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How To Regulate pH Balance of Your Skin?

How To Regulate pH Balance of Your Skin?

The stratum corneum is referred to as an “acid mantle”. This name is justified by the acidic pH of the hydrolipidic film, which plays an important role in antimicrobial defense and the integrity of the stratum corneum. As a result, a disturbance in skin pH can lead to several unpleasant effects. How to maintain and regulate the pH balance of your skin? Find out in this article what helps your pH balance to stay leveled.

Published February 29, 2024, by Sandrine, Scientific Editor — 10 min read

What Is Skin pH?

The skin is our body's largest organ. It is our body's first line of defense against external aggression. This protective role is made possible by the acidic pH of around 5.5 of the skin's hydrolipidic film. The hydrolipidic film on the skin's surface is a complex emulsion composed essentially of sweat and sebum. The acidic pH of the hydrolipidic film is a key factor in barrier homeostasis, stratum corneum integrity and antimicrobial defense: it's known as the “acid barrier” or “acid mantle”.

Skin pH varies according to both endogenous and exogenous factors. Endogenous factors that can cause pH to vary include the following:

  • Age: the skin pH of newborns is much higher than that of adults, with a value close to 7 (neutral pH), and decreasing with age;

  • Skin zones: Skin pH is higher in certain areas of the body (armpits, groin, intra-mammary area…). In the armpits, a higher pH leads to colonization by certain resident odor-producing bacteria, such as propionic bacteria and staphylococci. Deodorants containing citrates reduce pH and inhibit bacterial activity;

  • Skin type: teenagers with oily, acne-prone skin have a rather alkaline skin pH.

Other endogenous factors, such as gender or skin pigmentation, can also vary the pH. In addition to endogenous factors, exogenous factors can vary skin pH. These include

  • Certain cosmetic products: soaps, for example. Soaps, for example, have a basic pH of around 9 – 10, which disturbs the natural acid pH of the hydrolipidic film, resulting in dry skin and the risk of infection.

Please note: Unlike soaps, which have a basic pH that disrupts the skin's pH, cosmetics with an acidic pH of between 3 and 4, such as vitamin C- or fruit acid-based products, are beneficial for the skin. Their enzymes responsible for ceramides production (lipid constituents of the skin barrier) have an optimal acidic pH. In this way, they help strengthen the skin barrier. But be careful! Some products, such as lemon juice, whose properties are touted on the Internet, have a pH that is too acidic (2.4) and are therefore irritating to the skin.

A skin pH off balance can have unfortunate consequences. It is therefore important to use cosmetic products with a pH between 3 and 7.

The Symptoms of Unbalanced pH Levels.

As a reminder, the skin's acid pH preserves the integrity and cohesion of the stratum corneum and protects the skin from microbial infection. In fact, when skin pH rises, the enzymes responsible for ceramides production, which have an optimal acid pH, are inactivated, compromising the structure and function of the stratum corneum. Moreover, while lipid-synthesizing enzymes decrease, other enzymes increase at acid pH: serine proteases. The latter lead to a reduction in corneodesmosomes, by degradation of desmoglein-1, whose role is to ensure the cohesion of stratum corneum elements.

When the pH of the skin is deregulated, 

the skin is no longer resistant to external 

aggression and does not retain its moisture.

This is conducive to the development of dermatoses such as atopic dermatitis. Indeed, it has been shown that the higher the pH, the more intense the itching and the greater the dryness. In addition to the fact that in atopic dermatitis the structure of the stratum corneum is altered, colonization by Staphylococcus aureus is a common feature of affected patients and is considered a major pathogenic factor in atopic dermatitis. Staphylococcus aureus adhesion to human keratinocytes increases with rising pH.

The growth of protective bacteria in the skin microbiota is optimal at acidic pH levels, whereas pathogenic bacteria thrive at neutral and basic pH levels (Staphylococcus aureus, Cutibacterium acnes). As a result, deregulation of skin pH disrupts the microbiota and prevents antimicrobial protection. This increases the risk of infection. Furthermore, serine proteases, which are activated by high pH, lead to the synthesis of cytokines that cause inflammation.

Preserving the skin's pH is therefore essential to maintaining the integrity of the stratum corneum and the skin's protective role.

How To Regulate pH Balance.

What helps your pH balance to stay in line? First, it's important to wash your skin with a mild cleanser with a pH between 4 and 7. However, you mustn't overdo it, as excessive cleansing weakens the hydrolipidic film and upsets the skin's pH. For this reason, cleanse your skin no more than 2 times a day.

After cleansing, use a toner to restore the skin's pH balance, thanks to a slightly acidic pH. Toning lotions remove the limescale residues present in the water at the time of cleansing, preparing the skin for subsequent treatments. The use of a toner is essential, especially if you use a cleansing soap. Cleansing soaps have a basic pH of around 9 – 10, which disrupts the hydrolipidic film. So, using a toner after soap helps to rebalance the skin's pH. This avoids the risk of infection and weakening of the stratum corneum.

Frequent hand-washing, the use of hydro-alcoholic gel and cleaning products (washing-up liquid, etc.) all upset the skin's pH level, weakening the cutaneous barrier and leading to increased dryness and the onset of dermatitis (eczema, dermatitis, etc.). So, when you have the choice, opt for washing with water and a cleansing oil or soap-free cleanser, rather than using hydro-alcoholic gel. In addition, wear gloves when using cleaning products. Don't forget to moisturize your hands regularly to strengthen the skin barrier and prevent water loss. Our 10-ingredient hand balm moisturizes and nourishes skin with a combination of hyaluronic acid, coconut oil and sunflower oil. Its minimalist, fragrance-free formula is suitable for sensitive skin.

Sources :

  • YOSIPOVITCH G. & al. Skin pH : From basic science to basic skin care. Acta Dermato-Venereologica (2013).

  • CRITON S. & al. Evaluation of pH of bathing soaps and shampoos for skin and hair care. Indian Journal of Dermatology (2014).


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