Here’s a simplified version for those who just want the gist:
Your skin barrier is like a protective wall—it keeps moisture in, blocks harmful stuff like UV rays and bacteria, and keeps your skin healthy and glowing. But aging, harsh soaps, and dry environments can weaken it, leading to dryness, sensitivity, or irritation.
Here’s the deal:
- Stop using harsh soaps—they wreck your skin’s natural defenses.
- Instead, use gentle, pH-balanced cleansers to preserve your skin's acidity.
- Add hydroxy acids (like glycolic acid) to boost your skin’s natural repair process.
- Strengthen your barrier with niacinamide and panthenol.
- Moisturize smart: Look for ceramides, hyaluronic acid, and squalane to hydrate and repair.
- Put on antioxidants (like Vitamin C) to fight skin barrier damage from the sun and pollution.
*If you think your skin barrier may already be damaged, we recommend starting with these three products: Sheer Silk (for daily cleansing) plus Hydrator B5 Gel with Panthenol and Hydro Relief moisturizer to repair the barrier. You'll start feeling improvement within 2 weeks of daily use.
Bottom line: A healthy skin barrier = glowing, resilient skin. Take care of it, and it’ll take care of you.
Here is the full, technical version with references:
The skin barrier is mainly comprised of the Stratum Corneum which is the visible outermost layer of your skin although deeper skin layers of the epidermis also contribute.
Image source: National Eczema Association
A healthy skin barrier has great importance for health that goes beyond physical appearance.
First, a healthy skin barrier presents a largely waterproof barrier that holds in water and helps preserve the water-rich environment of your body. The Stratum Corneum is sometimes visualized as a ‘bricks’ and ‘mortar’ model.
The bricks are flattened skin cells called ‘corneocytes’ which are full of a hard protein called keratin as well as natural moisturizing factors. Keratin is the same protein found in hair and nails.
The mortar consists of lipids which are oily, fatty, and waxy substances. Specifically, it is composed of 50% ceramides, 25% cholesterol or cholesterol sulfate, and 15% fatty acids. The mortar makes the Stratum Corneum water-proof.
Skin excretions such as sebum contribute additional lipids (Del Rosso et al. 2016). Skin acidity is also required for proper formation of the “mortar” of the Stratum Corneum as enzymes that produce ceramides function best at an acidic pH (Lee et al 2006) while enzymes that break down ceramides function best at a high skin pH (Ali and Yosipovitch 2013).
Second, a healthy skin barrier helps protect your body from the harmful effects of damaging UV rays and other environmental hazards such as smoke which generate free radicals. Free radicals are like bullets destroying proteins, lipids, and DNA which can lead to cell damage and cancers. Free-radical neutralizing antioxidants such as Vitamin C, Vitamin E, and glutathione are naturally present in high concentrations in the skin for this purpose. However, natural antioxidant levels decline with aging (Pullar et al. 2017).
Third, a healthy skin barrier keeps out pathogens such as bacteria, yeast, viruses and allergens. The integrity of the bricks and mortar of the Stratum Corneum is important as a natural physical barrier to microbes. For example, think of when you have a cut in your skin. This allows bacteria to invade your body and can lead to infection. Also important however is the natural acidity of the Stratum Corneum which limits the growth of harmful microbes. Natural antimicrobial peptides and lipids in the Stratum Corneum, as well as acidic and antimicrobial excretions from sebum and sweat also contribute to antimicrobial protection (Lee et al. 2006, Ali and Yosipovitch 2013).
Signs of a weakened skin barrier include dry and flaky skin, sensitive skin, red and inflamed skin, or skin conditions such as eczema. Aging is associated with progressive weakening of the skin barrier and increasing skin pH. Dry skin is a near universal complaint in the elderly (Hahnel et al. 2017). Improper washing with soaps can also weaken the skin barrier. This is because soaps are alkaline and so raise the pH of the skin. This decreases ceramide levels and reduces antimicrobial protection (Lambers et al. 2006).
Regardless of the cause, choosing the right topical skincare products can help repair and reinforce the skin barrier. Including picking the right pH balanced cleanser, certain vitamins such as niacinamide (Vitamin B3) and panthenol (provitamin B5) have also been scientifically shown to help increase the production of proteins and lipids such as ceramides that make up the ‘bricks’ and ‘mortar’ in aged skin (Gehring 2004). In those with increased skin pH, acidifying the skin barrier with hydroxy acids has been shown to increase the production of ceramides as well as help fight microbes (Hachem et al. 2010, Rawlings et al. 1996).
Moisturizers can also supplement the “mortar” by supplementing skin-identical lipids such as ceramides, cholesterol and free fatty acids, as well as squalane which mimics squalene in sebum (Kahraman et al. 2019). Moisturizers also contain humectants which hold water, and occlusives which form a water-proof barrier on top of the skin to help reinforce the skin barrier. Topical antioxidant supplementation can restore antioxidant levels in aged skin (Pullar et al. 2017).
Here is our cheat sheet of Do’s and Don’ts to repair and reinforce a weakened skin barrier.
Do’s and Don’ts:
1. Don’t use soaps or harsh sulfate cleansers
2. Do use mild cleansers that have a pH below 6
3. Do use hydroxy acid serums and creams (i.e. glycolic acid)
4. Do use topical antioxidant serums (i.e. Vitamin C E Ferulic)
5. Do use panthenol and niacinamide to strengthen the skin barrier
6. Moisturizers with humectants like hyaluronic acid, NMFs, glycerin, amino acids, and peptides will help dry skin.
7. Moisturizers with skin-identical lipids such as ceramides and squalane will help repair a weakened skin barrier
8. For very dry skin, do use moisturizers with occlusives with waxy components such as shea butter, jojoba oil, or jojoba esters if you prefer plant-based skincare. Petroleum, mineral oil, and silicones are other good occlusives.
References:
Ali SM, Yosipovitch (2013). “Skin pH: From Basic Science to Basic Skin Care.” Acta Derm Venereol 93: 261-267.
Del Rosso J, Zeichner J, Alexis A, Cohen D, Berson D (2016). “Understanding the Epidermal Barrier in Health and Compromised Skin: Clinically Relevant Information for the Dermatology Practitioner.” J Clin Aesthetic Dermatol 9(4): Supplement 1.
Gehring W (2004). “Nicotinic acid/ niacinamide and the skin.” Journal of Cosmetic Dermatology 3:88-93.
Kahraman E, Kaykin M, Sahin Bektay H, Gungor S (2019). “Recent Advanced of Topical Application of Ceramides to Restore Barrier Function of Skin.” Cosmetics 6:52. doi: 10.3390/cosmetics6030052.
Hachem JP, Roelandt T, Schurer N, Pu X, Fluhr J, Giddelo C, Man MQ, Crumrine D, Roseeuw D, Feinhold KR, Mauro T, Elias PM (2010). “Acute Acidification of Stratum Corneum Membrane Domains Using Polyhydroxy Acids Improves Lipid Processing and Inhibits Degradation of Corneodesmosomes.” Journal of Investigative Dermatology. 130: 500-510.
Hahnel E, Blume-Peytavi U, Trojahn C, Kottner J (2017). “Associations between skin barrier characteristics, skin conditions and health of aged nursing home residents: a multi-center prevalence and correlation study.” BMC Geriatrics 17:263. doi: 10.1186/s12877-017-0655-5.
Lee SH, Jeong SK, Ahn SK (2006). “An Update of the Defensive Barrier Function of Skin.” Yonsei Medical Journal 47(3): 293-306.
Pullar JM, Carr AC, Vissers MCM (2017). “The Roles of Vitamin C in Skin Health.” Nutrients. 9:866. doi:10.3390/nu9080866.
Rawlings AV, Davies A, Carlomusto M, Pillai S, Zhang K, Kosturko R et al. (1996) Effect of lactic acid isomers on keratinocyte ceramide synthesis, stratum corneum lipid levels and stratum corneum barrier function. Arch Dermatol Res 288:383–90
