pH value

The pH of our skin is between 4.5 and 6.0, which means that our skin is slightly acidic.

The slightly acidic pH is important for keeping the skin – and everything that lives on it – in a healthy balance.

Interesting facts about pH

What factors influence pH?

The skin’s own various sources of acidic substances and buffer substances (sweat, sebum, metabolic processes in the horny layer and microorganisms on and in the skin) determine the pH from within. They in turn are subject to internal influences, e.g. hormones, illnesses, gender and age. Inflamed skin or open wounds also have a pH above 5.5. This is compounded by many external influences such as diet, medication, climate, social contacts, professional activity, lifestyle habits and, last but not least, skin cleansing and care. The use of soap or products with a neutral or alkaline pH for skin cleansing can lead to an increase in the skin’s pH. Skin care products with a pH above 6 can cause the skin to be less acidic than necessary for its health.

Why do different areas of the body have different pH values?

The face, scalp, hands, feet, arms, legs, back, chest, stomach, armpits and intimate areas differ in terms of skin structure, hairiness, density of sebaceous and sweat glands and colonisation with microorganisms. As the skin’s pH is influenced by these factors, it varies depending on the location. A pH above the normal average value of 5.5 is found in particular in the areas between the fingers and toes, the armpits and in the genital area, but also in skin folds (under the breasts in women, between the buttocks and folds due to excess fat).

Measuring pH

Although our sense of taste allows us to perceive pH values (acidic, neutral or bitter taste), this method is not suitable for corrosive acids and alkalis or even toxic substances. Various dyes make pH changes visible. These indicator substances are used for quick estimates of pH. An electrochemical measurement with a pH meter, which is also used to determine the pH on the surface of the skin with special adaptations, is more accurate. Fluorescent dyes and modern imaging methods (fluorescence lifetime imaging – FLIM) can visualise different pH values microscopically in the individual skin layers.

pH FAQ

What does the abbreviation “pH” mean?

pH is the abbreviation for the Latin potentia hydrogenii, which translates as hydrogen ion concentration. Anything that contains water, including our bodily fluids, has a pH between 0 and 14. pH 0 denotes a maximally concentrated acid, while pH 14 is a maximally concentrated alkali. A pH of 7 is in the middle of this scale and corresponds to that of neutral water. pH can be determined using electrical measuring devices or indicators such as litmus paper.
Is our skin equally acidic everywhere?

Not quite. Although it is slightly acidic everywhere from head to toe, it is a little more acidic in the armpits, in the genital area and between toes and fingers. In addition, only the uppermost horny layer of the skin and the hydrolipidic film covering it are generally acidic. The deeper layers of skin underneath, on the other hand, are pH-neutral.
Why is the skin acidic?

Because it is healthier: The slightly acidic pH keeps the barrier structures in the horny layer stable and supports their regeneration. It also maintains the ecological balance of the skin microbiome, i.e. the totality of all microorganisms living on the skin.
What is the effect of the pH 5.5 of sebamed?

The pH 5.5 of sebamed is adapted to the skin’s natural protective layer. This means that sebamed products can ideally support healthy skin functions. This optimises product compatibility and the care effect even for sensitive skin.

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