Do after-sun products protect against UV rays?

Do after-sun products protect against UV rays?

There are numerous treatments available to protect the skin and hair from the effects of the sun. Among these, we find sunscreens and after-sun products. While it is clear that the former protect against UV rays, the function of the latter is sometimes less obvious. Can after-sun products block UV rays? Discover their mode of action here.

Summary
Published May 29, 2024, updated on October 4, 2024, by Pauline, Chemical Engineer — 4 min read

After-sun: Can it replace sunscreen?

During holidays, it is common to enjoy the sun to tan and spend long hours at the beach. The skin is then exposed for entire hours to the harmful rays of the sun. These exposures constitute real aggressions for the skin which can react by developing redness, swelling, sunburn, dark spots, or even melanomas. Indeed, by penetrating the skin, UV rays alter the hydrolipidic film, destabilise the organisation of lipids in the stratum corneum, damage the structure of functional proteins in the dermis, and stimulate inflammatory processes.

To protect oneself from the dangers of the sun, the systematic and regularly renewed application of a sunscreen is essential.

The protection provided by sunscreens relies on their concentration of UV filters. Whether they are organic or mineral, they act as a filtering barrier on the surface of the skin, protecting it from the sun's rays. It is important to use a sun care product with a sun protection factor (SPF) of at least 30 to ensure adequate protection. For your information, an SPF 30 blocks approximately 96.7% of UVB rays, while an SPF 50 protects against 98.3% of UVB rays.

However, despite the UV protection provided by sun care products, some of the sun's rays still reach the epidermis and dermis. As mentioned earlier, UV rays have a drying effect on the skin and significantly increase insensible water loss. To counteract this dehydration, replenish the epidermis with lipids, and soothe the feeling of tightness, it is recommended to apply an after-sun product at the end of the day. Available in the form of cream, lotion, or mist, this care product comes in various formulations to suit all skin types.

However, while after-sun products are interesting solar products for taking care of your skin during the summer period, they do not contain UV filters and therefore cannot protect the skin from the sun's rays. As their name suggests, after-sun products are applied after exposure and cannot replace sunscreens, which are used before going out. Conversely, sunscreens cannot substitute for after-sun products because their formula does not contain, or does not contain enough, hydrating, nourishing, soothing, and repairing active ingredients.

After-sun products do not protect the skin from UV rays but limit their damage to the epidermis.

Sources

  • MOAN J. & al. Sun and sun beds: inducers of vitamin D and skin cancer. Anticancer research (2009).

  • PIOT B. & al. Effect of the sun on visible clinical signs of aging in Caucasian skin. Clinical, Cosmetic and Investigational Dermatology (2013).

  • BJÖRKLUND S. & al. The Effect of UVB Irradiation and Oxidative Stress on the Skin Barrier—A New Method to Evaluate Sun Protection Factor Based on Electrical Impedance Spectroscopy. Sensors (2019).

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