Soaps and Skin pH: how to choose the right one

What pH values should cleansers have in order not to disrupt the skin’s balance?

When choosing the right soap for your skin, it is essential to consider several factors, such as the formulation of the products and their cleansing power, but one of the most important aspects is pH. The skin naturally has a slightly acidic environment that contributes to maintaining the skin barrier and microbiotic balance. Understanding the relationship between soap and skin pH helps us respect and protect this environment and, consequently, choose the most suitable products for daily cleansing.

What is the pH of the skin?

pH is a value that indicates the hydrogen potential of a solution, i.e. its concentration of hydrogen ions, and is measured on a scale ranging from a minimum of 0 to a maximum of 14. pH therefore provides information about the acidity or alkalinity of a solution, which is considered neutral at the midpoint (pH 7).

The skin’s surface usually has a pH between 4.5 and 5.5, although this value can vary depending on several factors, including the area of the body, age, individual characteristics and skin conditions. Skin pH is therefore considered slightly acidic, as it is below 7 (while values above neutral pH are considered alkaline).

This environment is often referred to as the acid mantle and plays an important role in maintaining the skin’s barrier function. Using overly aggressive soaps or frequently applying highly alkaline products can temporarily alter the skin’s surface pH and cause dryness or irritation, especially in people with sensitive skin.

What is the pH of soaps?

Traditional soaps are generally alkaline products, with a pH above 7. On average, soap pH ranges between 8 and 10, as the saponification process requires an alkaline environment. There are also exceptions: intimate cleansers, for example, have a deliberately low pH (between 3.5 and 5.5), while some liquid cleansers have a pH of 5.5 and are often referred to as “soap-free” or “non-soap” cleansers.

However, the fact that common soaps have a higher pH than the skin’s physiological pH does not mean that they are harmful. In fact, when we wash, the skin’s pH is temporarily altered, but our body tends to restore its natural levels within a short time.

What pH should a skin cleanser have?

In general, we can say that there is no single ideal pH value that applies to all products and all people. For daily cleansing, it is advisable to choose soaps with a slightly acidic pH or one as close as possible to that of the skin, while also paying attention to the formulation, frequency of use, surfactants present and each person’s individual characteristics. For dry or sensitive skin, it is preferable to choose products specifically formulated to respect the skin’s natural balance.

A general guideline for choosing soap pH according to skin type could be as follows:

• for dry skin: use soaps with a slightly acidic pH that are gentle, emollient and moisturizing;
• for sensitive skin: choose soaps with a pH similar to the skin’s natural pH (around 5 or 5.5);
• for normal or combination skin: soaps with a pH between 5.5 and 7.5 are suitable. Neutral soaps (i.e. those with a neutral pH of 7) are the most widely available;
• for oily skin: avoid overly aggressive cleansers and those with a high pH, and instead choos soaps with a pH between 4.5 and 5.5, which are sufficiently acidic to help counter bacterial proliferation.

Find out more about which soap to use for your skin type

Alchimia Soap natural soaps are cleansers designed to respect the skin’s pH, thanks to carefully researched formulations, the use of selected high-quality ingredients and artisanal production backed by the guarantee of Made in Italy.

Choose your favorite products and fragrances for your daily beauty routine from the many options available in our cosmetic lines, and buy soaps online to have them conveniently delivered to your home: visit our shop now.