INTERNATIONAL JOURNAL OF BIOMEDICINE http://dx.doi.org/10.21103/Article12(2)_OA12 International Journal of Biomedicine 12(2) (2022) 269-272 ORIGINAL ARTICLE Dermatology Erbium YAG Laser in the Treatment of Androgenetic Alopecia Fatima V. Azimova 1 , PhD, ScD; Rustam R. Zakirov 1* ; Iroda B. Nurmatova 2 , PhD 1 Center for the Development of Professional Qualifcation of Medical Workers 2 Tashkent Medical Academy, Tashkent, Uzbekistan Abstract The article presents data on the effectiveness of the 2940 nm wavelength erbium-doped yttrium aluminum garnet laser (Er:YAG) in the treatment of androgenetic alopecia (AA) in 85 men. All AA patients underwent a video trichodermatoscopy examination of the scalp using an Aramo-SG video camera (Korea) with ×60 and ×200 lenses, and the Trichoscience diagnostic program. The results of the study were evaluated by videotrichodermatoscopy by the presence of atrophied HF before and after 3 months of laser therapy. A 3-month erbium laser treatment using a 2940-nm Er:YAG laser along with the conventional therapy showed a high effciency, which was expressed in a decrease in microfbrosis around the hair follicles and an increase in hair growth in the anagen stage. (International Journal of Biomedicine. 2022;12(2):269-272.) Key Words: androgenetic alopecia • erbium laser • microfbrosis • trichoscopy For citation: Azimova FV, Zakirov RR, Nurmatova IB. Erbium YAG Laser in the Treatment of Androgenetic Alopecia. International Journal of Biomedicine. 2022;12(2):269-272. doi:10.21103/Article12(2)_OA12 Abbreviations AA, androgenetic alopecia; EL, erbium laser; HF, hair follicles. Introduction One of the most common causes of hair loss is androgenetic alopecia (AA), which dramatically reduces the quality of life, since the awkward appearance can lead to psychological maladaptation. According to some authors, up to 70% of men and 40% of women experience AA. AA is a progressive baldness caused by the action of androgens on the hair follicles. (1,2) The main reason for the development of AA is the activation of the androgen receptor, resulting in a shortening of the anagen, or growth phase, in the normal hair-growth cycle. Circulating free testosterone either binds to intracellular androgen receptors in the hair bulb and dermal papilla (3-5) or is metabolized to dihydrotestosterone by the enzyme 5-α-reductase. (6) In recent years, lasers and various light sources have been widely used in medicine, in particular in dermatocosmetology. It is well known that Low Level Laser Therapy and the 1550 nm Erbium Glass Fractional Laser are highly effective in treating all forms of hair loss by stimulating hair follicles. But today, we also have the 2940 nm wavelength erbium-doped yttrium aluminum garnet (Er:YAG) laser, which is able to penetrate into the dermis to a depth of 3-4 mm, and energy absorption occurs in the area of the dermal papilla, resulting in an increase in blood circulation of the papilla and activation of metabolism in the hair follicle. (7-9) Effects of using the 2940 nm wavelength Er:YAG in AA: (10-12)  Activation of mitosis, proliferation in the cells of the hair follicles, which leads to a lengthening of the anagen phase and the growth of new hair.  Resorption of microfbrosis of hair follicles (HF) because EL generates radiation in the form of microfractional “columns” that penetrate the dermis and cause tissue heating, which leads to a powerful anti-infammatory effect and a decrease in fbrosis of the scalp skin. The epidermis receives minimal damage, which disappears after a few days and which is one of the indisputable *Corresponding author: Rustam R. Zakirov. Center for the Development of Professional Qualifcation of Medical Workers, Tashkent, Uzbekistan. E-mail: dr.tourist@mail.ru