Moisturizing (humectant),Soothing,Emollient,Fragrance,Denaturant,Solvent,Viscosity controlling
Botanical, Synthetic, Animal
Glycerin is one of the oldest and most used skincare ingredients known to man, and rightly so. This sweet-tasting, clear, syrupy liquid acts as a humectant moisturizing ingredient and can be found in most skincare products on the market. It is a natural part of our body and skin and serves many purposes.
For use in skincare, glycerin is often obtained from plant-based oils. This ingredient is sometimes referred to as ‘vegetable glycerin’. It is important to note, however, that no matter if it was obtained from animal fat or chemically from sugars, it is still exactly the same molecule, with exactly the same properties.
The benefits of glycerin in skincare are varied, and quite honestly, pretty incredible for such a simple, accessible, and cheap ingredient. So incredible, in fact, that it happens to be one of the two most popular humectant ingredients in the world, alongside the famous hyaluronic acid.
Glycerin has been shown to help reduce trans-dermal water loss and improve the properties of the skin’s lipid barrier. In other words, after application, this superstar ingredient gets absorbed into the entire stratum corneum (the topmost skin layer), where it goes on to improve the skin’s water-holding capacity and leaves the skin well moisturized at the surface.
Glycerin also has soothing and anti-irritant properties, and regular use of the ingredient can result in reduced skin roughness and improvement in the overall feeling of the skin.
Glycerin is able to perform these effects at almost any concentration. Concentrations ranging from 5% to 50% have all been proven in studies to be effective at improving hydration.
Pure 100% glycerin, however, actually has a dehydrating effect on the skin. A study showed that the ingredient in its pure form must be accompanied by a least a bit of water in order for the skin to reap its humectant benefits.
Glycerin’s powerful humectant moisturizing effects make it a key ingredient in the treatment of various dry skin conditions such as eczema and psoriasis. It has been shown that the ingredient can become even more powerful when formulated with occlusive ingredients such as Vaseline, liquid paraffin, or jojoba oils. This is because while the glycerin brings water to the stratum corneum, the occlusive ingredient prevents it from evaporating from the skin, resulting in overall better moisturization.
Its effects on scars, skin discoloration, or acne, however, are yet to be known.
Glycerin is very safe to use (even during pregnancy and breastfeeding), and seldom causes any side effects or allergic reactions.
Skincare enthusiasts are often curious about how glycerin compares to other ingredients. Some of these inngredients are propylene glycol and, of course, hyaluronic acid. The research may provide some answers.
Propylene glycol is another popular humectant moisturizing ingredient. According to one research, it has more-or-less the same effects on the skin as glycerin, even though it has one less alcoholic group.
There was another study that compared the moisturizing effects of glycerin (at concentrations of 5% and 10%) to various types and concentrations of hyaluronic acid in the same emulsion cream base. The results were incredible. They found that glycerin actually outperformed hyaluronic acid in most tests, even though the moisturizing effects of all the tested formulas were good.
While glycerin was able to immediately moisturize the skin, hyaluronic acid only showed equally good results 24 hours after application.