Comparison of Salicylic Acid, Lactic Acid and Glycolic Acid
Recently, skin care has attracted much attention. Salicylic Acid, Lactic Acid and Glycolic Acid are quite common in the field of skin care. Each has its own characteristics and different effects. Today, we will compare them in detail.

1. Chemical Properties
Salicylic acid is a beta-hydroxy acid. Its molecular structure contains a benzene ring and has fat-soluble characteristics. This property allows it to penetrate deep into the pores of the skin and reach the secretion of sebum. Lactic acid is an alpha-hydroxy acid, which is fermented from lactose. It is a water-soluble acid with relatively small molecules and can penetrate into the surface of the skin quickly. Glycolic acid is also an alpha-hydroxy acid, which is the smallest alpha-hydroxy acid and has good water solubility. Because of its small molecules, it has a particularly strong penetration and can quickly act on the skin.

Second, the effect on the skin
1. ** Salicylic acid **: Because of its fat solubility, it can effectively remove the oil and keratin accumulated in the pores. It is a good medicine for oily skin with frequent acne and acne. It can penetrate deep into pores, dissolve corneal suppositories, prevent acne formation, and has a certain anti-inflammatory effect, which can relieve the redness and swelling of acne skin.
2. ** Lactic acid **: In addition to exfoliating effect, it can increase the skin's moisturizing ability. Because it is one of the natural moisturizing factors, it can make the skin soft, smooth and hydrated after use. Suitable for dry, dehydrated skin with mild exfoliation.
3. ** Glycolic acid **: The exfoliating effect is significant, which can accelerate the skin's metabolism, promote the shedding of old waste exfoliation, and allow the skin's new cells to appear on the surface faster. It is often used to improve the dullness, roughness and fine lines of skin tone, and restore the skin's luster and elasticity

3. Applicable skin type
1. ** Salicylic acid **: It is very suitable for oily, mixed and acne-prone skin. However, because of its certain irritation, sensitive skin needs to be used with caution. If used improperly, it is easy to cause skin redness and tingling.
2. ** Lactic acid **: It is more suitable for dry and sensitive skin. Because it is relatively mild, it can both exfoliate and moisturize, and it is not easy to cause skin discomfort. However, if the concentration is too high, it may also cause irritation to some sensitive skin.
3. ** Glycolic acid **: Neutral, oily and anti-aging skin can be tried. However, high-concentration glycolic acid is highly irritating. First-time users should try it locally first, and sensitive skin must be used with caution.

IV. Precautions for use
1. ** Salicylic acid **: When using, you should start from a low concentration to gradually establish skin tolerance. Avoid using it at the same time with other irritating products, and you need to strengthen sun protection after use, because salicylic acid may make the skin more sensitive to ultraviolet rays.
2. ** Lactic acid **: Although relatively mild, the frequency of use should not be too high to avoid excessive exfoliation and damage to the skin barrier. Moisturizing and sun protection should also be done after use.
3. ** Glycolic acid **: When using high-concentration glycolic acid products, it is best to carry out under the guidance of a professional. During use, the skin may experience temporary tingling, redness and other phenomena. If the symptoms are serious, stop using it immediately and seek professional help. At the same time, daily sun protection is indispensable to prevent the skin from being damaged by ultraviolet rays due to accelerated metabolism.

To sum up, salicylic acid, lactic acid and glycolic acid have their own advantages. When taking care of the skin, you should carefully choose the appropriate acid products according to your skin type and needs, so as to achieve the ideal skin care effect and make the skin glow.