Der pH-Wert: Sauer, basisch oder doch neutral?

The pH value: acidic, basic or neutral?

Part I: Why our skin loves a little acid


by Dr. Huong Nguyen | Editor: Dr. Sabine Nunius | April 28, 2022

“pH neutral” - you've probably come across this term many times when it comes to skin care products. Creams and washing lotions in particular often advertise that they fulfill this property. If you've asked yourself the question: What's that all about? And are pH-neutral products really best for my skin? Perfect! Then this is exactly your story today!

I'm going to digress a bit and start today with a little excursion, this time into the world of chemistry.

pH value or “acidic vs. basic”

So first: What exactly does the pH value actually mean? Basically, the pH value gives us information about whether an aqueous solution is more acidic or more basic. Why are the letters p and H used for this? These stand for potential of hydrogen, Latin pondus hydrogenii or potentia hydrogenii. Water, more precisely pure water, also underlies the definition of “pH neutral”. However, neutrality is not set at a pH value of 0, but at 7. pH neutral therefore means pH value = 7. Completely logical? Not quite, but you get used to it :-) Derived from this, all solutions that are below a pH value of 7 are acidic, all above are basic or alkaline.

Still too abstract? Here is a small list of examples:

Sour keeps safe - the function of our acid mantle

Now back to my original question: Which pH value is best for caring for your skin? Your skin itself provides you with the answer, or more precisely its structure. We don't even have to go into depth about this. Directly on the surface you will find the hydrolipid film, a thin layer of sweat, sebum and water. This film has a pH of 4.5 to 5.5. The exact value varies from person to person and is not the same in all parts of the body - but in every case it is a slightly acidic environment. This also explains the name “acid” protective coat.


We've done the chemical part. In part 2 of this story we will take a closer look at the function of the acid mantle and the ideal pH value in skin care products.