How Do You Use Glycerin?
A Liquid Ingredient Found on Skin Care and Food Labels
Medically reviewed by Elizabeth Barnes, RDN
Glycerin, also called glycerol and glycerine, is a sugar alcohol that occurs in nature and is also produced synthetically. It is a thick and sticky nontoxic liquid that has no color or odor.
Glycerin has many uses in cosmetics, drugs, and household products. It is used as a moisturizer, a preservative, and a food sweetener. It has value in items that include lotions, soap, and food. It is also used in diverse products, including antifreeze, cement, textiles, and waxes.
This article describes the makeup and many uses of glycerin.
Glycerin Uses: What's It Made Of?
Glycerin is made of three carbon atoms, eight hydrogen atoms, and three oxygen atoms in the formula of C3H8O3. This compound is a carbohydrate called a sugar alcohol, or polyol.
Glycerin liquid occurs naturally from the fermentation of certain foods like honey, vinegar, and beer. However, most of the glycerin used is obtained from the following sources:
Plant-based sources: Natural glycerin is obtained from coconut, palm, and soybean oils and fats.
Animal-based sources: Glycerin is obtained when tallow (beef or mutton fat) is combined with water and heat and then chilled.
Synthetic: Synthetic glycerin can be petroleum-based and produced from propylene. It is produced from cane or corn syrup sugar.
Glycerin has the following uses:
Cosmetics
Glycerin is good for your skin. Its characteristics as a humectant (a substance that reduces the loss of moisture), solvent, and lubricant are valuable to skin care products.
The primary benefit of using glycerin on dry skin is its ability to prevent water from evaporating. It can keep your skin hydrated longer than other moisturizing products. Research indicates that glycerin has strong moisturizing factors and is a powerful and effective humectant.
Foods and Beverages
Glycerin has multiple uses in foods. It is most often found in processed, packaged, and frozen foods used in the following ways:
Emulsifier (stabilizes ingredients and prevents them from separating)
Sugar substitute (sweetener)
Humectant (helps to preserve foods by preventing drying)
Solvent for food coloring and flavors
Softening agent in candy, cakes, and meat/cheese casings
Personal Care
Glycerin has value as a humectant, solvent, lubricant, and sorbitol (another sugar alcohol used as a sweetener) replacement in personal care products. It is a common ingredient in the following products:
Toothpaste
Mouthwash
Skin care products
Deodorants
Soaps
Baby care products
Pharmaceutical
Glycerin is used as a key ingredient in the manufacture of the following pharmaceutical products:
Suppositories (medicine contained in a small solid piece of glycerin)
Gel capsules
Some medications
Some types of anesthetics
Household, Industrial, and Institutional
Glycerin is widely used in household, industrial, and institutional products, including the following applications:
Deicing or anti-icing fluids
Antifreeze
Lubricating, sizing, and softening of yarn and fabric
Paper manufacturing
Major raw material in the production of flexible foams
Surface coatings and paints
Candle and soap manufacturing
Glues
Embalming fluids used by morticians
Learn More: Moisturizer Ingredients: Understanding the Label
Forms of Glycerin
Glycerin may be included on the label of many over-the-counter consumer products as it is used in the manufacturing process. Glycerin is used in the following forms where it may be indicated as a major component of the product and considered an active ingredient:
Liquid: Liquid glycerin is used as an ingredient in cosmetics, foods, and medications. Pure liquid glycerin can also be applied to your face as a moisturizer.
Creams and lotions: Glycerin may be used in skin care products for its moisturizing effects.
Soap: Soaps made from glycerin help skin retain moisture. A key characteristic of these soaps is that they are translucent. This is due to the addition of alcohol, which prevents the soap from crystallizing.
Eye drops: Glycerin is used in lubricant eye drops and artificial tears.
Suppositories: A glycerin rectal suppository may be used for the occasional relief of constipation. They are available over the counter for children and adults, but it is best to consult a healthcare provider if a child has constipation.
How to Identify the Source of Your Glycerin
Glycerin can be obtained from two different kinds of sources. Natural and synthetic glycerin have the same chemical composition. However, unless "vegetable," "animal," or "synthetic" glycerin is indicated, the only way to know the source of glycerin is to check with the manufacturer of the product you're using.
When Would Glycerin Cause Side Effects?
The safety of glycerin is well-documented. It is considered a "generally recognized as safe" (GRAS) food substance by the Food and Drug Administration (FDA).
However, it can cause some side effects when consumed in amounts that are not found in individual foods or a typical diet. With excessive consumption, glycerin can cause a laxative effect with the following symptoms:
Though rare, glycerin can also cause side effects when applied topically. In these cases, it is likely to cause the following symptoms of contact dermatitis (a skin reaction from direct exposure to a specific chemical substance):
General skin irritation
Rash that lasts for days or weeks
Angioedema (swelling in the deep layers of your skin)
Glycerin may also cause burning and stinging if it gets in the eye.
Learn More: Causes of Dry, Itchy, and Flaky Skin
How to Safely Apply Glycerin for Face Benefits
Glycerin is a key ingredient in many cosmetics, and you can safely apply the glycerin alone to your face. Glycerin is readily available for purchase in drugstores and online. Consult with your healthcare provider to determine the best formulation to use if you are unsure which product to try.
Before using any new product on your face, you may wish to perform patch test. Apply a small amount to a small area of skin (such as on the underside of your arm) twice a day and check it in over the course of several days for any sign of irritation, such as redness or discoloration, swelling, or itchiness.
Before using, read the package instructions. Many products only say to apply it to the skin, which you might do with a cotton pad or tissue. Rinsing the skin first may help keep moisture in. You may wish to dilute the glycerin with tap water to thin it.
Summary
Glycerin is a compound liquid widely used in the cosmetics, pharmaceutical, and food industries. Glycerin acts to retain moisture, to sweeten foods without adding sugar, and to preserve food. It also serves as a binding agent, laxative, and antifreeze. This nontoxic compound rarely causes problems when consumed in foods or used on your skin.
While this substance is commonly used, excess use can lead to adverse effects. Consult your healthcare provider if you notice redness, itching, or other skin problems when using this product. A reaction to overconsumption of glycerin orally may cause nausea and stomach problems.
