Previous slide
Next slide

The Scientific Unveiling of Salicylic Acid: How Does It Improve Your Skin Condition?


Salicylic acid, a component widely used in skincare products, may already be familiar to you from various cleansers and creams. But what exactly is salicylic acid? How does it work, and why does it stand out among many ingredients as the preferred choice for treating acne and other skin issues?

This article will delve into the scientific principles of salicylic acid, explaining how it affects the physiological mechanisms of the skin, and why it is a powerful tool for improving your skin condition. We will discuss its chemical properties, its specific actions on the skin, how to use salicylic acid safely, and how to prevent potential side effects. Through a scientific perspective, we aim to enhance your understanding and confidence in salicylic acid and its application in daily skincare.

Basics of Salicylic Acid

1. Chemical Properties

Salicylic acid (chemical formula: C7H6O3), also known as 2-hydroxybenzoic acid, is a compound in the form of colorless crystals or powder. It belongs to the category of β-hydroxy acids (BHA) and is extensively used in skincare products not only for its excellent skin penetration capabilities but also because it can dissolve in fats, effectively clearing clogs in pores.

  • Molecular Structure: Salicylic acid contains a benzene ring, which imparts hydrophobic properties, while the presence of a hydroxyl group (-OH) and a carboxyl group (-COOH) gives it a good balance of lipophilicity and hydrophilicity, allowing it to act effectively in the oily environments of the skin.

2. Physical Form

  • Form Characteristics: At room temperature, salicylic acid is a colorless to white crystalline powder, soluble in alcohol, ether, and other organic solvents, and slightly soluble in water.

3. Solubility

  • Solubility in Water: Salicylic acid has relatively low solubility in water, which allows it to stay on the skin surface and not be washed away easily, enhancing its deep cleansing action.
  • Solubility in Fats: Its high lipophilicity enables salicylic acid to penetrate the skin surface and enter the pores.

4. Origin and History

  • Natural Sources: Salicylic acid was originally extracted from the bark of willow trees, hence its name. It has a long history of use in traditional medicine for its anti-inflammatory and antipyretic properties.
  • Synthetic Pathways: Modern industrial production of salicylic acid primarily involves the chemical reaction of phenol with carbon dioxide, a method known as the Kolbe-Schmitt synthesis.

Mechanism of Action of Salicylic Acid

Skin Absorption Process

  1. Pore Penetration:
    • Epidermal Action: Salicylic acid first acts on the outermost layer of the skin—the epidermis, particularly the stratum corneum. Due to its lipophilicity, salicylic acid can penetrate between the lipid cells of the stratum corneum, reaching deeper skin layers.
    • Sebaceous Glands: It further penetrates into the follicles and sebaceous glands, key areas for combating acne. By entering these areas, salicylic acid directly targets the source of problems—excess oil in the pores.
  2. Chemical Properties Assist Absorption:
    • Lipophilicity: The lipophilic nature of salicylic acid allows it to act effectively in lipid-rich areas (such as the face), explaining why it is particularly suitable for treating oily and combination skin types with acne.
    • Keratolytic Ability: Salicylic acid can dissolve the ‘glue’ (mainly composed of lipids) between cells in the stratum corneum, not only helping it penetrate deeper skin layers but also facilitating the shedding of old keratinocytes, creating space for new cell growth.

Biochemical Reactions

  1. Anti-inflammatory Action:
    • Reduction of Inflammatory Mediators: Salicylic acid reduces the production of inflammatory mediators like prostaglandins by inhibiting certain enzyme activities, thereby alleviating skin redness and pain.
    • Cell Signaling Regulation: It modulates intracellular signaling, affecting cytokine expression, which is another mechanism by which it reduces inflammation.
  2. Promotion of Stratum Corneum Shedding:
    • Desquamation of Keratinocytes: Salicylic acid promotes the desquamation of keratinocytes in the stratum corneum, accelerating their natural shedding process. This not only helps clear clogged pores of dead skin cells but also reduces the space for bacterial growth, effectively preventing the occurrence of acne.
    • New Cell Generation: By
    accelerating the shedding of old cells, salicylic acid promotes the generation of new cells, which is crucial for repairing acne scars, reducing fine lines, and other signs of skin aging.
  3. Bacterial Growth Inhibition:
  • PH Adjustment: The acidic nature of salicylic acid can lower the pH value on the skin surface, inhibiting the growth of certain pathogenic bacteria (especially those associated with acne), which is an important aspect of its anti-acne effects.
Explore the benefits of salicylic acid for skin care in this detailed guide. Learn about its chemical properties, how it penetrates pores to treat acne, its exfoliating benefits, and its use in preventing acne scars and aging signs. Find out how to safely apply salicylic acid, its side effects, and tips for effective use with moisturizers and sun protection. Gain insights on choosing the right concentration for your skin type and the scientific mechanisms behind its skin-enhancing capabilities.

Applications of Salicylic Acid in Skincare

Fighting Acne

Action Mechanism:

  1. Deep Pore Cleansing
    • Dissolving Fats: Salicylic acid can penetrate pores, dissolving the fats and other impurities that clog them, which is its most direct action against acne.
    • Clearing Dead Skin Cells: By softening and dissolving the dead cells of the stratum corneum, salicylic acid helps prevent pores from being blocked again.
  2. Anti-inflammatory Action
    • Reducing Swelling: Salicylic acid has anti-inflammatory properties that can reduce the swelling and inflammation caused by acne.
    • Quick Acne Treatment: It is commonly used for the treatment of mild to moderate acne, particularly effective against blackheads and whiteheads.

Application Forms:

  • Cleansing Products: Salicylic acid-containing cleansing milks or foams can be used for daily cleaning, helping to keep pores clear.
  • Topical Treatment Creams: For specific acne areas, using topical treatment creams can directly affect the problem area, accelerating healing.
  • Masks and Facial Skincare: Periodic use of salicylic acid-containing masks can deeply clean the skin, preventing the formation of acne.

Exfoliation and Anti-aging

Action Mechanism:

  1. Promoting Cell Renewal:
    • Accelerating Cell Turnover: By removing aged skin cells, salicylic acid promotes the generation of new cells, which helps improve the overall texture and appearance of the skin.
    • Reducing Fine Lines and Wrinkles: The generation of new cells can also help reduce the fine lines and wrinkles on the epidermis, providing a younger look.
  2. Improving Uneven Skin Tone:
    • Removing Pigmentation: Salicylic acid can help lighten pigmentation caused by acne scars or excessive sun exposure, evening out the skin tone.

Application Forms:

  • Day and Night Skincare Products: Salicylic acid-containing day creams or night creams can be used for daily skincare, helping with exfoliation and anti-aging.
  • Chemical Peels: Professional chemical peels use higher concentrations of salicylic acid for deep skin renewal treatments, suitable for more severe skin aging issues.

Safe Guidelines for Using Salicylic Acid

Correct Usage Methods

  1. Choosing the Appropriate Concentration:
    • For beginners or those with sensitive skin, it is recommended to use products containing low concentrations of salicylic acid (such as 1%-2%).
    • For treating acne and deep cleansing, concentrations up to 2% may be used, but it is best to do so under medical supervision.
  2. Performing a Skin Test:
    • Before using a new product, perform a small-scale skin test on the inside of the arm or behind the ear to check for any allergic or irritant reactions.
    • Wait 24 hours; if there is no adverse reaction, it can generally be used safely.
  3. Correct Application Method:
    • After cleaning the skin, gently apply the salicylic acid product with fingertips to the targeted area, avoiding rubbing the skin.
    • Unless otherwise directed by the product instructions, do not apply multiple layers of product to the same area.
  4. Usage Frequency:
    • When starting with salicylic acid, begin using it 1-2 times a week, gradually increasing to once daily to allow the skin to adapt.
    • Monitor skin response; if excessive dryness or irritation occurs, reduce the frequency of use.
  5. Combining Moisturization and Sun Protection:
    • After using salicylic acid products, use moisturizing products to avoid excessive dryness of the skin.
    • During the day, it is essential to use a sunscreen with an SPF of 30 or higher, as salicylic acid can make the skin more sensitive to sunlight.

Possible Side Effects

  1. Skin Irritation and Rash:
    • The most common side effect of using salicylic acid is skin irritation, which may manifest as a rash, itching, or burning sensation.
  2. Excessive Dryness and Peeling:
    • The exfoliating action of salicylic acid may cause temporary dryness and peeling of the skin, especially when starting use.
  3. Increased Photosensitivity:
    • Sal

icylic acid can increase the skin’s sensitivity to sunlight, making it more prone to sunburn.

  1. Allergic Reactions:
    • Although uncommon, some people may be allergic to the salicylic acid ingredient, manifesting as severe rashes, swelling, or irritation.


After a comprehensive exploration of salicylic acid, from its chemical properties and mechanisms of action to safe usage guidelines, we can see that salicylic acid is not only a potent skincare ingredient but also versatile in addressing various skin issues. Through this article, we hope readers have gained a better understanding of the scientific principles behind salicylic acid and learned how to use this ingredient effectively and safely to improve skin conditions.

Leave a Comment

Your email address will not be published. Required fields are marked *