Purpose: Prostaglandins play a pivotal role in modulating hair growth cycle. Prostaglandin F2α and prostaglandin E have stimulating and prostaglandin D has inhibitory effects on hair follicle. Cetirizine inhibits release of prostaglandin D2 and stimulates the release of prostaglandin E2. In the present study, the efficacy and safety of twice daily application of topical cetirizine 1% versus minoxidil 5% solutions for 16 weeks were compared in male androgenetic alopecia (AGA).
Methods: Forty men, aged 18 to 49 years, were randomly divided into two equal groups to apply either cetirizine 1% or minoxidil 5% solutions. The study was divided into two phases, a 16-week treatment phase either with cetirizine or minoxidil (anagen phase), followed by an 8-week drug-free (telogen phase) with a follow-up when patients used placebo. Efficacy outcomes included the change in total hair density, vellus and terminal hair density, hair diameter and the percentage of hair in anagen and telogen phases from baseline in 16 and 24 weeks.
Results: After 16 weeks, we observed a significant increase in total and vellus hair density in both minoxidil and cetirizine groups, but the improvement was much higher in the minoxidil group. The percentage of hair in the anagen phase also increased in both groups after 16 weeks of treatment, but then diminished after 8 weeks of placebo consumption. No significant adverse reactions associated with the administration of cetirizine solution were reported.
Conclusion: Cetirizine 1% solution was effective in hair growth without any complications for treatment of male AGA.