In summary, shampoos with a pH of 5 to 6 open the cuticle for cleansing, while conditioners with a pH of 4 to 5 close it to retain moisture.

The Acid Mantle & Optimal pH Balance

The skin protects itself using a thin, protective layer known as the acid mantle. The acid mantle of the skin is formed by secretions from sweat glands and sebaceous glands. Sweat contributes amino acids and lactic acid, while sebaceous glands produce sebum, which consists of fatty acids or “natural oils”.

If our skin falls out of this range due to hydration levels, environmental factors, or topical products, our acid mantle can weaken and leave us more vulnerable to a number of skin and scalp issues like fungal growth and bacteria.

The optimal pH balance of the acid mantle typically ranges from 4.5 to 5.5 pH. The aim of 'pH balancing' is to use products that maintain hair and skin near their natural pH levels, keeping both your skin and hair moisturized and healthy.

Minerals In Water

The pH of water significantly affects mineral absorption in hair, with higher pH levels resulting in greater mineral binding/buildup. Minerals in water can stiffen hair, decreasing elasticity and flexibility, which leads to increased friction.  This friction heightens hair porosity as hairs rub against one another, potentially breaking cuticles and causing tangles.

Hard water is characterized by high levels of calcium and magnesium (but not limited to others), with a pH of about 8 or higher, making it alkaline.

Soft water has lower concentrations of these minerals and higher levels of sodium, resulting in a slightly acidic nature with a pH around 6.5.

It has been found that the neutral pH 7 of water, both bleached and unbleached hair absorbs fewer minerals compared to water at a pH level of 8 and 9.   Although damaged hair absorbs more minerals overall, pH levels play an important role in this process.

Tip: To assess your water quality, add dish soap to an empty plastic bottle, followed by tap water, and shake.  Minimal bubbles indicate high mineral content, while more bubbles suggest lower mineral levels.  Testing kits are also available for purchase online.

Options & Solutions

Keep in mind the following options are guidelines and may take a little trial and error as hair pH is not affected immediately; rather, it requires time to stabilize and return to its normal state after exposure to different products or chemical treatments over the years.  Other factors come into play, such as the environment, genetics and your hair type.

Consider investing in a filter for your shower if you have hard water or rinse with distilled water.  Additionally, use the correct pH level products for hair then include one of the options below that best suits you.

1) Use a slightly acidic final rinse, such as diluted apple cider or rice vinegar, to restore and maintain the desired acidic pH after washing hair.   Add 1 part apple vinegar to 3 to 4 parts of water in a spray bottle.  This practice is particularly beneficial for individuals with hard water, which is alkaline and can disrupt the hair's pH balance.  Aloe juice is a good option too.

2) Partially rinse your conditioner off. Over time, you can determine how much or less rinsing is needed.  This will not work well with products containing silicones due to build-up over time.  JoPaulo conditioners work well left on the hair, partially rinsed, or rinsed off.

3) Use leave-in conditioners.   This is best for chemically lightened or bleached hair. This may work with damaged or overly dry hair too. For certain hair types, this may not work long-term.   Avoid any silcones.

4) Coat the hair slightly (do not over saturate) with a good quality oil with no fillers or added ingredients.   Apply this oil (a bit at a time) to the mid-ends and ends of your hair while it is still dry, and before stepping into the shower.   Shampoo and condition as normal.