An In-Depth Look at Glycerin: What is it and What Does it Do for Skin?

Reference Lab

JUN 13, 2023

Skin care can become overwhelming with a variety of ingredients that promise to deliver a range of benefits. We’re here to help you cut through the clutter and determine which ingredients are worth the hype and which are best for your skin health. One of the most common ingredients in the skin health industry is glycerin, which is frequently used in moisturizers and cleanser products. But what exactly is glycerin, and what does it do for the skin? In this blog, we'll take an in-depth look at the benefits of glycerin, exploring its properties and potential drawbacks.

Glycerin, also called glycerol, is a colorless, odorless, and viscous liquid used in a variety of industries, but is especially common in topical skin care products. It can be extracted and produced in several different ways; from fermenting sugars, like glucose, to extraction from plants such as soybeans, coconut, palm, and rapeseed. The most common way that glycerin is extracted from the oils of these plants is through a process called hydrolysis, where a strong alkali breaks down the oils into their individual fatty acids before being heated and treated with water to separate the pure glycerin from the fatty acids.

Glycerol is most frequently used in products that aid in skin’s hydration because of its nature as a humectant, meaning it's able to attract and retain moisture when absorbed into the skin.¹ Glycerin is also a natural emollient, which helps soften and smooth the surface of the skin by trapping moisture in the skin, and by filling in gaps between skin cells.² Through both of these properties combined, glycerin helps to soothe dry skin or irritated skin by acting as an anti-inflammatory agent.³ Glycerin is a trihydroxy sugar alcohol which is a type of organic compound that is derived from sugar sources. Glycerin is found in plant and animal sources bound up in compounds known as triglycerides, which combine glycerin with three fatty acids. This is why a major part of extracting glycerin involves breaking up the triglycerides in plant oils and separating the glycerin from the fatty acids. The greatest sources of these plant oils are Indonesia, Malaysia, and the Netherlands which accounted for more than half of the world’s total glycerin exports in 2021.⁴ Glycerin has many uses across a variety of industries and products, such as in food, pharmaceuticals, medicine, and also skin care. In the food industry, glycerin is predominantly used to help food retain moisture, thicken liquids, add extra sweetness, and as a preservative. Glycerin is also useful in the medical industry for its wound healing and anti-microbial properties, enabling it to help speed up recovery and reduce the risk of infection. Glycerin specifically helps with wound healing because of its nature as a humectant, meaning it attracts and retains moisture at the site of the wound. This moist environment can help mitigate inflammation and encourage the growth of new skin cells. Glycerin is also a bacteriostatic, giving it the ability to restrain the development or reproduction of bacteria, helping to prevent inflammation due to infection.⁵

The medicinal properties of glycerin also apply to its use in skin care, with a focus on its hydrating and emolliating properties. Since glycerin is a humectant, which aids in maintaining the moisture balance of the skin, it is commonly used in body lotion products or moisturizers and other products that are meant to be hydrating. It’s also commonly included in skin care products to help mitigate any potential skin irritation. By creating a protective barrier on the surface of skin, emollients make well hydrated and healthy skin more supple and smooth. ⁶ Finally, glycerin has been found to be relatively inert, non-irritating and non-comedogenic, allowing it to be included in a variety of formulations with a low risk of ingredient conflicts and adverse reactions.⁷ Glycerin holds a number of benefits for skin. The most notable of glycerin’s benefits is its hydrating property. Hydration is a crucial component of skin health, as it helps bolster the skin barrier and prevent the development of fine lines and wrinkles. Properly moisturized, healthy skin has also been shown to display improved elasticity and firmness by prompting collagen synthesis, which in turn boosts the health of the skin barrier and provides a more youthful appearance.⁸ Glycerin is considered safe for those with sensitive skin, as it is non-toxic and non-irritating, with the Environmental Working Group (EWG) rating glycerin a score of 1/10, indicating very safe usage.⁹ Finally, since glycerin is non-comedogenic, it won’t add any extra stress or oils to acne prone skin.⁷ The easiest way to incorporate glycerin into your facial skin care routine is to use a moisturizer or serum that contains glycerin. If you partake in DIY skin care, you may also mix glycerin with water or aloe vera gel in a 1:4 ratio and then apply the mixture to the skin.¹⁰ You can also add a few drops of glycerin to moisturizers or serums that you already have on hand to improve their hydrating properties.

When applying glycerin to your face in any form, it’s best practice to first wash your face with warm water to open up the pores and bring some moisture to your skin. At this point, you can apply glycerin to your skin to help soothe and hydrate the area.³ Don’t forget to use sunscreen as a final layer in the daytime to protect the skin against UV damage, which can help maintain skin elasticity and firmness. As with any new ingredient, it's recommended that you test glycerin on a patch of skin and wait 24 hours before fully introducing it into your skin care regime. Glycerin on the rest of the body can be used in much the same way as on the face to improve the hydration and texture of the skin. You can first begin by taking a warm shower or bath to open up the pores and cleanse the skin. Then you can pat the skin dry, leaving it damp but not wet, before applying the peptide moisturizer or peptide eye cream to the desired area. By leaving your skin damp when applying glycerin, you can give it the best opportunity to lock moisture into the skin. For best results, glycerin can be used daily, paying particular attention to areas that require extra hydration, such as the elbows, knees, and heels. Again, consider applying sunscreen as the final layer during your daytime skin care routine to protect the skin against UV damage. Due to its inert, non-comedogenic, and hydrating properties, OneSkin utilizes glycerin as a core humectant in their products. Like all ingredients that OneSkin uses, the glycerin contained in OneSkin’s formulations is sustainably sourced, data-validated, and of premium quality. In particular, the glycerin in PREP is sourced from Amazon Oils, a vendor located in Brazil amongst the largest fluvial-maritime archipelago in the world, with an enviable diversity of plant species. These wild species grow naturally in the rainforest and are processed sustainably without pesticides or fertilizers, then cold extracted with no added preservatives or additives.

• Glycerin is commonly used across the skin care, food, and medical industry for its inert, hydrating, and safe properties.
• Glycerin is a humectant, meaning it's able to attract and retain moisture when absorbed into the skin.
• As a natural emollient, glycerin helps to soften and smooth the surface of the skin.
• Glycerin helps to soothe dry skin or irritated skin by acting as an anti-inflammatory agent.
• The moist environment created by glycerin can reduce inflammation and encourage cell proliferation.
• Glycerin is bacteriostatic, which aids in preventing inflammation due to infection.
• Glycerin has been found to be non-irritating, non-toxic, and non-comedogenic.
• Glycerin is safe for use on oily skin or acne-prone skin.

By Felix Tajanko:
Felix is studying Bioengineering at the University of California - San Diego and is passionate about scientific writing as well as the research of hormones and microhemodynamics.

Sources:

1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5560567/
2. https://pubmed.ncbi.nlm.nih.gov/18025807/
3. https://pubmed.ncbi.nlm.nih.gov/26370610/
4. https://oec.world/en/profile/hs/glycerol
5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3839013/
6. https://www.aciscience.org/docs/Glycerine_-_an_overview.pdf
7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4025519/
8. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6559254/
9. https://www.ewg.org/skindeep/ingredients/702620-GLYCERIN/
10. https://www.themakeyourownzone.com/make-your-own-glycerin-skin-moisturizer/