Importance of a low pH cleanser


Educating customers about their product with scientific information is a growing trend within the cosmetic market. Customers demand for products that deliver both immediate and long-term results, and what best way for brands to gain a customer’s trust by proving to them that they will see results by scientific evidence. This not only helps to build trust and loyalty to a brand, but also assists customers in building deeper understanding with their own skin. Take the COSRX low pH Good Morning Gel Cleanser (£8.90), the title of the cleanser already touches upon scientific information about the cleanser’s pH.

This type of marketing however, requires prior knowledge or an informed explanation on their website or on the product for those who are not already aware of the benefits that a low pH cleanser has. Nowadays, customers feel reassured when well-known influencers and bloggers test and recommend products to them, but a lot of the time, their trust is placed in sensorial evaluation, meaning, the appearance, texture, touch, odour the user can pick up on, This level of information is more surface level, and both brands and customers could really benefit from educating themselves with the science behind it all.

What is pH?

pH essentially is a measure of the concentration of hydrogen ions in a solution. Proteins are essential for healthy maintenance of the skin and they rely on hydrogen bonds to maintain their shape. The pH of the body must be maintained at a stable level to ensure that proteins in the skin keep their shape to function.

It is ideal that a cleanser has a slightly acidic pH close to the pH of the skin (4.0-5.0) to maintain its pH (Fluhr and Elias, 2002). Our skin contains a thin film known as the acid mantle which acts as a barrier to bacteria, viruses and other contaminants that may penetrate the skin (Ali and Yosipovitch, 2013). Recent studies demonstrate that solutions with high alkali pH (approximately pH 10), even in the absence of surfactants (compounds in a cleansing formulation that removes dirt from the skin) can increase the swelling of the outer most layer of the skin – stratum corneum and alter lipid rigidity (Global and Innovation, 2004). Thus, suggesting that cleansers with neutral/acidic pH, close to the stratum corneum, may cause less potential danger to the skin, as it will not alter our skin’s natural acid mantle.


Ali, S. M. and Yosipovitch, G. (2013) ‘Skin pH : From Basic Science to Basic Skin Care’, Acta Derm Venereol, 93, pp. 261–267. doi: 10.2340/00015555-1531.

Fluhr, J. W. and Elias, P. M. (2002) ‘Stratum corneum pH : Formation and Function of the “ Acid Mantle ”’, 94121(190), pp. 163–175. doi: 10.1159/000066140.

Global, U. and Innovation, S. (2004) ‘Cleansing without compromise : the impact of cleansers on the skin barrier and the technology of mild cleansing’, 17(8), pp. 16–25. doi: