Hair removal is one of the most popular cosmetic procedures. For the procedure for removing unwanted hair, lasers turned out to be the most effective, allowing for several sessions to solve this problem forever, without the risk of its reappearance. The key advantages of the laser procedure over traditional methods are:
Already after the first procedure of laser hair removal, the result is noticeable and with each subsequent session the hair becomes less and less frequent until it disappears completely. Modern laser systems make it easy to remove hair of any type, even on the most sensitive skin areas. The high pulse repetition rate and the large area of the zone treated in one flash allow to reduce the procedure time.
Melanin is the main chromophore (a substance that absorbs radiation energy) for all types of lasers. Thus, the essence of the procedure lies in the selective effect of laser radiation on follicles in the anagen stage (active growth), which accumulate a large amount of melanin. Under the influence of a laser beam in the follicle, the radiation energy is converted into heat, which leads to overheating and cell death. Due to the short pulse duration, the tissues adjacent to the follicle are not damaged.
However, despite all the effectiveness of modern laser technologies, the question of the effect of a laser on patients with dark skin remains open and highly relevant. Patients with dark skin (IV-VI phototype), as well as severely tanned patients, as a result of the laser hair removal procedure, risked the appearance of depigmented areas on the skin, and in some cases even getting a burn. This happens because the excess melanin in such people is contained not only in the follicles, but directly in the skin cells. For a long time it was believed that hair removal was impossible for such patients.
In modern cosmetology, laser devices of the following types are most often used for laser hair removal: ruby (694 nm), alexandrite laser (755 nm), diode (808 nm) and neodymium (1064 nm).
The use of a ruby laser for hair removal on dark skin is highly discouraged due to the high risk of burns. The wavelength of the alexandrite laser is longer than the ruby laser, which expands its scope, but the likelihood of burns remains, especially for V-VI skin phototypes. The diode laser, despite the longer wavelength than the alexandrite laser, is unfortunately even less suitable for hair removal on dark skin due to its low photoselectivity (diode lasers are not lasers in their pure form and occupy an intermediate position between lasers and broadband light sources e.g. IPL).
The most suitable tool for hair removal on dark skin is a neodymium laser with a wavelength of 1064 nm. Its long-wavelength radiation is poorly absorbed by melanin, and therefore poorly absorbed by skin cells. Such radiation does not lead to the appearance of light spots and certainly does not cause burns. But how does it then destroy the follicles?
The chromophore of the neodymium laser is oxyhemoglobin, which is contained in the blood of the capillaries feeding the bulb. However, having solved the issue of hair removal on dark skin, this approach created a new problem – the risk of damage to the vessels supplying the dermis. Therefore, in order to avoid side effects, it is necessary to strictly control the radiation penetration depth, which is achieved with new generation neodymium lasers.
The optimal choice for laser hair removal is the Nd: YAG Dynamic solid state neodymium laser. Its beam penetrates the epidermis to a safe depth, ensuring that the light energy reaches the hair follicle and the vessels feeding it precisely.
Thus, the introduction of modern laser technologies in cosmetology has made an effective and comfortable laser hair removal procedure available for patients with any skin phototype, at any time of the year, regardless of the degree of sunburn.