On the feasibility of using glycolic acid twice a week
Whether it is feasible to use glycolic acid twice a week or not, it is necessary to study its properties and the response of the skin in detail. Glycolic acid belongs to the class of fruit acids, which have a lot of functions on the skin.

Looking at its efficacy, one can exfoliate. For keratin, the old cells accumulated on the outer layer of the skin are also. Glycolic acid can loosen the adhesion between them, causing the old keratin to fall off, making the skin surface smooth and delicate, and radiant. Second, it can promote the production of collagen. The elasticity of the skin depends on the support of collagen. Glycolic acid can stimulate fibroblasts, which in turn promotes the regeneration of collagen, making the skin firm and reducing fine lines. Third, it can increase the permeability of the skin. After exfoliation, the skin's ability to absorb nutrients in skin care products is enhanced, and subsequent skin care is twice as effective.

However, it is also strong and irritating. Those with delicate skin are prone to discomfort if used improperly. If the concentration is too high or the frequency of use is too frequent, it can cause redness, tingling and desquamation of the skin. Beginner users have weak skin tolerance and need to be more cautious.

As for the feasibility of using it twice a week, when your mileage may vary. Those with strong skin tolerance, if they have gone through the adaptation stage of low-concentration glycolic acid, can tolerate it twice a week. In this process, the skin gradually adapts to its stimulation, and can continue to reap the benefits of its effects, such as regular exfoliation, and the skin becomes better. However, those with weak tolerance, especially sensitive skin, twice a week or too frequently. Such skin barrier is weak, and glycolic acid stimulation can easily lead to aggravation of barrier damage, causing allergies and other diseases.

In summary, whether glycolic acid is feasible to use twice a week or not, the first priority is skin tolerance. Before use, check the skin type carefully, starting from low concentration and low frequency, and gradually. When using, if the skin is uncomfortable, adjust it in time, or stop or reduce the frequency concentration to ensure skin health.