Acidic and Alkaline pH Levels & Why They Matter

Rinsing my scalp with ACV at the end of my wash has been working so well for my scalp (I haven’t had an itchy scalp or flakes in weeks) that it’s made very curious about the benefits that my hair and scalp would reap if I focused on making sure my hair and scalp were pH balanced on a consistent basis.

Let’s tackles what pH is first. The EPA provides the following:

The pH scale measures how acidic or basic a substance is. It ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is basic. Each whole pH value below 7 is ten times more acidic than the next higher value. For example, a pH of 4 is ten times more acidic than a pH of 5 and 100 times (10 times 10) more acidic than a pH of 6. The same holds true for pH values above 7, each of which is ten times more alkaline—another way to say basic—than the next lower whole value. For example, a pH of 10 is ten times more alkaline than a pH of 9. Source

Why does the pH level of products matter? Our hair and sebum have a natural pH level between 4.5 and 5.5. The products we use have the potential to throw off our natural pH levels.

Acidic substances:

Acidic products close the cuticle layer of the hair. For high porosity ladies, using an acidic product after deep conditioning will help close the cuticles along the hair shaft, thereby sealing moisture into the hair. For low porosity ladies, whose hair cuticles are already tightly sealed, using a product with a low pH will further compact the cuticles, making it harder for moisture to penetrate into the hair shaft.

Alkaline substances:

Alkaline products range between 7.1 and 14. These products cause the hair cuticle to swell in order to penetrate into the hair shaft. Relaxers and hair dyes are two well-known hair alkaline products. Relaxers have a pH level between 9-14 (lye, 12-14; no-lye, 9-11). Temporary hair dyes have a pH level between 7 and 8. Semi-permanent hair dyes have a pH level between 8 and 9. Permanent hair dyes hair a pH level between 9 and 11.

Benefits of balancing the pH level of your hair and scalp:

  • A properly pH balanced scalp is a happy scalp (reduction flakes and itchiness).
  • pH balanced hair (hair that is maintained within its natural 4.5-5.5 range) retains moisture more efficiently.
  • After relaxing your hair, it’s absolutely necessary to use a neutralizing shampoo to stop the relaxer from processing your hair (over-processing your hair opens to door for damage, breakage, thinning, limp and lifeless hair).

How to balance your hair and scalp’s pH level:

  • Use products that have a pH level between 4 and 7. It’s uncommon for products to list the pH level on the packaging but purchasing pH strips and a simple way to determine the pH level of your product. If you’re scanning the ingredient list and spot citric acid, sodium hydroxide, or triethanolamine, they are added in small amounts to products to slightly lower the products pH level.
  • Use an apple cider vinegar rinse. Apple cider vinegar has a pH level of around 3 so it must be diluted with water. The common ratio I see is 2:1, but as will all things, what works for one, may not work for another so take care to really figure out what works best for your hair and its needs.
  • Do a quick pre-poo with aloe vera juice, which has a pH between 4.5 and 5.5 (and is also a nice detangler) to help return your hair to its natural pH level.

I plan on purchasing pH strips within the next week or so to test out the pH levels of products I use regularly and the ACV mix I used weekly. I’m looking forward to see where my staples fall on the pH scale.

13 Comments


  1. Sodium hydroxide (lye) is a strong base. It would actually raise the pH of products.

  2. Thanks for posting this. I've been pH testing some of my products and mixes, and I was amazed of how off they were. Before reading up on pH for hair, I used the French Perm Stablizer Plus after a relaxer and my hair was so matted and tangled. I knew this was the culprit, because that was the only new thing I tried. My hair felt like it was glued together. I wanted to cry that day. It took so long to detangle my hair without ripping my strands apart. The pH for this is 2.5 which is too acidic for my hair.

  3. Please do share where you find the PH strips…….
    I've been trying the ACV rinse and it's been effective for itches but not good for retaining Moisture since i'm Low Po..Natural Aloe Vera itches my scalp but works for my hair…..Thanks to all the hair bloggers, i can manage how i use both products to get effective results.
    The Beautiful Eagle's Blog

      1. Can you provide the URL link to the post on Amazon?

    1. Author

      That sounds like a really interesting mix!

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