Acidic and Alkaline pH Levels & Why They Matter for Healthy Hair

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Acidic and Alkaline pH Levels & Why They Matter for Healthy Hair

I first published this post when my hair was relaxed back in 2014. Back then, rinsing my scalp with ACV at the end of my wash worked so well for my relaxed hair and scalp (helping to calm itchy scalp and flakes for weeks) that made me 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.


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.
  • If you relax 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 wonder where some of my staple products now fall on the pH scale. It’s time to order pH strips again and test everything!

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