A Randomized Controlled Trial of the Efficacy and Safety of 1565nm Non-ablative Fractional Laser on Treating Androgenic Alopecia

1. Androgenic alopecia (AGA) is a clinically common non cicatricial, progressive hair follicle microminiaturization disorder that begins in puberty or after puberty. The latest epidemiological survey shows that the prevalence rate of males in China is about 21.3%. In 2021, Nature published an article stating that stress hormones can inhibit hair growth by regulating hair follicle stem cells. This research conclusion provides new evidence for the impact of stress on hair growth. The trend of receiving AGA patients in the investigators' outpatient department is increasing. How to provide rapid, safe, and effective treatment for AGA patients is currently a hot topic for clinicians.
2. Studies have shown that phototherapy can effectively improve androgenic alopecia, alopecia areata, and hair loss after chemotherapy, and promote hair growth. At the same time, phototherapy can also be adjusted by adjusting the expression of reductase genes and vascular endothelial growth factor genes, as well as some endogenous epidermal growth factors, such as fibroblast growth factor and insulin-like growth factor, are also upregulated, which can stimulate hair growth.

3.1565 nm non-ablative fractional laser has the effects of inhibiting sebaceous gland secretion of oil, regulating collagen metabolism, and delaying changes in scalp collagen after hair loss. Previous studies have confirmed that 1565 nm non-ablative fractional laser therapy for alopecia areata has a good effect. Its possible mechanisms include increasing local blood flow, stimulating growth factors and cytokines during hair growth. At the same time, in order to achieve low energy, safe, and effective treatment without the need for hair cutting, the investigators had for the first time improved the 1565 nm non non-ablative fractional laser treatment tool, removing the original sapphire crystal cooling contact. This improvement can make the treatment head fully fit the scalp, and the excitation beam acts vertically on the treatment area, reducing energy attenuation.