Glycerin is one of the most common ingredients in the world. Industry loves this sticky, thick liquid because it is colorless, odorless and above all …. SWEET.
Hence its wide and varied use in processed foods, personal care products, and medicines. In fact, there is almost no industry where you won’t find it – particularly the plant-based version known as vegetable glycerin or glycerine as some people spell it.
It’s even one of the main ingredients in vaping liquid.
What is Glycerin?
According to the PubChem database, glycerin “is a trihydroxy sugar alcohol that is an intermediate in carbohydrate and lipid metabolism. (1)
Wow, what a mouthful, eh? Let’s unpack this.
So, first and foremost, glycerin is a sugar alcohol.
You are probably already familiar with sugar alcohols like xylitol, mannitol, sorbitol, and erythritol (Swerve).
Well, glycerin goes by another name which fits right in semantically speaking – glycerol.
Like all sugar alcohols, glycerol is sweet without containing sugar. This is why it was named “glyc,” which is the Greek root for sweet.
Chemist Carl Scheele discovered glycerol in 1779, and not long after, scientists learned of its indispensable role in human metabolism.
What makes this chemical so special? It is a naturally occurring molecule in all plant and animal fats! They owe their structure and integrity to glycerides, which form a glycerol-based backbone of sorts.
So glycerin/glycerol is 100% natural in it’s most primal form.
While industry can obtain glycerol from literally anywhere, companies prefer to use vegetable glycerin almost exclusively. More on this below.
You are probably most intimately familiar with glycerol’s role in your health per your triglyceride levels. Triglycerides are actually esters of glycerol. (2)
If you haven’t noticed already, glycerol from plants, aka vegetable glycerin, is an ingredient in a LOT of stuff!
From industrial uses to body care, medicines, and even low carb recipes and foods, you will find glycerin literally everywhere if you start to look for it.
This is because glycerin is really good at the things it does. It plays an important role in nearly every industry on the planet. (3)
Glycerin’s 10 most important superpowers are as follows.
Top 10 Benefits of Vegetable Glycerin
- Glycerin is an excellent emulsifier. This means that it helps join fats and other liquids together so they don’t separate.
- Its second important feature is as a solvent, meaning it helps one compound dissolve evenly into another. This is useful for the preparation of tinctures and distribution of food coloring.
- Due to its preservative qualities, companies use glycerine as a stabilizer and an auxiliary solvent in conjunction with water or alcohol.
- The pharmaceutical industry uses glycerol to extract and prevent inert materials from precipitating (coming out of solution to form a solid) when in storage. In foods, this property works well as a carrier for extracts and flavoring agents.
- When dried, glycerin has a plastic quality that is beneficial to coat tablets, beads and granules.
- Dried glycerol serves as an excellent reducing agent to decrease the particle size of a drug powder.
- Glycerin’s humectant and emollient properties are beneficial for drawing moisture out of one substance into another. This makes it useful as a pharmaceutical ingredient to prevent the drying out of preparations, particularly ointments and creams.
- In the food industry, glycerol is an important moistening and sweetening agent for baked goods.
- Food companies add it to candies and icings to prevent crystallization.
- Glycerol adds smoothness and thickness to any product that contains it. For this reason, glycerin is an ubiquitous ingredient in toothpaste, including many natural and organic brands.
Glycerine at Home
Glycerin is an important ingredient in homemade products and foods as well.
Because it is a humectant (helps preserve and slow the loss of moisture), glycerol is indispensable in DIY skin care products including soaps, moisturizers, lotions, masks, and more!
Since it is sweet and also a solvent, it is often used to make herbal tinctures. Alcohol tinctures are not always well liked by kids and some parents shy away from giving alcohol of any kind to small kids, so glycerin-based tinctures are popular for two reasons. It has a naturally sweet taste without any sugar or alcohol.
Since glycerin contains no calories or sugars, it is also sometimes used in sugar free, low carb, and other foods made at home for those on special diets.
Glycerin For Skin
Glycerin has many well researched, beneficial uses, especially for skin conditions. It is often part of treatments for dermatitis, and other skin issues. It also helps promote wound healing, so it is sometimes used in salves and other skin balms. (4, 5)
Note that since glycerol draws moisture from wherever it can get it. In humid environments, it will do it from the air, but in dry environments, when applied to the skin it will draw moisture up from the deeper layers. This can dry out the dermis and is one reason it is rarely used alone.
While glycerol containing skin products are not dangerous and may even be beneficial, glycerin toothpaste and other oral care products should be avoided. This includes organic brands of toothpaste, mouthwash and dental floss.
The problem occurs due to an inherent stickiness which encourages small amounts to remain on the teeth after cleaning. This inhibits the mineral rich saliva from contacting the entire surface of the teeth which can inhibit remineralization.
In short, toothpastes containing glycerin/glycerol may encourage the formation of cavities! This goes for homemade toothpaste too!
How is Vegetable Glycerin Made?
There are a number of ways to make glycerin. This is where the rubber meets the road with regard to its safety or toxicity when ingested.
Since it naturally occurs in all plant and animal fats, creating pure glycerin simply involves separating it out from the rest of the fats and compounds. So how does industy do that? And can you do that at home yourself?
As alluded to above, industry almost exclusively uses vegetable glycerin. This is because the process is most cost effective when using plants.
Plant-based glycerin is mostly a by-product of soap manufacturing. This process involves heating vegetable oil with a strong alkali such as lye (sodium hydroxide).
After that, some straining, separating, and concentrating creates a pure end product. There are several excellent online tutorials if you are so inclined to try it at home. (6,7)
Another way manufacturers make it is by heating coconut, soy, or palm oil under pressure with water so that the glycerin splits off into the water. Subsequent distillation then isolates the glycerin. (8)
So, we see that glycerin and mankind have worked together for a long time. As long as soap-making has been around, so has glycerin! It is also a by-product of candle making and the creation of biodiesel.
Unfortunately, natural processes are not the only way to make glycerin!
Synthetic Glycerin Dangers
Synthetic glycerin is very commonly used in industry nowadays.
It is a complex process that may begin with substances such as allyl chloride, acrolein, propylene oxide, polyalcohols, fats, or epichlorohydrin. Some of these chemicals are quite dangerous.
Allyl chloride, for example, causes toxic polyneuropathy (multiple nerve damage) with prolonged exposure.
One glycerin-synthesizing method involves oxidation of allyl chloride with hypochlorite to produce dichlorohydrin, which it converts to epichlorohydrin. The process subsequently hydrolyzes the epichlorohydrin to yield a glycerin solution.
Distillation then separates the water and glycerin with further refining to remove color and odor.
Another way to synthetically create glycerol is to oxygenate propene to acrolein, reduce it to yield allyl alcohol, and then epoxidate it with hydrogen peroxide. That creates glycidol, which industry hydrolyzes to produce glycerin. (9)
Sound complicated? It is!
It is primarily from these artificial glycerols that the potential for toxic residues and health dangers occurs.
Finding the Best Vegetable Glycerin
Glycerin is one of those substances that can be safe when of high quality and unsafe when of low quality.
Obviously, the high quality glycerin is the only kind you want to ever ingest or put on your skin (never your teeth!).
First and foremost, if you purchase glycerin, make sure it is FOOD grade or, even better, PHARMACEUTICAL grade (even higher/purer than food grade). This brand is ideal.
Second, go for either certified organic brands or those that utilize cleaner sources, such as palm or coconut oil.
The biggest issue with vegetable glycerin is what plant did the glycerol come from?
The “vegetable” in vegetable glycerin means everything from palm and coconut to corn and soy. So your glycerol may be derived from GM, pesticide laced corn and soy or it may come from relatively clean palm and coconut.
You never know UNLESS you ask.
Many companies selling glycerin, even relatively good companies that I contacted, are selling unsafe glycerol from GMO soy or other such industrialized crops!
Also note, some sources of glycerol are synthetic and the process used to make it involves all sorts of not so natural looking chemicals and processes as described above. Stay away from artificially synthesized glycerol with the potential for toxic residues.
Have you used glycerin in cooking or making homemade body care products? If so, have you found a good quality source you can share?
(1) PubChem Database
(2, 3) The Future of Glycerol
(4) Double Blind Study on the Effects of Glycerin and Urea on dry, eczematous skin
(5) Glycerin-Based Hydrogel for Infection Control
(6) Old School Beauty Basics: How to Make Glycerin
(7) How to Make Glycerin from Vegetable Oil
(8, 9) Naturally Derived Vegetable Glycerin
Where are your sources for your statements regarding glycerine in toothpaste and it coating not easily rinsed off?
You should ALWAYS list the sources where you get your information if you want to be seen as legitimate and not just spouting rumor.
I saw another comment regarding this, but I saw no answer.
Please respond with links to the sources that say glycerin is not healthy for toothpaste
A biological dentist told me this …. he said NEVER use anything in the mouth with glycerin as it inhibits demineralization.
Another oral health expert. “Watch out for products with alcohol, foaming agents like SLS, Saccharine, fluoride, glycerin, hydrated silica, artificial flavors, sweeteners, colors, even tiny plastic beads (ugg). Any ingredient that doesn’t have an easy to understand helpful reason to be in an oral hygiene product very well may take away from our ability to optimize the health of our mouth and should be avoided.” Will Revak, founder of Orawellness
Can you provide any studies that prove glycerin to be bad for your teeth? I keep reading articles like this that claim it but I have yet to see any proof.
Good info and would like to share to Facebook !
I understand that soap breaks down fats, and pulls viruses apart, but what about glycerin? I have a glycerin bar (not soap with glycerin, just the glycerin), and I want to know whether it’s as effective as soap at cleansing your hands of germs.
Jessie, this is very interesting question you asked. Shame they haven’t came back to check people’s comments on this post. I would like to know the answer to your question too. Also how does glycerin keep together as a solid block, how does it become a glycerin bar? Isn’t it soap then?
This is really helpful thank you! I’ve been DIY-ing household products and personal care products for about a year now and always wondered exactly what the vege glycerin was for. I’m in the UK and buy from a local source who say theirs is Pharma grade derived from sustainable Rapeseed. I’ve felt pretty comfortable buying from them and one litre has lasted me more than a year!! Is there anything else you would recommend I ask the company?
Thanks Sarah! Wish it would just link me to amazon.com and then I could easily check the availability on amazon.ca. Oh well, my sister lives in the states so can have her check for me. Thank-you for reminding us that we can take more of an active role in evaluating products and also thanks so much for the helpful guidelines you provide so we can actually do this!
Hi Sarah, Living in Canada the product link that you often provide sends me to amazon.ca and often I’m sure that the product that shows up is not the exact product being recommended but something similar or amazon.ca will tell me this product is not available. Since the name of the product is not shared there’s no way I can even find out which product you’re actually recommending. I simply can’t risk purchasing the amazon.ca product if I don’t know for 100% sure it’s the one you’re referring to. Is there a way you can let us Canadians in on the name/brand of the recommended product? I’ve been meaning to mention this for a long time. Are there other Canadians running into this??
Sarah Pope MGA
Mentioning brands within an article makes maintenance a nightmare over time … I keep the amazon links updated and check them all every few months, but updating all the written articles where brands are mentioned when things change and I have to recommend something else would be far too much unfortunately. I learned the hard way early in my blogging career to avoid this as much as possible … loooong story.
Before I include a link, I always mention how to evaluate a product so that someone doesn’t have to buy the product I recommend if they find something else that is cheaper or as good quality in their area. In this article, glycerin is recommended to be organic and pharma or food grade and derived from a clean source like coconut or palm oil (as opposed to soy), so if the product you see on amazon.ca has those characteristics, it’s fine even if it’s not the brand I recommend. I am not married to particular brands … I am looking for a set of product characteristics because brands change/companies get bought out and product quality can fluctuate over time – for better or for worse! Characteristics of what to look for don’t change. Hope that makes sense.
I sure can share – Wilderness Family Naturals – I use their food grade glycerine – it contains no stabilizers, preservatives or other added ingredients. Coconut derived – which I love because I cannot do soy. They have great prices too!