When the summer breeze blows over the skin, many people will unconsciously reach out and touch their legs and armpits, wondering which way to say goodbye to their body hair. In the blue light of beauty instrument, the smell of depilatory cream and the buzz of laser instrument, a tug-of-war about hair quietly started. But in this battle, are we fighting against the hair itself, or are we driven by some ideas to compete with our bodies? More importantly, is hair removal really as simple and harmless as it looks?
The thick or sparse hairs on the skin surface are actually the external appearance of the "hair follicle ecosystem" carefully arranged by the body. Hairy mother cells are hidden in the depths of hair follicles. They are very dynamic members of the stem cell family and participate in skin regeneration and repair. Every hair growth is the result of subtle cooperation between hair follicles and skin, sebaceous glands and sweat glands. For women, there are about 140,000 hair follicles in the legs and 1,000 to 1,500 hair follicles in the armpits. These seemingly tiny hair follicles maintain the micro-environment balance of local skin.
Physical hair removal, such as shaving knife and wax paper, seems to be simply and rudely pulling out or shaving off hair, but in fact it will bring tiny stimulation to hair follicles. When the razor is scratched on the skin surface and operated along the hair growth direction, the sharp blade will accurately cut the keratin structure of the hair, but if it is not operated properly, it will be taken away together with the cuticle of the epidermis, resulting in tiny wounds that are hard to see with the naked eye, giving bacteria an opportunity to invade. The data shows that about 30% of women will have different degrees of skin redness and itching after using the hair scraper. This is not an allergic reaction, but a signal that the micro-ecology around the hair follicle is temporarily destroyed. The wax paper for hair removal can uproot the hair at the moment of tearing, but it also breaks the tiny nerve endings around the hair follicle. Long-term frequent use will make the connection between the hair follicle and the skin loose and affect the normal nutritional circulation of the hair follicle.
The principle of chemical depilatory is more complicated. It relies on chemical components such as calcium thioacetate to penetrate hair, destroy the disulfide bond structure inside hair, and make the original tough hair loose and easy to fall off. However, these chemicals can not always accurately identify hair, and they will act on the stratum corneum in a small part, changing the water content and pH value of the stratum corneum. The pH value of normal skin is between 5.0 and 5.6, but the local pH value can rise to 6.5 or even higher after using chemical depilatory, and the skin barrier function is weakened. After using it for people with sensitive skin, the skin dryness and desquamation will increase obviously.
Laser hair removal, as a popular "long-lasting" hair removal method, its operating mechanism is that the melanin in hair follicles is precisely acted on by laser with a specific wavelength, generating heat energy to inactivate hair follicles. Ideally, it can inhibit hair follicle growth. However, the growth cycle of human hair follicles includes growth period, regression period and rest period, and laser hair removal can only work on hair follicles in growth period. This means that multiple treatments are needed to achieve the whole body hair removal effect. Every time the laser is operated, the internal microcirculation system of hair follicle will undergo an "emergency test" under the impact of thermal energy, and the metabolic rate of some hair follicle cells will be accelerated. After long-term repeated stimulation, the permeability of microvascular wall around hair follicle will increase, which is easy to cause local skin pigmentation. In clinic, 5% to 8% of beauty seekers have skin pigmentation problems after laser hair removal.
In fact, the existence of body hair is not meaningless. It can sense the change of weak airflow and assist the human body to judge the ambient wind speed; When the skin encounters slight friction, it plays a buffering and protecting role. Those seemingly tiny hairs are the "microscopic tentacles" for us to interact with the external environment. Excessive pursuit of hairless state may inadvertently cut off the natural connection between the body and nature. Perhaps, the next time we stand in front of the mirror, we can look at these hairs in a different way. They are not just beautiful "encumbrances", but an elaborate part of the body, which is closely related to our health.
