Effect of Applying Lactiplantibacillus Plantarum Subsp. Plantarum N793 to the Scalps of Men and Women with Thinning Hair: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study

This study investigated the effects of applying Lactiplantibacillus plantarum subsp. plantarum N793 on the scalps of 104 participants with thinning hair over 24 weeks. It was a randomized, double-blind, placebo-controlled, parallel-group trial. Overall, there were no significant differences in hair density between the N793 and placebo groups. However, participants with mild thinning hair showed significantly better hair density in the N793 group compared to the placebo group. Additionally, both groups showed significant improvements in hair density, mean hair diameter, and hair growth coefficients compared to pre-application levels, with the N793 group having a significantly higher telogen hair density after 24 weeks. The study suggests that N793 may be effective in improving hair density in cases of mild hair thinning, potentially by stimulating hair follicle dermal papilla cells and promoting keratinocyte growth factor production. Further research is needed to understand the underlying mechanisms and broader applicability of N793.