy

HRT can cause hair loss through various mechanisms, with female pattern hair loss (androgenetic alopecia) being the most common presentation, characterized by diffuse thinning primarily on the crown and with recession of frontal and bitemporal hairlines 1
Hair loss typically develops between 6-18 months after initiating hormone therapy, with histological findings showing miniaturization of hair follicles and decreased anagen-to-telogen ratio 1
In a survey of women receiving aromatase inhibitors, 22.4% reported hair loss and 31.8% reported hair thinning, indicating this is a common concern 1

Diagnostic Approach

Before initiating treatment, rule out other causes of hair loss through laboratory testing including thyroid function (TSH and free T4), iron stores (ferritin), and zinc levels 1

Patient expectations should be managed, as hair regrowth typically begins 2-3 months after starting treatment, with hair growing at approximately 1 cm/month 1

Women should be informed that HRT carries risks including increased risk of venous thromboembolism, CHD, and stroke within the first 1-2 years of therapy, while breast cancer risk increases with longer-term use 3, 4
For patients with hormone-sensitive cancers, systemic hormone therapy should be avoided 2
Transdermal routes of HRT administration should be preferred as they have less impact on coagulation factors 2

Adjusting the HRT regimen, using the lowest effective dose for symptom management while minimizing hair loss, can be an effective approach 2