Abstract

Objectives: Androgenetic alopecia (AGA) is a common disorder affecting both men and women, often complicating not only therapeutic decisions but also outcomes in hair transplantation. Recent advances in pharmacogenetics have identified key genetic variants influencing response to mainstay treatments (minoxidil, finasteride, dutasteride). This study aimed to validate a 26-SNP genetic panel for optimising treatment response, adherence, and the condition of potential donor areas, thus providing an adjunctive tool for improving outcomes in both medical and surgical hair restoration. Introduction: Personalised genotyping using a validated 26-SNP panel enables a more precise, evidence-based approach to AGA management, increasing the probability of therapeutic success and adherence. Crucially, such stratification also holds promise for hair transplant candidates, where predicting the stability and responsiveness of the donor area may contribute to better long-term outcomes. These findings support the integration of genetic profiling into both medical and surgical planning for alopecia. Materials / method: Building on a foundational study of over 26,000 anonymised patients, two follow-up cohorts were analysed: 1. A 270-patient retrospective analysis, where treatment decisions were stratified by individual SNP profiles, evaluating overall therapeutic efficacy and adherence over 12 months. 2. A prospective study of 100 patients, in which detailed clinical improvement (including densitometry and physician-rated alopecia scores) was correlated with SNP variants specifically in pathways relevant to minoxidil metabolism (SULT1A1), prostaglandin signalling (PTGFR, PTGDR2), and androgen metabolism Results: Genotype-guided therapy improved adherence (82% vs 62%) and clinical response compared to standard treatment. SULT1A1 and PTGES2 variants significantly predicted minoxidil efficacy (p<0.01), while SRD5A1 and SRD5A2 variants correlated with finasteride/dutasteride response (p<0.05). In both cohorts, patients with favourable vasodilation and androgen profiles showed greater improvement in alopecia scores and preserved donor area density, supporting genetic screening as an adjunct to optimise hair restoration outcomes. Conclusion: Personalised genotyping using a validated 26-SNP panel enables a more precise, evidence-based approach to AGA management, increasing the probability of therapeutic success and adherence. Crucially, such stratification also holds promise for hair transplant candidates, where predicting the stability and responsiveness of the donor area may contribute to better long-term outcomes. These findings support the integration of genetic profiling into both medical and surgical planning for alopecia.