Bioderma Photoderm Fluide Max Sun Active Defense + AP SPF 100 Versus Bioderma Photoderm After-Sun Gel-Crème

Fructooligosaccharides (FOS) are a type of prebiotic sugar with humectant and skin conditioning properties. As a humectant, they help attract and hold moisture in the skin.

FOS essentially acts as a food source for the "good" bacteria on your skin and make it harder for "bad" bacteria to thrive. A 2022 study using a reconstructured human skin model found that just 1% of FOS was enough to shift the bacteria balance in favor of beneficial species. This suggests it could help support a healthier skin microbiome over time.

Laminaria Ochroleuca Extract is a type of kelp. It helps sooth and hydrate the skin. By nourishing the skin's barrier, it may also help relieve irritation.

This ingredient contains both lipids and antioxidants. The lipids nourish the skin's barrier. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells.

Mannitol is a sugar alcohol. It is a humectant and moisturizes the skin. In vitro (not tested on a living organism), mannitol displays antioxidant properties.

When found in aqueous solutions, mannitol tends to become acidic. This is because it loses a hydrogen ion. This is why mannitol can often be found with pH adjusting ingredients, such as sodium bicarbonate.

Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:

Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.

We don't have a description for Rhamnose yet.

Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.

Its main functions are to maintain the pH of a product and neutralize metal ions.

Sodium Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.

In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

Xylitol is a humectant and prebiotic. It can help with dry skin.

In studies, xylitol has been shown to improve dry skin. It decreased transepidermal water loss, or when water passes through the skin and evaporates. Xylitol also showed to help improve the biomechanical properties of the skin barrier.