Understanding the structure of the skin, layer by layer, is key to providing it with what it needs for complete, optimal hydration.
Our skin’s first and main protective barrier is located in the stratum corneum, the top part of the epidermis. This barrier is capable of regulating water loss from our body and the absorption of what we apply on our skin. This barrier is made up of mature cells called corneocytes that act as “bricks” and the “cement” that binds them together is a mixture of mainly lipids. This mixture is what keeps the barrier strong and therefore skin healthy. Understanding its composition crucial to giving our skin what it needs in terms of hydration and nutrition:
1. Although factors such sex and age can cause some variations, triglycerides are the main component of our skin “cement”. Vegetable oils are considered a great source of triglycerides, hence why many are included in skincare formulas. Waxy molecules are another alternative, so including them in any beauty routine comes highly recommended for boosting skin hydration levels. A personal favourite of mine is jojoba oil, which from a chemical point of view, is actually a liquid wax (hence why it’s mistakenly called oil). However, a word of caution. Solely focusing on active ingredients should be considered a big no-no. Each and every ingredient included in a formula should be carefully considered. From consistency factors, emulsifiers, humectants, preservatives, viscosity modifiers to essential oils and perfumes. Everything must have a reason and even more so in the natural skincare world.
2. As squalene makes up approximate 10% of our skin’s oil (read, “cement”), it is not surprising it has found its way into many products. Nevertheless, it is a very unstable molecule, which is why a less oxidation-prone version, squalane, is used.
3. With all this talk of oils, you may be wondering why water is often listed as the first ingredient in your favourite moisturising cream, together with other aqueous extracts. The answer is simple. Our skin’s protective barrier also contains substances derived from sweat. In fact, many substances found in our blood plasma are also found in the aqueous film on the surface of the skin, also called the acid mantle or hydrolipic film (a combination of water and oil). This film contains amino acids (the building blocks of proteins), a carbohydrate called sodium PCA, urea, and various lactic acid salts.
Our skin’s protective barrier is subjected to climatic and chemical aggressions on a daily basis. With this in mind and taking into consideration all of the above, it makes sense to include each of the components mentioned in formulas designed to improve skin hydration and health.