Therapeutic effects of topical cetirizine in the treatment of female pattern hair loss: a randomized controlled noninferiority trial

Female pattern hair loss (FPHL) is the most prevalent form of hair loss in women. It was aimed to evaluate the therapeutic effects of topical cetirizine 1%, versus topical minoxidil 2% in patients with FPHL. Through a triple-blind randomized clinical trial, 60 women with FPHL were randomly divided into two groups of treatment with topical cetirizine 1% or topical minoxidil 2%. The endpoint was changing in hair loss severity as well as terminal hair density and diameter, according to trichoscopic evaluation. Intention-to-treat analysis was also performed for those who accomplished 3 months of treatment. Both groups showed improvement in hair diameter and density after 6 months; however, the outcome was significant only in the minoxidil group. According to per-protocol analysis, minoxidil was significantly superior to cetirizine in hair density, but not in hair diameter. According to the hair loss severity scales, FPHL was significantly improved in both the cetirizine and minoxidil groups after 6 months of therapy. The dropout rate due to adverse effects was 10.0% and 6.6% in the cetirizine and minoxidil groups, respectively. Although inferior to topical minoxidil, topical cetirizine can provide favorable therapeutic effects for FPHL, specifically when patient incompatibility with Minoxidil is observed. The study is registered in the Iranian Registry of Clinical Trials (IRCT) with the registration code IRCT20200521047536N1.