A decade of hair-loss clinical trials: a registry-based analysis of studies registered on ClinicalTrials.gov.

BACKGROUND

ClinicalTrials.gov captures registered hair-loss trials across the full research lifecycle, including ongoing, discontinued, and unpublished studies. We used this registry to describe how the hair-loss clinical trial landscape has evolved from 2015 to 2025, focusing on trial volume, geography, indications, intervention types, outcome assessment, and sponsorship.

METHODS

We conducted a descriptive cross-sectional meta-research analysis of hair-loss-related interventional studies registered on ClinicalTrials.gov (2015-2025). Trials were categorized by recruitment status, country/region, sex, and age eligibility, primary indication, intervention modality, primary outcome assessment approach, and sponsor type. We summarized distributions and temporal trends using descriptive statistics.

RESULTS

We identified 514 hair-loss trials, with registrations increasing over time, particularly after 2020. Activity was global but concentrated in select regions, especially North America, and most trials were completed or recruiting. Androgenetic alopecia and alopecia areata predominated; pharmacologic therapies were most common overall, with greater therapeutic diversity in androgenetic alopecia. Outcome reporting was heterogeneous, objective imaging was infrequent, and sponsorship was divided between industry and academic/non-profit institutions.

DISCUSSION: This registry-based analysis nevertheless delineates a rapidly expanding yet structurally uneven landscape of hair-loss clinical research, marked by geographic concentration, therapeutic clustering, and variability in outcome specification. By systematically mapping trial activity, indications, modalities, sponsorship, and completion patterns, the study reframes attention from individual therapies to the broader architecture of evidence production. These findings underscore the need for standardized outcomes, broader population representation, and closer alignment between research investment and clinical need in hair-loss disorders.