Mode d'application crème solaire.

How to apply sunscreen?

Premature aging, skin cancer, burns... The sun can prove dangerous for the skin, regardless of the weather and whether you are indoors or outdoors. That's why it's necessary to block all UV rays. Therefore, the daily use of sunscreen is essential. Even though the importance of applying sunscreen every day seems to be understood by most people, questions still remain, particularly about its application: how to apply it correctly? How much to use? Where should it be applied?

Sunscreen: What is its purpose?

Sunscreen protections come in various forms: oil, lotion, cream, milk, gel... Their purpose is to filter the sun's UV rays that penetrate the epidermis and dermis, thereby reducing their exposure to the skin. UVB rays, which cause burns, act on the level of the epidermis. UVA rays, on the other hand, generate free radicals and cause cell damage leading to photoaging. Thus, sunscreens are used to prevent sunburns, and also minimize skin aging and prevent the risk of skin cancer.

Sunscreen: How to apply it correctly?

When applying your sunscreen, the most crucial aspect is to apply the correct amount of product to ensure its effectiveness, as well as a good absorption spectrum specific to the filter used.

You must apply it in sufficient quantity, which is 2 mg per cm² of skin, to achieve the protection index value indicated on the label. This quantity equates to approximately 35 g of sun protection over the entire body for an adult of standard size and weight, which is two 200 mL bottles of sunscreen per person per week.

Indeed, studies have shown that consumers only use about a quarter of this amount, or 0.5 mg per cm², in real life. However, the SPF indicated on the label is related to the amount of product applied. This means that the SPF spread on the consumer's skin is lower than expected.

After applying your sunscreen, wait about twenty minutes before exposing yourself to the sun or layering other products on top. This is the time needed to create a protective barrier against UV rays. Then, the application of your sun protection should be done approximately every two hours. Indeed, the value of the SPF decreases with the impact of environmental factors, such as perspiration, swimming, skin rubbing against the bath towel or sand, and photodegradation.

For better protection of your skin, you should also apply sunscreen to areas such as the eyelids, nose, ears, lips, etc... areas that are often overlooked. Lastly, we advise you to choose a sunscreen that is suitable for your skin type : fair skin requires a sun product with a high SPF, while a lower UV protection index is recommended for darker and tanned skin.

Tip : If you want to enhance your protection, use a serum rich in antioxidants (vitamin C, ferulic acid, resveratrol, tocopherol, thyme essential oil, etc...) before your sunscreen. Indeed, this treatment will help protect the skin against external aggressions (pollution, smoking, sun exposure, etc...) that promote the development of free radicals, responsible for photo-aging. You can, for example, opt for our radiance serum highly concentrated in vitamin C (11%) and in Albizia julibrissin extract (3%).

Sources

  • LIPOZENCIC J. & al. Sunscreens : the ultimate cosmetic. Acta Dermatovenerologica Croatica (2003).

  • FWULF H. C. & al. The relation between sun protection factor and amount of sunscreen applied in vivo. British Journal of Dermatology (2007).

  • MOHAMMAD T. F. & al. Sunscreens and photoaging: a review of current literature. American Journal of Clinical Dermatology (2021).

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