TEWL. When you say it out loud, it sounds like “tool,” but it actually stands for trans-epidermal water loss. It’s simply the technical term for the amount of water that leaves your body through your skin (your epidermis) by diffusion and evaporation.
You lose water through your skin all the time, but the amount lost changes depending on the atmospheric conditions and how damaged or hydrated your skin is.
Here in California, where the climate is almost always dry, and particularly in the winter, when the temperatures drop, it is something you need to be especially aware of, because dry and windy climates increase TEWL. TEWL also increases when there is not enough water in our skin or when there is damage (burns, wounds, sunburns, etc.) to our skin.
So, what can we do to try to reduce this water loss? First off, we can stay away from things that damage our skin, like excessive sun or wind, temperature extremes, or even really scratchy sweaters. We can use humidifiers in our homes, if we live in a place where the humidity is below the 40-60% ideal. Perhaps the easiest thing to do is to apply things to our skin that will keep the water in.
Thick moisturizing creams (those with nice butters, for example) create a barrier, referred to as an occlusion in the science world, that make it difficult for water to leave the epidermis, reducing TEWL. However, that film on the skin disappears after a few hours, so it is important to re-apply the lotion. If you don’t want to use a cream, you can use anything with high levels of gamma-linoleic acid (GLA), an omega-6 fatty acid. A study conducted by the National Institute of Health on babies with dermatitis showed that this fatty acid is useful in maintaining the skin’s water content, and promoting recovery from dermatitis. GLA has, several times, been shown to be one of the most effective agents for the treatment of skin disorders and the maintenance of healthy skin (https://www.ncbi.nlm.nih.gov/pubmed/8095744). But where can you find gamma-linoleic acid? Many oils contain it naturally, and borage oil has one of the highest concentrations (at 20-24%).
Personally, I love this oil. When I feel my skin getting too dry, I apply borage oil before bed and, when I wake up the next day, my skin magically feels so hydrated and fresh. If you are suffering from dry skin, you should definitely try this oil. The only thing I’m not a huge fan of in this oil is its slightly briny scent, which I usually cover with Jasmine or Rose (or any other) essential oils. It works like magic. Don’t let the off-putting scent stop you from getting all the great benefits that borage oil gives your skin!
By Gabrielle Candes