What is the sebum film?

In fact, there is a thin film on the surface of our skin, also known as the natural sebum film, which is mainly formed by a combination of lipids secreted from the sebaceous glands and sweat secreted from the sweat glands. Let us introduce it in detail below.

The sebum membrane has important physiological functions for the skin and the entire body, mainly in the following aspects:

Barrier function: the sebum membrane can prevent excessive evaporation of skin moisture and prevent the entry of large amounts of external moisture and certain substances. As a result, the skin's moisture content remains normal.

Moisturizes the skin. The sebum film is emulsified by sebum and water. The lipid part can make the skin flexible, smooth and shiny; the water in the sebum film can keep the skin moist and prevent it from drying out.

Anti-infection effect: some free fatty acids in the sebum film can induce the growth of certain pathogenic microorganisms and have a self-purification effect on the skin.

Protecting the sebum film As mentioned above, the pH value of the sebum film is between 4.5 and 6.5, so how do we protect this thin sebum film? First of all, we need to choose a weakly acidic facial cleanser, and then how to identify whether a facial cleanser is weakly acidic? Don't listen to the salesperson, judge for yourself, add water and rub, if the bubbles are of different sizes or are too large, we should be careful, such facial cleanser is alkaline, and when we use it, our face will feel tight. If used for a long time, the acid and alkali will be neutralized, and our sebum film will no longer exist. Not only will it not achieve the effect we want to protect, but it will damage our skin. If the bubbles are fine, then the facial cleanser is weakly acidic and can be used with confidence.