The “low pH” is just a marketing gimmick or something worth paying attention?


Nowadays, there are numberless skincare products saying they are “low pH”. Is it a just marketing gimmick or something that we should sit down and take a look? If it is worth paying attention, what does it exactly mean and how does it affect my precious skin? Let’s figure it out.

To give you a concrete foundation to decode the “low pH”, I want to tell you some sort of a scientific definition first. So don’t be panic. The pH (Potential of hydrogen ion) is related to the concentration of hydrogen ions. Higher concentrations are more acidic (like lemon), whereas lower concentrations are more alkaline (like detergent). The pH scale ranges from 1 to 14, with 7 at the center denoting neutral pH-neither acidic nor alkaline. A pH lower than 7 is acidic, in vice versa, it is alkaline. The ph within the body range from 7.35 to 7.45, thus the body’s normal pH is close to neutral.

However, the skin pH is different. Skin can be divided into the dermis (inner layer) and epidermis (outer layer). Normally the molecular size of skincare products is too large to penetrate epidermis and reach dermis, so we better focus on the pH related to epidermis. The epidermis is basically acidic. The ph of the top epidermis layer, the stratum corneum, drops to between 4.5 and 5.5. This is the normal pH range of the skin surface. If you use the skincare product with the pH level of 7, the epidermis pH would increase to between 6 and 7. Then, the skin produces less enzymes that create Ceramide, Cholesterol, and Fatty acids which are all the key ingredients to make up lipids (natural adhesive making the skin barrier concrete). Consequently, the skin barrier gets weaker.

More specifically, in the case of atopic dermatitis or high pH level situation, various skin barrier components are insufficiently synthesized and the epidermis is damaged. As a result, skin inflammation continues to worsen because the skin is exposed to more pro-inflammatory substances and numbers inflammation-related signaling chains are activated. Next, the high pH damages the protein component called “Filaggrin” to hold water in epidermis leading to moisture loss on skin surface. Moreover, Filaggrin is related to maintain the optimal pH level for skin surface. So if it gets damaged, the skin pH level even wound increase higher.

When it comes to cleanser, the cleansing effect is much better when the pH level of the product is higher. For example, laundry soap is strongly alkaline, and it has great cleansing effect with a pH level of about 11. But people avoid using it on the skin. Laundry soap removes not only waste, but also all normal lipids from the skin. When soap of ph 11 is used, the skin pH level soars like a rocket. A rise in ph leads to an environment in which lipids cannot be created actively and weak skin conditions would persist. Then various external factors can cause inflammatory reactions and other problems as the skin barrier becomes progressively weaker.

These days, people often use the low pH cleansers which helps make the skin healthy. However, the cleansers with a pH of 4.5~5.5 have a relatively weak cleansing effect. When the cleanser only focuses on pH rather on cleansing effect, it just works to avoid skin irritation. Such cleansers often cannot cleanse the skin properly, and they may not remove skin waste, even after several washes. This is why many low pH cleansers have a ph higher than 4.5-5.5 but slightly lower than ph 7.

In conclusion, to normalize the skin with high pH level, it is essential to use low pH (sub-acidic) products. Even though you finish cleansing well enough, your skin still could be dry ,dull, burning feel and irritated due to the wrong pH level of your skin.

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