Poor Therapeutic Response in Female Pattern Hair Loss: Mechanisms and a Practical Framework for Clinical Management.

BACKGROUND: Female pattern hair loss (FPHL) is the most common cause of hair loss in women, yet therapeutic responses remain highly variable. A substantial proportion of patients experience persistent hair thinning or limited hair density improvement despite standard therapies, and current guidelines provide limited guidance for managing patients with poor therapeutic response. SUMMARY: This review summarizes the major determinants of poor therapeutic response in FPHL, including pharmacogenetic factors, metabolic and endocrine comorbidities, treatment-related barriers, and advanced follicular miniaturization. Emerging evidence suggests that androgen receptor (AR) polymorphisms may influence antiandrogen responsiveness, whereas sulfotransferase (SULT1A1) activity may affect topical minoxidil efficacy. Obesity-related insulin resistance and polycystic ovary syndrome may further impair the follicular microenvironment through hyperandrogenism and chronic inflammation. Based on current evidence, we propose a practical three-step framework for evaluating poor responders: exclusion of pseudo-nonresponse, identification of metabolic-endocrine comorbidities, and incorporation of emerging biomarkers to support individualized treatment selection. KEY MESSAGES: Poor therapeutic response in FPHL is multifactorial. Identifying the dominant contributing factor rather than simply escalating treatment intensity may facilitate precision management and improve outcomes in refractory patients.