Skin pH: why it matters for your skincare routine

We often hear about products that are “pH-balanced for the skin,” but what does that really mean? The skin’s pH is one of the quiet but essential pillars of healthy skin. Understanding it helps you make more informed skincare choices, starting with your cleanser.

Healthy skin is naturally slightly acidic, and maintaining this pH level is essential for the skin’s barrier to function properly: respecting this pH level—especially when cleansing—is one of the keys to a successful skincare routine. Here's why.

What is the skin's pH?

pH is a scale that measures acidity or alkalinity, ranging from 0 (very acidic) to 14 (very alkaline), with 7 being neutral. The surface of healthy skin is not neutral: it is slightly acidic, with a pH generally ranging from 4.5 to 5.5. This surface acidity forms what is known as the “acid mantle,” a protective film composed of sebum, sweat, and skin byproducts.

This acid mantle is not just a minor detail: it plays a central role in protecting the skin and ensuring the proper functioning of its barrier.

Why is this acidic pH so important?

The skin’s slightly acidic pH serves several essential functions. First, it supports the activity of enzymes that organize the lipids in the skin barrier: a proper pH is necessary for a strong, impermeable barrier. Second, it helps maintain the balance of the skin microbiome, promoting beneficial bacteria while limiting the proliferation of unwanted germs, which thrive in more alkaline environments.

Scientific literature confirms this: an increase in skin pH is associated with impaired barrier function and more vulnerable skin. Maintaining this acidic pH is therefore essential for comfortable, resilient, and balanced skin.

What Disrupts the Skin's pH

Several factors can cause the skin’s pH to shift toward alkalinity, thereby throwing it out of balance. The main factor is the use of cleansers that are too harsh: conventional soaps, which are often highly alkaline, can cause long-term disruption to the skin’s acid mantle. Other factors include hard water, certain environmental factors, and—as we age—a natural tendency for the pH to rise.

An imbalanced pH often results in tight-feeling skin after cleansing, redness, increased sensitivity, or discomfort—all signs that the skin barrier has been compromised.

Cleaning: A Key Step in Maintaining the pH

It is during cleansing that maintaining the proper pH level is most critical. Research on cleansers shows that formulas that are too alkaline can damage the skin’s proteins and lipids, while cleansers with a pH close to that of the skin are better tolerated. It is therefore best to choose gentle, soap-free cleansers that cleanse without stripping or disrupting the skin’s balance.

It was with this in mind that the PERS Soothing Cleansing Gel was developed: soap-free, it gently cleanses while maintaining the skin’s natural balance, making it suitable for both sensitive and oily skin. When used with the PERS Radiance Makeup Remover Balm as part of a double-cleansing routine, it effectively purifies the skin without compromising its acid mantle.

Should we be concerned about the pH of each product?

Not necessarily. While pH is most important in cleansers, other skincare products are generally formulated with pH levels suited to their function and designed for good skin tolerance. The most important thing is to remember the principle: preserve the skin’s acid mantle—especially by avoiding harsh cleansers—rather than measuring the pH of every bottle. Skin whose pH is maintained is better equipped to stay comfortable and resilient.

Key Takeaways

Healthy skin is naturally slightly acidic (pH around 4.5 to 5.5), and this acidic mantle is essential for the proper functioning of the skin’s barrier and the balance of its microbiome. Cleansers that are too alkaline are the main cause of imbalance, which is why it’s important to choose gentle, pH-balanced cleansers. By paying attention to this often-overlooked factor, you provide your skin with the conditions it needs for lasting comfort and resilience.

Scientific Sources