What Is Vegetable Glycerin? Uses, Benefits and Side Effects

Glycerin is a sugar alcohol derived from animal products, plants or petroleum.

Vegetable glycerin is the variant made from plant oils. It is said to have been accidentally discovered more than two centuries ago by heating a mixture of olive oil and lead monoxide.

But it only became economically and industrially significant in the late 1800s when it was first used to make dynamite.

Vegetable glycerin is made by heating triglyceride-rich vegetable fats — such as palm, soy and coconut oils — under pressure or together with a strong alkali, such as lye.

This causes the glycerin to split away from the fatty acids and mix together with water, forming an odorless, sweet-tasting, syrup-like liquid.

Summary

Vegetable glycerin is a slightly sweet, syrupy liquid made by heating vegetable fats under pressure or together with a strong alkali.

Vegetable glycerin is widely used in the food, cosmetics and pharmaceutical industries.

For instance, it is often added to foods to help oil and water-based ingredients mix, sweetening or moistening the final product.

It can be also used to prevent ice crystals from forming in frozen foods, such as low-fat frozen yogurt, ice cream and other desserts.

Glycerin is a common ingredient in pharmaceutical drugs, including heart medication, suppositories, cough remedies and anesthetics.

Additionally, you can find vegetable glycerin in toothpaste, as it helps prevent the toothpaste from drying out or hardening in the tube.

What’s more, it’s commonly added to soaps, candles, lotions, deodorants and makeup.

Summary

Vegetable glycerin has several uses. The most popular are cosmetics, pharmaceutical drugs and food products.

Vegetable glycerin is touted as a product with numerous health benefits.

However, only a few benefits are supported by science — and the related studies tend to be few and small. Keep in mind that more studies are needed on its health benefits.

The following benefits have the most research behind them.

May moisturize skin

Vegetable glycerin is a popular skincare treatment because of its moisturizing power.

Research shows that applying glycerin to your skin may gradually improve its smoothness and suppleness. In fact, using creams containing glycerin may increase skin hydration in as few as 10 days (1, 2).

In one study, a cream made from glycerin was more effective than those made from silicone oil or hyaluronic acid at hydrating skin and preventing loss of moisture (3).

In another study, adding glycerin to a warm water bath was more effective at improving skin moisture levels and protecting against skin irritation than a warm water bath alone (4).

May promote skin health

Vegetable glycerin may lead to better skin health by helping soothe skin irritation, protect against infection and promote wound healing.

Studies show that applying glycerin-containing products may protect your skin against irritants and microbes, as well as soothe inflamed or wounded skin (5, 6).

Moreover, vegetable glycerin may act as a barrier to safeguard your skin from the elements, including wind and cold (5).

Another study reports that vegetable glycerin may be more effective than a placebo at reducing sensations of smarting in people with eczema. However, it appears to have no effect on stinging, itching, drying or irritation (7).

May reduce constipation

Vegetable glycerin may provide some relief from constipation.

That’s because it can draw water into your gut. This has a laxative effect, which helps digested food move through your gut more smoothly.

For this reason, glycerin is often used as a suppository.

In one study, glycerin suppositories were significantly more effective at reducing constipation caused by pain-killing medication than other types of laxatives (8).

In another, a glycerin enema was 16.5% more effective at relieving constipation than a liquid soap enema (9).

May boost hydration and athletic performance

Glycerin may also boost hydration, which can improve your athletic performance.

Dehydration can greatly impair athletic performance, especially when sweat loss exceeds 2% of your body weight (10).

A good strategy to avoid dehydration is to drink enough liquids both before and during exercise. However, it can be impractical to drink during certain types of physical activity. In such a case, drinking plenty beforehand is key.

The problem with drinking large amounts in a short timespan is that a sizable portion of the fluid is generally lost through urine in the following hour.

However, in one meta-analysis, adding 1.1g/kg of body weight, or .5g/lb of body weight, to water drunk before exercise increased fluid retention by 50% compared to water alone. Glycerin may also lead to small improvements in athletic performance (11).

In another study, a glycerin drink was also more effective than water or a sports drink at improving hydration in athletes who lost significant amounts of water through sweating during exercise (12).

Summary

Vegetable glycerin may act as a moisturizer, reduce skin irritation, protect against infection and boost wound healing. It may also help relieve constipation and promote hydration and physical performance. That said, more studies are needed.

Vegetable glycerin is generally considered safe.

That said, you may experience an allergic reaction if vegetable glycerin is applied directly to your skin — so it’s best to start with a small amount to see how your skin reacts.

When ingested, vegetable glycerin may cause headaches, dizziness, nausea, vomiting and excessive thirst in some people (13).

Since glycerin is a form of sugar alcohol that your body cannot fully absorb, consuming too much — either alone or through foods — may also lead to gas and diarrhea.

Summary

Vegetable glycerin is generally considered safe. However, there is a possibility of allergic reaction, headaches, nausea, thirst and stomach upset in some people.

Vegetable glycerin is a clear, odorless and sweet-tasting liquid derived from vegetable fats.

It is added to food, cosmetics and pharmaceuticals and may offer health benefits, such as moisturized and resilient skin, relief from constipation, improved hydration and better physical performance.

If you’d like to give vegetable glycerin a try, start with a small amount to see how you react.