Hair pH, what it is and why it is important
We often hear in cosmetics and the haircare world talk about pH. Sayings like “acid ph” or “basic ph” or “skin-friendly ph”. Ph has really entered common parlance. But what does it really mean? Let’s look at it together!
What is pH?
Skin pH depends on the water-soluble substances contained in the stratum corneum, the components of the hydrolipid film, and the amount of carbon dioxide emitted. The optimal or physiological value varies depending on the skin area as well as gender: on average in women it is 5.5, while in men it is about 5. The pH level ensures the proper chemical environment for the skin to maintain its bactericidal barrier.
Its measurement detects the amount of hydrogen ions present in a water-based compound.
The pH scale is used to measure the relative acidity or basicity of a substance: it ranges from 0 to 14, where 7 represents neutrality. Above this threshold a substance is alkaline (basic), below it is acidic.
How does pH affect the hair?
The pH of the scalp is around 4.5 and 5.5, while on the hair it is more acidic, it can be as low as 3.5, in fact the hair is coated by a hydrolipidic film.
In formulations it is therefore necessary to obtain a pH from the correct value to respect the physiological balance of the area to be treated.
The use of products with an unsuitable pH can in fact cause damage to the hair.
In general, products with a high pH (basic) open the cuticles favoring the entry of nutritive products: it is very important after using basic products, to restore the pH of our hair making it return to a normal level between 4 and 5.5. Conversely, using substances with a low pH acts on our hair by closing the cuticles, sealing the cortex and retaining moisture.
What is the pH of hair products?
To continue to have healthy hair, it is recommended to use products with a pH range between 4 and 5.5. Almost all shampoos and conditioners are calibrated to maintain the acidic state of our hair and scalp. Shampoos generally have a pH range of 4 to 6, while conditioners have a lower pH (3.5-5).
What is the purpose of using a pH-balanced shampoo?
A pH balanced shampoo helps clean the hair of dirt and product residue. The washing power of the shampoo also tends to take away some of the hydrolipidic film, so to balance it is always recommended to use a conditioner to restore nourishment and hydration. Conditioners also helps to close the cuticles, making the hair healthier and less vulnerable to external agents.