How long in advance should you apply sunscreen? What is the film-forming agent?

Sunscreen is an essential sun protection product, especially in summer. However, there are some things to pay attention to when applying sunscreen. For example, it usually needs to be applied in advance. Do you know this? Also, how long in advance should you apply sunscreen? Let’s learn more about it.

How long in advance should you apply sunscreen?

Apply it about 15-20 minutes in advance. Because sunscreen does not work as soon as it is applied. After being applied to the skin, it needs a certain amount of time to absorb the sunscreen ingredients in the sunscreen so that it can settle in the basal layer of the skin and form a protective film, which can effectively block the absorption of light by melanocytes.

What is sunscreen film?

Simply put, waiting for the sunscreen to form a film means waiting for the water, alcohol, volatile oils and other ingredients in the sunscreen to completely evaporate. After these ingredients evaporate, the coating of sunscreen becomes thinner, and the layer of sunscreen just applied on your skin is basically left with the film-former and the sunscreen in the film-former. This is the protective film everyone needs! This can allow the sunscreen particles to be arranged more closely together, making it difficult for ultraviolet rays to pass through, and can provide better sunscreen effects.

It is recommended to apply sunscreen before going out. Our skin surface is uneven (with skin bumps and grooves), so it is not easy to make sunscreen products evenly cover the skin. When sunscreen is first applied to the face, the coating is relatively thick. When the water has not evaporated and the sunscreen is dispersed more sparsely, the ultraviolet rays at this time can easily penetrate this layer of sunscreen protection.

Because this evaporation process takes about 5 to 10 minutes, and the specific time depends on your environment and the selection and ratio of volatile ingredients in the product formula. For example, if the humidity is high, evaporation will definitely be slower, and it will take longer to form a film; if the alcohol content is higher, it will evaporate faster, and the film will naturally form faster. Therefore, how many minutes you should wait before going out after applying sunscreen actually varies from person to person! In addition to sunscreen, other cosmetics that require film formation can basically be understood in this way, such as foundation, mascara, eyeliner, lipstick, etc.

Do not mix sunscreens

Whatever sunscreen you are using when you go out that day, bring that sunscreen with you. Be sure not to mix different brands of sunscreen. Because each brand of sunscreen has different ingredients, if you mix sunscreens together, not only will the sunscreens repel each other, but they will also fail to achieve the ideal sun protection effect and may even cause allergies.