WHAT IS THE pH LEVEL?
The pH value describes the acid-base balance of a solution and indicates how acidic or basic it is. It is measured on a scale from 0 to 14, with 7 being neutral; values below 7 are considered acidic, and values above 7 are considered basic or alkaline. The skin typically has an acidic pH between 4.1 and 5.8—this is known as the skin’s physiological pH. A stable, acidic pH promotes the activity of important enzymes in the skin that are responsible for skin cell renewal and maintaining the skin barrier. It also supports the function of the hydrolipid film, also known as the acid mantle. The hydrolipid film consists of a mixture of sebum, sweat, and dead skin cells and protects the skin from environmental influences, bacteria, and dehydration.
THE IMPORTANCE OF pH FOR THE SKIN MICROBIOME
The skin’s pH level is essential for the function of the acid mantle, which not only protects the skin barrier but also regulates the microbiome. An acidic pH level (4.0 to 5.8) supports the growth of beneficial bacteria such as Staphylococcus epidermidis and Cutibacterium acnes, which contribute to the production of antimicrobial peptides. These keep harmful microorganisms in check and prevent infections. If the pH rises above 7, the balance is disrupted, and pathogenic bacteria such as Staphylococcus aureus can grow more easily. A stable, acidic pH promotes skin renewal, strengthens the barrier function, and protects against inflammation and infections.
THE ROLE OF pH IN SKIN HEALTH
The acid mantle is more than just a barrier. It is a sophisticated buffer system in the outermost layer of the skin that, by maintaining an acidic environment, promotes the skin’s structural stability, regulates the microbiome, and counteracts inflammation. A stable, acidic pH is crucial for maintaining the integrity of the skin barrier. Fluctuations in pH can not only impair the skin’s barrier function but also exacerbate dermatological conditions.
SKIN pH LEVELS IN DIFFERENT PARTS OF THE BODY
Did you know that the skin’s pH level can vary depending on the area of the body? For example, the pH level on the face is often lower than on the arms or feet, since the face is more exposed to environmental factors such as UV radiation or dirt particles, and the skin there is more sensitive. The skin’s pH level on the body can be influenced by various factors, such as clothing, sweat, or skincare products.
CHANGES IN pH LEVEL WITH AGE
As we age, not only does the condition of the skin change, but so does its pH level. Studies show that the skin’s pH level tends to rise over time and is often higher—that is, less acidic—in older adults. This is because the skin becomes drier with age and produces less sebum, which can lead to a disrupted hydrolipid barrier. An elevated pH level can weaken the skin barrier, leading to dryness, irritation, and an increased risk of skin conditions. The use of pH-neutral products and moisturizing skincare products is therefore particularly recommended as we age to support the skin’s natural acid mantle.
CLEANSING AND ITS EFFECT ON THE SKIN’S pH LEVEL
Gentle cleansing is highly recommended to preserve the skin’s natural pH level. Even simple contact with water can disrupt the skin’s acid mantle, as tap water is usually slightly alkaline. Additionally, harsh surfactants or alkaline cleansing products can disrupt the skin’s pH level and make it more prone to irritation. The Ten out of Ten Gentle Gel Cleanser by DR EMI ARPA SKIN, with a skin-neutral pH of approximately 4.9, offers gentle cleansing that supports skin health and preserves the natural balance of the skin’s acid mantle—and thus its barrier function.
