Type of Ingredient: Skin-conditioning agent and an emulsifier.
Main Benefits: According to the National Institutes of Health, lipids fill the spaces between skin cells for instant hydration.
Who Should Use It: People who have dry and aging skin.
Ideal For These Concerns: Wrinkles, fine lines, dryness, dehydration, sun damage, and pollution damage.
How Often Can You Use It: You can use it both morning and night.
What are Lipids?
Lipids are the skin’s natural fats. They are essential components of the skin and play a vital role in supporting the strength of the skin’s shielding barrier, which holds moisture, protects the skin from damage and keeps dirt and impurities away. They also aid the skin’s natural repairing process. Skin care formulations may contain concentrations of up to 5 percent lipids, but the majority of products have a lipid content of 0.1 to 1 percent because lipids are expensive ingredients. Lipid is primarily used in skincare products, eye and face makeup, hair care products, and shaving preparations.
The Benefits of Lipids
Healthy, youthful skin has plenty of these naturally occurring lipids. As we age, lipid production declines, and this can result in rough surface texture, uncomfortable tightness, dullness, and loss of facial fullness. A compromised skin barrier is also more prone to irritation and water loss. This is why it’s important to counter the effects of lipid loss with a topical treatment but not just any topical treatment.
Studies have shown that the most effective topical products for our skin are the ones with a lipid composition almost identical to our skin’s lipid composition: 1:2:1 ratio of ceramides, cholesterol, and fatty acids. This optimal ratio has been shown to significantly improve the appearance aging skin, helping to repair the skin’s barrier.
To better understand the functions of lipids as an ingredient in skincare products, it is first important to explain the natural function of lipids in our skin. You’ll find lipids as a natural component of the stratum corneum, the skin’s outermost layer. The stratum corneum is often referred to as the skin’s natural barrier, which is also comprised of corneocytes, ceramides, and free fatty acids. Ceramides represent about 50 percent of the skin’s lipid layer, cholesterol about 25 percent, and other fatty acids making up another 10 to 15 percent. A strong, intact barrier is important to keep moisture in and keep things like allergens, bacteria, and irritants out. When the barrier is weakened, these intruders can pass through the top layer of skin, causing damage that ultimately leads to common skin conditions such as acne, rashes, sensitive skin, and even signs of aging.
Since the skin’s natural barrier consists of lipids, this ingredient helps maintain proper barrier functioning by retaining moisture levels and regulating cell activity. It works to strengthen the outer structure of the skin and protect it from dehydration. lipids also function to repair skin that has been stripped of its natural lipids by things like exfoliating or applying an aggressive anti-aging treatment.
Due to its ability to strengthen and repair the skin’s natural barrier, those with delicate, sensitive, and dry skin types will likely benefit most from lipid-containing products. Furthermore, since cholesterol levels in the stratum corneum decrease with age (approximately 40 percent by age 40), using lipid-containing products on aged skin could be very beneficial.
Another function of lipids is to act as an emulsifier by keeping the water and oil parts of an emulsion from separating, generally forming w/o (water-in-oil) emulsions. According to FEMA, when water and oil are mixed and vigorously shaken, a dispersion of oil droplets in water – and vice versa – is formed. When shaking stops, however, the two phases start to separate. To address this problem, an emulsifier like cholesterol can be added to the system. Cholesterol forms a monomolecular layer around the emulsion droplet, which helps the droplets remain dispersed and produces a stable emulsion. It’s important to note that topically applied lipids will not have an impact on blood cholesterol.
The safety of lipids in cosmetics and personal care products has been assessed by the Cosmetic Ingredient Review (CIR) Expert Panel. The CIR Expert Panel evaluated the scientific data and concluded that lipids were safe as presently used in cosmetic products. In 2004, as part of the scheduled re-review of ingredients, the CIR Expert Panel considered available new data on this ingredient and reaffirmed the above conclusion.
The EU Cosmetics Directive permits lipids to be used in cosmetic products, so long as it complies with the animal-by-products regulations.
Clinical studies to evaluate the safety of topically applied lipids were conducted with products formulated with the ingredient. Most products were moisturizers containing 1.4 percent cholesterol. The cholesterol-containing products were minimal to mild primary and cumulative skin irritants but not sensitizers or photosensitizers.