Topical Cetirizine in Androgenetic Alopecia: A Preliminary Study

This preliminary study investigated the effects of topical cetirizine on androgenetic alopecia (AGA) in 10 men over 16 weeks. Cetirizine, known for reducing prostaglandin D2 and its anti-inflammatory properties, was applied daily. Nine participants completed the study, showing a significant increase in mean hair count from 139.6 to 163.4 (p = 0.009). Blinded photographic assessments showed varying degrees of improvement, and trichoscopic counts improved in all patients. No adverse events were reported. The study suggests cetirizine as a potential AGA therapy, but larger, longer-term studies are needed to confirm its efficacy and mechanism.