Beauty Note | Occlusive Ingredient

The only way to prevent water loss from skin is to form a temporary barrier over the skin, which is similar to on how a sunblock forms a protective shield over the skin in order to block UV rays. This  barrier will be able to keep water molecules trapped inside the skin, thus reducing water evaporation.

Chemically speaking, occlusive is the ingredient that physically block trans-epidermal water loss (TEWL) by creating a temporary hydrophobic barrier on top layer of the skin. It is a non-water loving ingredient that made up of large molecules, making it unable to penetrate deep into the skin. That is why it only sits right on top of the skin, creating a barrier.

As it is hydrophobic, it repels water molecules, meaning that it does not increase moisture level of the skin. It only prevents water reserves from being drained by external stressors such as dry environment. This will prevent dehydration of the skin. It also acts as a protective barrier by preventing harmful foreign substance from entering the skin.

Illustration on how occlusive works on skin.

Occlusive ingredient is mainly lipid (oil) based, which means that it will give a thick, greasy and heavy feel post application. It diffuses into the intercellular lipid, contributes to the matrix between corneocytes within stratum corneum.

Below are some of the examples of occlusive ingredients: