Why should you apply sunscreen in advance and how long should you apply it before going out?

Sunscreen is also a kind of skin care product, which many people know about. So why do we need to apply sunscreen in advance? How long before going out should you apply sunscreen?

Why should you apply sunscreen in advance?

Because sunscreen products use two types of sunscreens to achieve the effect of sun protection, one is physical and the other is chemical. Physical sunscreen acts as a barrier on the skin and takes some time to form a film. Chemical sunscreens take longer to penetrate because they are absorbed by the skin and then release UV rays. So sunscreen must be applied in advance.

How long before going out should you apply sunscreen?

Be sure to apply sunscreen about 20 minutes before going out, because sunscreen does not have a sunscreen effect as soon as it is applied. After sunscreen is applied to the skin, it needs a certain amount of time to absorb the sunscreen ingredients in the sunscreen so that it can be deposited in the basal layer of the skin to form a protective film, which can effectively block the absorption of light by melanocytes.

This is the reason why you should apply sunscreen in advance. Generally, it is best to apply it 20 minutes before going out.