With their pH value of 5.5, sebamed products are optimally adjusted to the slightly acidic acid mantle of the skin surface. Bacteria which can potentially cause skin disorders, such as Staphylococcus aureus, are prevented from spreading by the acidic milieu. By contrast, the majority to the microbial population of the skin, which is innocuous or even beneficial, is well adapted to this milieu and able to keep the more dangerous species in check. This happens on the one hand by displacement, but also by excretion of inhibitors and by activating the defense mechanisms of the skins own immune system.
Skin cleansing products with neutral or alkaline pH values alter the acidic environment. This can disturb the healthy microbial balance. As early as the 1990s, a study on bacteria which, although harmless, are responsible for the widespread and stressful skin disease acne, showed that washing daily with alkaline soap for 4 weeks leads to an increase in the skin surface pH value. Although this is slight, it causes an increase in acne bacteria, which can be reversed by switching to a soap-free skin cleansing product with a pH value of 5.5. In this case, a 4-week application of the acidic soap-free skin cleansing product reduces the number of acne bacteria whilst the change to alkali soap leads to an increase. A further study proved the relevance of these findings: while using soap leads to more pimples, washing with the sebamed soap-free cleansing bar decreases their number significantly.
Creams and lotions contain water and therefore also have a pH value that can affect the skin's pH. As such care products, unlike skin cleansing products, are not rinsed off immediately; their influence on the pH of the skin surface can last for several hours, as studies have shown. If the skin is stressed, this affects its barrier function and consequently also the microbial balance. Skin care products with a pH value of 5.5 can more effectively protect than those with a higher pH value against damage to the barrier function and they are able to accelerate its regeneration after damage. This reduces the risk of a disturbance of the microbial balance. It has been shown that regular skin care with pH 5.5 over several weeks does not cause any changes in the healthy skin microbiome.
Skin cleansing and care, which stabilizes the slightly acidic skin surface pH value, helps to maintain a healthy skin microbiome.