Promotion of Anagen, Increased Hair Density and Reduction of Hair Fall in a Clinical Setting Following Identification of FGF5-inhibiting Compounds Via a Novel 2-stage Process

Background: There are very few effective, scientifically validated treatments with known mechanisms of action for treatment of hair loss in both men and women. Fibroblast growth factor 5 (FGF5) is an important factor in the irreversible transition from anagen to catagen, and inhibition of FGF5 prolongs anagen phase and reduces hair loss.

Objective: We aimed to screen botanically derived molecules for FGF5 inhibitory activity in vitro and assess efficacy in a clinical setting.

Methods: We screened for FGF5 inhibitory efficacy via a novel 2-step in vitro pipeline consisting of an engineered FGF5 responsive cell line, followed by an activated dermal papillae (DP) cell method. Efficacy in a clinical setting was assessed in a randomized, single-blind, placebo-controlled trial against early- to mid-stage pattern hair loss in men and women.

Results: We observed FGF5 inhibitory activity for a number of compounds from the monoterpenoid family, many showing greater inhibitory efficacy than our previously reported crude plant extracts. Evaluation of a lead candidate in a clinical study over 112 days showed a significant improvement in anagen:telogen (AT) ratio ( = 0.002), reduced hair fall ( = 0.007) and improved visual grading ( = 0.004). Scientifically matched photography on a subgroup of randomly chosen participants highlighted significant improvement in hair density, with increases evident in all tested participants compared to baseline.

Conclusion: Isolates from the monoterpenoid family displayed efficacy in FGF5 inhibition in vitro. A topical formulation containing a leading isolate significantly improved AT ratio, reduced hair fall and increased apparent hair density in the tested population of men and women.