When we discuss the skin barrier, we are referring to the stratum corneum, which is the outermost layer of the skin. This layer serves as a direct barrier between our internal environment and the outside world, protecting our internal system from external irritants like pollution, toxins, microorganisms, and allergens. One of its other functions is to regulate transepidermal water loss (TEWL), also known as water loss through the skin. Both of these functions are vital to our survival and health, so it's important that we take good care of the stratum corneum.

Our skin is typically biologically healthy when we are young and functions without too many problems. As lipid production decreases with age, our skin's natural protective barrier weakens and makes us more susceptible to external aggressors. This affects both our skin's natural ability to repair itself and its barrier function, making our skin more sensitive and dehydrated. The skin barrier is also susceptible to the skincare products it comes into contact with. For example, if you are using harsh sulphate-based cleansers, skincare formulated at the incorrect pH, or that contains irritating ingredients, these factors will all contribute to damage to this protective barrier. However, you can simultaneously repair that barrier and lower inflammation by adopting a ceramide-rich skincare regimen. By using gentle, low-foaming cleansers and using skincare containing ceramides and other highly moisturizing ingredients, you can help to restore your skin's hydration from the outside, minimize the appearance of aging, improve skin texture and tone, and help to prevent and treat inflammatory skin conditions like acne, dermatitis and eczema.

Like collagen and elastin, ceramides are found in the skin naturally, but as we age, the production of essential lipids (oils) decreases. Although there are many different types of lipids secreted by the skin, ceramides, cholesterol, and fatty acids are the predominant types, and they play a critical role in the overall health of our skin by promoting cellular turnover and preserving a healthy permeable barrier function [1].

Increased skin roughness, uncomfortable tightness, a dull skin tone, an increase in blemishes, dermatitis and a loss of facial fullness are all symptoms of lipid depletion. A healthy lipid layer aids in the skin's ability to self-heal, which enhances hydration, reduces the appearance of fine lines and wrinkles, and improves skin tone and texture. Our skin runs the risk of accelerated ageing without this essential lipid layer [2].

Because of this, it is crucial to include topical ceramides, fatty acids, and cholesterol in your skincare regimen. In clinical studies, ceramides have been proven to help address dryness and water loss in the skin, restore the skin’s natural protective function, and combat wrinkles [3]. When applied topically, they increase hydration, make the skin feel softer and more supple, strengthen the skin's natural barrier, relieve itching and irritation, and calm rashes, redness, irritation, and dermatitis. They even reduce the appearance of fine lines and wrinkles.

Who would benefit from ceramides in their routine?

All skin types can benefit from topical ceramides, but those with extremely sensitive skin reap the greatest rewards. Skincare containing topical ceramides can be a godsend for strengthening the skin barrier and enhancing the overall health and appearance of the skin. Those with eczema typically have a diminished skin barrier with insufficient ceramide levels. The diminished barrier function that results from a drop in ceramide concentration can also affect other skin conditions besides eczema, including rosacea and acne [4]. So, if your skin is particularly irritated, it's probably time to focus on ceramide-containing products, as they are one of the most efficient types of skincare on the market.

You don't need to be concerned about what ingredients you mix ceramides with. Your skin is likely to tolerate any potentially irritating ingredient in a skincare product better if you combine it with ceramides, which makes them an excellent choice if you are using strong exfoliants, retinoids, or acne treatment ingredients, as the improvement in the skin's barrier function makes these potentially irritating ingredients much more tolerable.

What to look for in ceramide-containing skincare:

Many products that boast they contain ceramides actually only contain only one or two individual ceramide molecules in very low concentrations that are unlikely to be effective. The best skincare products contain a mixture of ceramides (there are five different types present in the skin) and ceramide precursors, (so the skin can make its own). The ideal concentration (depending on the supplier) is 2%, so they should sit near the top of an INCI list. In addition, ceramides must be combined with other lipids in the proper ratio for them to function at their best. Recent studies have revealed that while ceramides, cholesterol, and fatty acids are all necessary for skin barrier repair on their own, but they all function best when combined. The complex composition of the lipids in the human stratum corneum is found to be 50% ceramides, 24% cholesterol, and 15% free fatty acids [5].

How often can you use ceramides?

Ceramides are so gentle and hydrating that there is no restriction on how frequently you can apply them, unlike some ingredients. Using them daily will maintain hydrated and soft skin for skin types with normal skin. For dry, sensitive, or rash-prone skin types like me, twice a day is even better. When it comes to ceramides, more is best.

The simplest way to build up the skin's lipid layer is to choose specially formulated products that work synergistically to restore the skin's external barrier by offering superior hydration, assisting the skin's natural ability to self-heal, nourishing the skin, and lowering the risk of accelerated ageing. This concept is what the entire Eunoia range was formulated around, and all products contain the highest concentration of ceramides, cholesterol, fatty acids, and ceramide precursors in the optimal ratio. All products have complementary ingredients like niacinamide (Vitamin B3), panthenol (Vitamin B5), hyaluronic acid, and pre-biotics and post-biotics to further rebuild and nourish the skin's protective moisture barrier further.

 References:

1. Coderch L, López O, de la Maza A, Parra JL. Ceramides and skin function. Am J Clin Dermatol. 2003;4(2):107-29. doi: 10.2165/00128071-200304020-00004. PMID: 12553851.
   
   
2. Choi MJ, Maibach HI. Role of ceramides in barrier function of healthy and diseased skin. Am J Clin Dermatol. 2005;6(4):215-23. doi: 10.2165/00128071-200506040-00002. PMID: 16060709.
   
   
3. Rosso JD, Zeichner J, Alexis A, Cohen D, Berson D. Understanding the Epidermal Barrier in Healthy and Compromised Skin: Clinically Relevant Information for the Dermatology Practitioner: Proceedings of an Expert Panel Roundtable Meeting. J Clin Aesthet Dermatol. 2016 Apr;9(4 Suppl 1):S2-S8. Epub 2016 Apr 1. PMID: 28936279; PMCID: PMC5608132.
   
   
4. Sophie Knox, Niamh M. O’Boyle, Skin lipids in health and disease: A review, Chemistry and Physics of Lipids, olume 236, 2021, 105055, ISSN 0009-3084, https://doi.org/10.1016/j.chemphyslip.2021.105055.
   
   
5. Ananthapadmanabhan, K., Mukherjee, S. and Chandar, P. (2013), Stratum corneum fatty acids: their critical role in preserving barrier integrity during cleansing. Int J Cosmet Sci, 35: 337-345. https://doi.org/10.1111/ics.12042
   
   
6. Zettersten EM, Ghadially R, Feingold KR, Crumrine D, Elias PM. Optimal ratios of topical stratum corneum lipids improve barrier recovery in chronologically aged skin. J Am Acad Dermatol. 1997 Sep;37(3 Pt 1):403-8. doi: 10.1016/s0190-9622(97)70140-3. PMID: 9308554.
   
   
7. Proksch E, Holleran WM, Menon GK, Elias PM, Feingold KR. Barrier function regulates epidermal lipid and DNA synthesis. Br J Dermatol. 1993 May;128(5):473-82. doi: 10.1111/j.1365-2133.1993.tb00222.x. PMID: 8504036.