Blue Light Stimulatory Effect on Hair Growth Mediated by Opsin and Cryptochrome Photoreceptors

The study from May 1, 2018, explored the impact of blue light on hair growth, specifically through the role of Cryptochrome 1 (CRY1) and Opsins 2 and 3 (OPN3) receptors in human hair follicles. It was found that these receptors are present in hair follicles and that blue light at 3.2J/cm² can extend the growth phase of hair follicles ex vivo. Inhibiting CRY1 or OPN3 led to decreased cell proliferation in the outer root sheath keratinocytes. Gene expression analysis revealed that blocking these receptors altered genes involved in cell growth and death. Blue light treatment increased CRY1 protein levels and keratinocyte metabolic activity and proliferation, which was hindered by OPN3 inhibition. The results indicate that blue light positively influences hair growth by interacting with CRY1 and OPN3 receptors.