What is the benefit of applying an after-sun lotion?

Although the sun is a source of benefits for the skin, it is important not to overlook the dangers of long and frequent exposures. Indeed, these can have several harmful effects on the structure and function of the skin and can significantly damage the skin barrier. Formulated to soothe skin weakened by the sun and available in various forms, after-sun products have multiple virtues:

• After-sun products help to rehydrate the skin.

  It is normal for the dermis to lose between 300 and 400 mL of water per day, passing through diffusion across the epidermis and then evaporating once it reaches the surface of the stratum corneum. This physiological process is essential: it promotes hydration of the superficial layers of the skin and allows the rise of nutritive substances from the dermis to the epidermis, a crucial element considering the latter is not vascularised. However, during sun exposure, insensible water losses increase and the water balance is disrupted.

  To restore it, it is beneficial to apply a moisturising treatment with a fresh texture, such as an after-sun lotion. This product notably helps to restore the hydrolipidic film present on the skin's surface, which plays a protective role. The primary function of the after-sun lotion is therefore to combat skin dehydration and prevent the skin from peeling.

• After-sun products help to re-lipidise the epidermis.

  During exposure to UV light, the entire skin barrier becomes destabilised and a loss of lipid function can be observed. These compounds of the intercellular cement play a crucial role in skin protection and in preventing dehydration. By promoting the production of free radicals in the skin, UV rays disrupt the horny layer. Indeed, free radicals react with lipids in a process known as lipid peroxidation. This reaction generates inflammatory by-products such as the superoxide anion, which can damage skin tissues and DNA.

  Often rich in lipid-replenishing active ingredients such as ceramides or vegetable oils, after-sun products help to nourish the epidermis and restore the protective function of the skin barrier. They thus assist in maintaining hydration and contribute to the repair of cells damaged by UV rays.

• After-sun products reduce inflammation.

  UV rays tend to stimulate skin inflammation through several mechanisms, notably by increasing the levels of oxidative stress in cells. Indeed, the free radicals they generate can activate certain nuclear factors such as the AP-1 transcription factor, involved in the release of cytokines, which intervene at different levels of inflammation and promote redness and swelling. They particularly encourage the synthesis of adhesion molecules, immunoglobulins that play a significant role in controlling the circulation of leukocytes.

  After-sun products are soothing formulations, based on anti-inflammatory ingredients such as calendula, aloe vera, or panthenol. By combating inflammation, these various active ingredients help to soothe skin weakened by the sun while limiting sunburn. This action is also facilitated by the cool texture that most after-sun products possess.

• After-sun products extend the tan.

  One of the reasons why sun exposure is so cherished is the lovely tan it allows one to achieve. To maintain it for as long as possible, the application of an after-sun product can prove to be an ally. Indeed, by enhancing the skin's hydration, this care prevents it from peeling, a factor that accelerates the loss of tan.