Sep 04, 2023

What are the benefits and side effects of vegetable glycerin?

Vegetable glycerin is a clear, odorless liquid that has a sweet taste. It has a wide variety of applications and manufacturers regularly use it in cosmetic, skincare, and pharmaceutical products.

Glycerin can come from animal sources, but vegetable glycerin is plant-based and typically comes from soy, palm, and coconut oils, meaning it is suitable for vegans.

Vegetable glycerin is a common ingredient in many products due to its sweet flavor and moisturizing properties. It may also possess health benefits, with some research suggesting it can improve skin and digestive health. However, other research notes that it may cause an adverse reaction in some people.

In this article, we will discuss the various uses and potential benefits of taking vegetable glycerin, as well as the potential side effects.

Glycerin, also known as glycerol or glycerine, is a naturally occurring sugar alcohol compound. Sources of glycerin can include animal and plant fats. Manufacturers can also synthetically produce glycerol. For vegetable glycerin, common sources include triglyceride-rich vegetable fats, such as soy, coconut, and palm oils.

Most vegetable glycerin comes as a byproduct of industrial chemical reactions. For example, vegetable oils can either undergo a process known as saponification or transesterification to produce vegetable glycerin. These are common steps in the soap and biodiesel manufacturing processes. They involve heating the oils under pressure or together with either an alkaline or alcohol solution.

This process causes glycerin to split away from the fatty acids. Manufacturers can then extract the oderless, sweet tasting, syrup-like liquid known as glycerin.

Glycerin has many uses in various industries. For example, glycerin is broadly used in a range of cosmetic products, such as skin care, hair care, and oral hygiene products. In 2014, the U.S. Food and Drug Administration's Voluntary Cosmetic Registration Program stated that glycerin was the third most commonly used ingredient in cosmetic products.

People can also use glycerin in food products. For example, glycerin can act as a preservative and sweetener in food and drinks. Additionally, manufacturers may also add glycerin as a humectant, meaning to help food retain moisture.

In the pharmaceutical industry, manufacturers use glycerin as a lubricant and humectant. They typically include glycerin in cough syrups, ointments, expectorants, anesthetics, and lozenges. Manufacturers may also include it in capsules for drugs.

While more research is necessary, the potential health benefits of vegetable glycerin may include:

As glycerin is a humectant, it can help skin retain moisture. Glycerin is able to diffuse into a layer of the skin known as the stratum corneum, making it an effective moisturizer. For this reason, many manufacturers add glycerin to topical products.

A 2017 study notes that glycerin is effective for alleviating skin dryness, while another 2017 study suggests that it can also help to improve the barrier function of the skin. Retaining moisture and maintaining skin barrier function are important for sustaining skin health.

While more research is necessary, a 2015 mouse study also suggests that glycerin may possess anti-irritant and anti-inflammatory properties.

As glycerin has a laxative effect, people can use it to relieve constipation. When a person administers glycerin rectally, it helps to lubricate the rectum and soften stools. It draws water towards the hardened stool and helps the bowel muscles to contract more effectively.

Although research is scarce, some evidence suggests that vegetable glycerin may have some benefits on athletic performance.

Fluid loss can have a detrimental impact on athletic performance, which is why maintaining hydration is important. People typically lose fluids through sweat or urination. When a person consumes glycerin, it can help enhance fluid retention and decrease the volume of urine.

One older study notes that consuming glycerin may help to improve athletic performance, but may cause an increase in body weight.

Other research notes that consuming creatine and glycerin may help endurance runners reduce strain on their cardiovascular system. However, this study also notes that it may increase body weight due to fluid retention. Another older, small study of nine athletes suggests that glycerin is more effective for rehydration than water, a sports drink, or saline. It found the best effects with a combination of IV fluids and oral glycerol. However, the study found that it did not significantly improve exercise performance.

While glycerin is generally safe and non-toxic, a person who consumes it orally may have some side effects. They can include:

Therefore, a person may wish to seek medical advice before using glycerin.

Vegetable glycerin also can rarely cause an allergic reaction. For example, a 2016 study found that a person who received an enema mixture containing glycerin developed a skin rash. In a severe case, an allergic reaction to glycerin could cause anaphylaxis.

Due to its consistency, some people might consider using glycerin as a vaginal lubricant. However, this can increase the risk of developing yeast infections. Therefore it is not advisable for people to use vegetable glycerin as a lubricant.

A person may want to consider conducting a patch test to ensure that their skin does not react negatively to a product containing glycerin, by applying a small amount first and waiting to see if their skin reacts.

Vegetable glycerin is a sweet, clear liquid that comes from vegetable oils. Glycerin can also come from animal sources, but vegetable glycerin is a vegan alternative. It is a common ingredient that manufacturers may add to cosmetic, food, and pharmaceutical products.

Due to its ability to retain moisture, glycerin may be beneficial for skin health, digestive health, and improving athletic performance. However, it can cause some gastrointestinal distress and some people may be allergic to glycerin. It may be advisable to speak with a doctor before using products containing glycerin.