Hair Growth Promoting Effects of 650 nm Red Light Stimulation on Human Hair Follicles and Study of Its Mechanisms via RNA Sequencing Transcriptome Analysis

In 2021, researchers found that 650 nm red light stimulation promoted hair growth and inhibited hair loss in human hair follicles. The study used RNA sequencing transcriptome analysis to understand the underlying mechanisms, revealing that the red light led to the upregulation of genes associated with hair growth and downregulation of genes related to hair loss. The study also found that 650 nm red light delayed the transition of hair cycle from growth phase to degradation phase in vitro. The research suggested that biological processes such as leukocyte transendothelial migration, metabolism, and adherens junction may be involved in the stimulation of hair follicles by 650-nm red light treatment. The results supported the use of low-level laser therapy in the treatment of androgenetic alopecia, a common form of hair loss.