Regimen Lab Skincare Encyclopedia ?

Ceramides

*Preliminary Lab Notes* - Full Entry Under Development

Ingredient Profile

Common Name: Ceramides
INCI: Ceramides
Source: Sweet Potato, Wheat, Brown Rice
Ceramide Molecule

kligman ingredient evaluation

Penetration: Under analysis
Biochemical Mechanism: Under analysis
Level of Evidence: Under analysis

Regimen's Take

Ceramides are a key part of the skin's moisture barrier, a critical structure that keeps the good (e.g. water) in and the bad (e.g. foreign bodies, pathogens) out. In skincare, ceramides can be a powerful means of repairing and boosting the skin barrier. We think everyone should prioritize a healthy skin barrier and ceramides are a big part of this. HOWEVER, most products we have found do not use ceramides probably, and done so, products with ceramides have been shown to REDUCE barrier repair. when you apply a typical product on your skin (petroleum, mineral oil, squalene) it either stays on top of your skin or mixes into your cement lipids - emollients goal is to fill the gaps. Problem - those ingredients don't really penetrate the skin - and they relatively quickly evaporate, wash off, OR they mix into the cement layer. While this can make skin feel good, they in fact disrupt skin barrier repair. Your cement isn't a static structure in your skin, so has a double purpose to replenish immediately AND be stored as 'raw material' for your body to use later in ceramide synthesis. When you use lipid-compatible products.s

TLDR

Studies show that ceramides must be used in a 3:1:1:1 ratio with cholesterol, essential and non-essential fatty acids. This ratio mimics the skin barrier's own composition, and using products not formulated in this ratio can actually worsen barrier repair, as the skin now has to compensate to restore the ratio. Also, studies show that ceramides in this ratio should be in a 2.5% concentration. Many products on the market use a pre-made 'ceramide complex' - and so a claim of "3% ceramdie complex" actually results in .035% ceramides in the final product, there is no known clinical benefit to ceramides in this low amount.
Ceramides are a powerful skincare ingredient, particularly when used in skin barrier repair and hydration. There is a wealth of scientific study behind their effectiveness, but formulated improperly they can be ineffective or even harm the skin, so consumers should look out for products formulated in a skin mimetic ratio and no less than 2% ceramides, optimally 2.5% according to recent studies.
 TMI:

Think of skin like a brick wall, really it’s a moisture barrier that keeps water in and foreign bodies / pathogens out. Ceramides are a key part of the cement that fills the gaps between the ‘bricks’ in this system. That cement “cement lipids” is actually a composition of 50% ceramides, 25% cholesterol, 10-15% fatty acids and 5% various lipids. Your body produces ceramides on its own, which come from the base layers of the skin, and are released at the top layer of your skin and make their way into the cement lipids. Your body is constantly doing this to repair and replenish the moisture barrier.

Moisturizers with Ceramides in a specific ratio (3:1:1:1) to Cholesterol and Essential and Non-Essential Fatty acids help repair damaged barrier.

• 2% Ceramides in a 3:1:1:1 ratio with Cholesterol, Essential and Non-Essential Fatty Acids help strengthen the moisture barrier.
• 2% Isosorbide Dicaprylate + 2% Glycerin + 2% Glyceryl Glucoside activates more efficient hydration.
• Squalane and Triglycerides help retain this moisture.
• 2% Ursolic Acid Liposomes support the skin’s moisture barrier.
•1% Bisabolol soothes irritated and inflamed skin.

Think of skin like a brick wall, really it’s a moisture barrier that keeps water in and foreign bodies / pathogens out. Ceramides are a key part of the cement that fills the gaps between the ‘bricks’ in this system. That cement “cement lipids” is actually a composition of 50% ceramides, 25% cholesterol, 10-15% fatty acids and 5% various lipids. Your body produces ceramides on its own, which come from the base layers of the skin, and are released at the top layer of your skin and make their way into the cement lipids. Your body is constantly doing this to repair and replenish the moisture barrier. Moisturizers with Ceramides in a specific ratio (3:1:1:1) to Cholesterol and Essential and Non-Essential Fatty acids help repair damaged barrier.



What are they?
Ceramides are composed of a sphingosine or sphingoid head in an amide linkage with a fatty acid. What does that mean? It just means that it has a polar (water loving) head and a non-polar (water disliking) tail. They are produced in the lower part of your skin and together with cholesterol, fatty acids and some other free sterols, they are transported in a lamellar formation (alternating layers) to the stratum granulosum-stratum corneum interphase. They are then processed by skin enzymes so they can integrate with the existing cement lipid. These enzymes are dependent on pH (activity highest at 5.1-5.6) and hydration level.(Coderch, López, de la Maza & Parra, 2003). Cer 1 and Cer 3, due to their high carbon number, work synergistically to restore barrier protection. The resulting processed lamellar layer has a long Cer 1 that allows the new lamellar layer to integrate with the existing one. Imagine Cer 1 as a Velcro that is not dependent on whatever orientation it may be. (Meckfessel & Brandt, 2014)



How do they work?
We all know that the skin is your first protection against harmful substances in the environment, but how does it exactly protect us from foreign bodies and at the same time prevent water loss?

Review skin composition here.


Stratum corneum, which is the uppermost layer of the skin, is composed 70% proteins, 15% water and 15% lipids. The most prominent feature in the stratum corneum are dead keratinocytes tightly held together forming the horny layer (not the sexual type but rather horny as in horns and nails). In between these compact dead cells are layers of organized lipids which are composed of ceramides, cholesterol, fatty acids, and free sterols. Some of these ceramides are covalently (tightly) bound to the corneocytes, which tightly binds the cement lipid layer to the corneocytes forming a lamellar layer. This tight interface of hydrophobic corneocytes and ceramides makes it really hard for hydrophilic substances to pass through. Another function of these covalently bonded ceramides is to serve as a template for the formation of the intercellular lipid layer. A recent study showed that the amount of covalently bound ceramides is directly correlated to TEWL and therefore barrier function.(Meguro, Arai, Masukawa, Uie & Tokimitsu, 2000)

Ceramides Testing 1 2 3/ let’s see if this works out.
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The Skincare Encyclopedia aims to improve public understanding of the biology and chemistry of skincare. The Encyclopedia is rooted in core scientific principles and extensive research, in many cases in collaboration with the authors of the original studies referenced. This is a project of Regimen Lab, maintained by a group of multidisciplinary scientists, MDs, and researchers.