In scientific terms, your skin is technically “dry” when its moisture level is less than 10%. That’s when you’re most likely to apply body lotion.
But how does moisturizers’ skin-smoothing magic work in the first place?
Cracked, flaky, and dry skin which tends to occur when humidity drops in the chilly months is known by a scientific name: transepidermal water loss, or TEWL.
At its simplest, TEWL is a measure of how much water seeps from the inside of the body through the different layers of the skin and out into the atmosphere.
Here’s how moisturizers work:
There are three different layers of the skin:
- The outer layer (epidermis)
- Middle layer (dermis)
- Lower layer (hypodermis or fatty layer)
Moisture is delivered to the skin via blood vessels, but they only supply moisture to the middle layer of the skin — the dermis. From there, water travels upward and outward through the epidermis before evaporating into the atmosphere.
This evaporation causes skin to crack and flake. This process happens constantly, but skin isn’t always dry. That’s because the dryer the air the more moisture it will pull from your skin.
Moisturizers work in two main ways; either they trap moisture in your skin to prevent moisture from escaping, or they restore moisture in the outer layer of skin that’s already been lost.
Water: Most moisturizers are oil-in-water emulsions.
Occlusives: Petrolatum and oily substances are sometimes referred to as occlusives because they block the evaporation of water.
Humectants: Theoretically, humectants pull water into the stratum corneum both from the air and from deeper layers of the skin.
Emollients: Emollients don’t moisturize but make the skin feel smooth.
Vitamins: Vit. A and C reduce fine lines and wrinkles by stimulating the production of collagen.
Menthol: Although menthol doesn’t attack the underlying problem, the cooling sensation does seem to cancel out the itching sensation.
So don’t forget to moisturize!
About the Author: Dr. Donika Vata is a medical doctor from Ferizaj, Kosovo. She studied general medicine from University of Hasan Prishtina.
She has been writing about medical and skincare related issue in journals, social media websites, and books. She was working for some well reputed clinics such as Telehealth Pro- Online consultations, German Cancer Center, and AppLMD. Dr. Donika was also volunteering in the Covid-19 pandemic.
Currently, she is working as a medical doctor and researcher in a dermatology clinic.