Why pH 5.5

Skin's natural protective acid mantle

Changes in the pH value of the skin weaken the protective function of the acid mantle.
This promotes skin infection, dehydration, skin irritations and allergies.

The skin's natural defense system

The pH value shows whether a liquid is acidic, neutral or a base (alkaline). The pH scale ranges from 0 to 14. The neutral point is 7. Values over this point denote bases, values under this point acids. The further the value is away from 7, the stronger is the acid or base
The skin's natural protective acid mantle

Not only skin contact with strong acids or bases but also daily skin care can damage the protective acid mantle when soap or other care products whose pH value does not correspond to the skin's natural pH value of 5.5 are used. This is true for most so-called preparations with skin neutral pH.