What evidence convinces you that products need to be pH balanced?

PerryPerry Administrator, Professional Chemist
edited July 10 in Science
This is a good read about pH and the science (or lack thereof) used to support claims made about it.


What does pH balanced mean to you?  And why do you think it matters?

Certainly, it matters in terms of the effectiveness of a preservative system or a hair chemical treatment, but for shampoos and skin lotions, there's not much scientific evidence - at least that I know.  How about you?


  • PharmaPharma Member, Pharmacist
    Having an intact "acid mantle" i.e. slightly acidic pH on the skin helps reducing microbial growth. Absence of an acid mantle is allegedly (I say allegedly because I haven't read anything useful since I can't read everything) linked to increased (infection related) skin disorders.
    On the other hand, we're in the era of probiotics and talk also about skin microbial flora... as it seems, an intact microbial flora (not just on the skin, but everywhere where we have microbes) is a more effective protection from "bad" microbes. A lower pH allows for the growth of lactobacilli and these are often the "good" guys -> a low pH would go well together with the skin microbiome hypothesis.

    BTW "balanced pH" is a stupid marketing term and means nothing.
  • JonahRayJonahRay Member
    edited July 11
    I've read a lot about this but more in terms of skin cleansing. What I read was that after cleansing with bar soap for instance it requires quite a long time to return to optimal pH which leaves the skin in a more compromised state for longer. My reason for researching this was to see if using a more acidic toner is an effective way of rebalancing the skins pH allowing for quicker recoup after cleansing.

    My thoughts when choosing a pH is that it really needs to be one that is compatible with the ingredients, especially the preservative system. We use exfoliating acids on our skin which certainly are not at skin pH so why should it matter. 

    My understanding is the skin is very capable of re-acidifying after applying a cream that may be more basic for instance.
    Cosmetic Product Development
    Sussex Research Laboratories Inc.
  • GuntherGunther Member
    Does 'balanced pH' have any exact definition?

    "Optimized pH" works great in my opinion:
    Slightly acidic pH (5-6) for skin mildness
    a bit more acidic (4-5) for smooth hair
    and about neutral pH to reduce eye irritation.
  • Great article, have done similar research myself. One interesting point though, and this is really old science (that's because Im a really old guy).... soap, body wash etc is designed to clean, and cleaning chemistry occurs better in a more acid than neutral or basic environment.
    Dr. Mike Thair
    Cofounder & Chief Formulator
    Indochine Natural
  • PharmaPharma Member, Pharmacist
    @Perry: Just stumbled upon the book "Handbook of Cosmetic Science and Technology" by Barel, Paye and Maibach.
    Chapter 20 and 21 are about skin pH.
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