Did you know that the skin in different regions of the body has different pH? Because? What is the importance of cleaning the intimate region with products with an adequate pH? What is pH? Did you know that inside our hair there are different pH's? Did you know that the baby is born with alkaline skin and then becomes acidic?



What is pH?


In chemistry, pH is a dimensionless numerical scale used to specify the acidity or basicity of an aqueous solution , a substance, food, and even skin.


It is used to measure the degree of acidity or alkalinity (basicity).



Pure water is neutral, as it has a pH of 7 at 25°. Solutions with pH values less than 7 are acidic and solutions with values greater than 7 are basic .


On the labels of some products it says “regulates skin pH” or “even skin pH”? It is quite common to read this on the packaging of creams and lotions. But do you know what it means and why it is important for your beauty?


We must use products that are compatible with our pH, products with a pH close to or equal to that of our skin. Because, using products with a very different pH, our skin will be sensitive, irritated.

In the skin, the pH is defined by the mixture of water, acids, mineral salts, fat and other elements expelled by the sebaceous and sweat glands.



Is the skin's pH not neutral?

The natural pH of healthy adult skin is slightly acidic, between 4.5 and 5.75. This pH range is called: “physiological pH”. However, the pH varies throughout the day .



How important is pH for our skin?


The pH of our skin is between 4.7 and 5.75, that is, it is slightly acidic. Because? It is slightly acidic so that microorganisms do not develop on our skin. The pH forms an acid mantle, which acts as a barrier to the multiplication of viruses and bacteria that live on our skin.


Escala de PH da pele



Is it normal to have microorganisms on our skin?

Yes, to some extent.

In fact, there are microorganisms (good and bad) on our skin constantly, and some fight other microorganisms that are more harmful to us.

Let's call some good microorganisms and others bad microorganisms. These bad microorganisms fight other bad microorganisms, more harmful than them.

In other words, it is advantageous for our skin to harbor both good and bad microorganisms, in small amounts. However, these microorganisms are only beneficial on the surface of the skin and should not enter the body, for example, through a wound. Inside the body they could be harmful.

What are the consequences of changing skin pH?

If the pH rises to alkaline or drops to too acidic, the skin's natural balance is compromised:

  • various substances are no longer synthesized,
  • water loss increases
  • and the epidermis (outer layer of the skin) cannot function as a bioprotective shield .

 In this way, the cosmetics we use must have formulas that respect the physiological pH. They must maintain the acidity that inhibits the proliferation of harmful microorganisms that damage the skin barrier, causing irritation, inflammation or infections.

What are the symptoms of an unbalanced pH?

When we use products with a different pH than our skin, we alter our skin barrier and impair its protection.

The skin suffers and the symptoms of an unbalanced pH manifest themselves as follows:

  • dryness,
  • redness,
  • feeling of discomfort
  • some other unusual change.

Does pH change over life?

Right after birth, the pH of a newborn's skin is alkaline, given by the presence of vernix caseosa, (a fatty and whitish substance that covers the baby at birth). Over the 24 hours following parturition, the pH drops to acidic.



This variation ensures the pH necessary for the body to protect itself. When we are born, our immune system is not fully developed. In this way, if the skin is alkaline, it inhibits harmful external agents.


During the first month of life, as the immune system becomes stronger, having more protection tools, the pH stabilizes at 5.5, the physiological pH at which the skin remains during adulthood.

Likewise, baby hygiene products differ from adult products, as the baby's skin baby is still not exactly like adult skin.



Is the pH the same throughout the body?

Have you ever noticed that your skin is not the same on all parts of your body? It is thinner in the eyes, so the eyelids move quickly to lubricate the eyeball. On the soles of the feet, the skin is thicker, helping to cushion the impact when walking, running, jumping…

The skin differs in different parts of our body, the pH too!



In regions close to the genitals , the pH is lower : around 4.2. This more acidic environment is intended to inhibit microbial infestation in these areas that are constantly covered and damp. That's why intimate soaps are different from soaps for the rest of the body.



What is the pH of dry skin and what is the pH of oily skin?

For each pH, the skin will show some characteristics.


Dry skin — acidic pH

Dry skin has a pH of less than 6.5, possibly closer to 4. Therefore, it is extremely acidic and needs a nutrition supplement. The skin is more sensitive, thin and opaque. It is more likely to flake off easily.


Normal skin - 4.4 to 5.75

It is smooth, soft and with barely visible pores.


Oily skin – basic pH

Oily skin has a pH level that exceeds 6.5. It is alkaline skin that needs more acid. Intense shine, dilated pores and more incidence of blackheads and pimples.



What factors change the skin's pH?
There are many external and internal factors that can change the skin's pH.

  • temperature changes
  • humidity changes,
  • tobacco,
  • stress,
  • alcohol,
  • cleaning,
  • pollution,
  • alkaline cosmetics,
  • Chemicals.

The latter are quite harmful, as they overload the skin's natural neutralization capacity, causing damage to its structure. The protective mantle of the hands is constantly threatened, for example, with detergents.

O que é o pH da pele e por que ele é importante?


The armpit area , when long periods without contact with light or air, can create conditions that help bacteria to grow. In addition, chemicals in some antiperspirants and/or hair removal products also contribute to lowering the pH.

These factors damage the hydrolipidic layer of the skin, leaving it dry, sensitive and subject to blemishes or irritation. To keep the skin barrier intact, we must use products with a pH value lower than 7. In addition to equalizing the level of healthy skin, they neutralize bacteria that can activate the skin's immune response, producing a lot of sebum.

How to measure skin pH? How to find out the skin's pH level?

If you want to measure the pH levels of a product, pharmacies sell color-coded pH test strips. If the marked color is close to red, it means that your product is acidic and not alkaline.

So when you say a cream is neutral what does it mean?

It means that its formula is basic and has no products that can react with others that you want to add to the cream and that the cream can be used on all skin types.


In a neutral massage cream, for example, essences can be added to potentially achieve a desired effect.
Thus, a neutral cream does not mean that it has a pH=7.





Catarina Vilela - Nurse