The Myth That Glycerin Is Bad for Your Teeth--Debunked
Since you're here, you've likely heard that glycerin is a terrible, horrible, no good, very bad ingredient to have in toothpaste.
Many natural sources say that even though you're already likely avoiding fluoride and that awful SLS (Sodium Lauryl Sulfate--a foaming agent) in toothpaste, you'd better be avoiding glycerin too.
Ack! As if we don't have enough to be concerned about--now we need to worry about glycerin too?!
This sure is a hard pill (or blob of toothpaste) to swallow because glycerin is in most toothpastes--both conventional and natural. (Oh and if you're using toothpaste with fluoride in it, do not swallow any toothpaste and DO call Poison Control if you do--but I digress).
Welp, never fear. I'm going to break this down for you and present you with a pretty solid debunking of this whole glycerin toothpaste myth.
Figuring Out What's Healthy Is Hard
After awhile, all of this healthy living information gets really hard to wade through, doesn't it?
First, you hear that eggs are bad for you, then they're good.
You hear that you should avoid sugar, then you hear that erythritol is linked to heart disease, stevia is bad for your health, and even that xylitol might cause tumors....
It's enough to make you want to throw in the towel and eat a pint of ice cream and several Snickers Bars.
Well, hold on.
First of all, if you're going to grab something, may I encourage you to instead choose this Healthy Chocolate Ice Cream and these Sugar-free Snickers.
Second, you'll soon see that you probably don't need to toss your toothpaste.
What is Glycerin?
Also known as glycerol, glycerin is a natural compound derived from vegetable oils, animal fats, or petroleum through fermentation of yeasts, sugars, or starches. It's clear, colorless, and odorless, and is very very sweet.
A Swedish chemist, Karl Wilhelm Scheele, accidentally discovered glycerin in 1779 when heating a mixture of lead oxide and olive oil.
It can be used as a candida-safe sweetener, like in these Homemade Sugar-free Marshmallows, but is also used in personal care products, like this Homemade Foaming Soap. It is also used in glycerites (which are another type of sweetener) and as the base for alcohol-free "extracts" like this Alcohol-free Vanilla.
What Is Glycerin Made From?
The most common sources of glycerin are natural--coconut, soy, and palm.
In the 18th and 19th centuries, people often used candles and soaps containing animal fat to make glycerin.
These days, plant based oils are more commonly used for making glycerine.
Petroleum can also be used to make glycerin but that method of making glycerin wasn't discovered until 1948. It's more costly to make glycerin this way so it's not the source of most glycerin on the market.
If you're concerned about GMOs, simply choose organic or non-GMO glycerin to avoid such concerns.
When I Almost Tossed My Toothpaste aka Negative Claims About Glycerin
I believe it was in the book Cure Tooth Decay where I first read that glycerin is bad for your teeth. The author stated that glycerin coats tooth enamel and that it can take a lot of brushing to get that coating off.
Oh the panic I felt when I ran to the bathroom, pulled out our natural toothpaste, and read the word "GLYCERIN" right there, in black and white on the label.
Here I was trying to be oh so healthy by choosing a natural toothpaste, and now this?!
As time went on, I heard more and more people talking about this.
I found some toothpastes without glycerin, but then later really needed remineralizing toothpastes, and guess what--they pretty much ALL had glycerin in them, so I hesitatingly bought some and used then, thinking "Well, it can't be all that bad. Can it?"
Then recently, I started wondering again and started researching....and found some troubling information in the form of a sort of scary (to me) study.
That led to more research--which led to this post.
Did I Find the Study Proving Glycerin Is Bad for Your Teeth?
Most authors who claim that glycerin doesn't prevent remineralization state that they can't find a single study showing that glycerin is a problem.
That seemed to be the case, but one day, while reading through the comments of a post, I found it. Someone shared this study, saying that it showed that glycerin reduces the hardness of teeth."
And yes, it seemed to do just that.
The Study Details
In the study, a variety of substances (including plain glycerin) were applied to prepared (dead) tooth fragments, and left there for 8 hours. Then the fragments were submerged in artificial saliva for 16 hours.
Here is what the researchers concluded:
Glycerin also presented slight decreases in microhard-https://www.researchgate.net/publication/7500507_The_effect_of_10_carbamide_peroxide_carbopol_andor_glycerin_on_enamel_and_dentin_microhardness
ness for sound enamel and dentin, similar to the effect
of carbamide peroxide. It could act as an adsorbed layer
barrier to artificial saliva and to a remineralizing effect.
At first glance, this seems to be the death knell for glycerin-containing toothpaste.
Not. So. Fast.
Problems With the Study
First of all, the control was a 10% carbamide peroxide solution. In their words "it [carbamide peroxide] is accepted as safe and effective by the American Dental Association (ADA)”
What that means is that the control substance had already been determined to not damage teeth, and glycerin performed better than the control in most aspects of the study.
The Artificial Saliva Factor
Note that all of the substances they tested showed decreased microhardness, but we don’t much about their artificial saliva except other studies they referenced where they used it. How do we know their saliva wasn’t already decreasing the micro hardness of the teeth?
It would have been much better to have water or another substance (xylitol, erythritol, or sorbitol would have been good options) as another control. Or their artificial saliva alone would have been good to have as a control to know what that did to the teeth.
Also note that the solution was “supersaturated” with minerals. That means that the water had so many ions in it that nothing else could dissolve in it. Think about what happens if you dump a lot of salt into a small glass of water. At some point, you just can't dissolve any more salt into the water.
So, the artificial saliva was so saturated that the glycerin wasn’t able to dissolve and the minerals in the artificial saliva solution reach the tooth for remineralization. Nothing else could dissolve in the saliva solution--that really complicates things.
That's Not How Toothpaste Works
While this study is interesting, it's not how toothpaste works in the mouth.
Teeth don't sit in a solution of toothpaste and saliva. Your mouth continually produces saliva (ever notice how your mouth fills up when you're brushing?) Also, you rinse your mouth after you're done brushing, and again, the saliva in your mouth isn't supersaturated.
Who Started This Glycerin Myth Anyhow?
It seems the whole demonizing of glycerin thing started with Dr. Gerald Judd (Chemistry Ph.D.) who wrote a lot about dental health a number of years ago.
Judd seemed to be trying to figure out ways to keep teeth healthy and had some interesting views.
originally claimed that glycerin leaves a coating on the teeth that according to him “takes 27 washes to get it off”.
He also said that “teeth brushed with any toothpaste are coated with a film and cannot properly remineralize”.
Interestingly, he recommended brushing teeth with soap, (note that he stated that it only takes 2 rinses to remove soap from your teeth)--perhaps this is the first red flag since doesn't that mean that his recommended soap is sticking to teeth too?
Others claim that not only does glycerin inhibit tooth remineralization, but that it's a plaque magnet leading to the growth of bad bacteria, which can cause bad breath, gum disease, and even tooth decay. Yikes!
So I went on a hunt for another toothpaste and went on my way using another brand for awhile.
But the whole topic still bugged me from time to time, and at some point I decided to research it further.
Here's what I found.....
But is it bad for your teeth? Let's find out!
Other Dental Claims By the Same Doctor That Don't Make Sense
First of all, Dr. Judd didn't write mostly about glycerin.
In fact, he didn't write much about glycerin at all.
Most of what he wrote was about other tooth-related issues.
For some reason, however, this glycerin thing has gotten the most traction in the natural health arena,
Some of his other thoughts, well--
Just because someone makes incorrect (or even wacky) statements about other things doesn't make their other claims wrong, but it can be a cause for concern. Either the person doesn't know what he/she is talking about, doesn't research well, is a sensationalist, is crazy, or is lying.
Dr. Judd, while he does have a much stronger background in chemistry than I do with my college level chemistry course, said some things about teeth that don't make sense. You can find a short outline of some of his claims here, a letter to his followers here, and a full copy of his book, Good Teeth from Birth to Death here.
While Dr. Judd seemed to mean well, following are a few problems in his reasoning.
Brushing With Soap
Dr. Judd claimed that instead of toothpaste, brushing with soap is the way to go, stating that you only need 2 rinses to get soap off of your teeth.
Doesn't that mean that soap sticks to your teeth too? And if so, how many rinses is OK for something that you're going to use on your teeth? 2 is OK but 27 isn't? Is 5 OK?
Perhaps brushing with soap works, but there's actually glycerin in most bars of soap, so this is all very confusing indeed.
Sugar Doesn't Cause Cavities
Dr. Judd also claimed that sugar doesn't cause cavities.
Judd based this claim on what he saw after after adding sugar to bone material The bone material wasn't affected negatively by the sugar.
Of course that's not how cavities work. Sugar feeds the bacteria on the teeth which then deposit plaque on the teeth and then--you get cavities!
Bacteria Doesn't Cause Cavities
Judd said that since skeleton teeth buried in the ground didn't have cavities, despite being in contact with bacteria in the dirt, that bacteria doesn't cause cavities.
Of course there is no saliva in the dirt and the same carbohydrates and same strains of bacteria that are in the mouth are missing too.
This isn't to say that Dr. Judd was stupid and that everything he said was wrong. However, it seems that his overall views on dental health were overly simplistic and didn't take into account numerous important factors.
Evidence That Glycerin Is Actually GOOD for Your Teeth
So now that the sort of scary study about glycerin is debunked, and Judd's reasoning is debunked, let's talk about glycerin's positives.
Of course we're talking about other issues here more than what the FDA thinks about glycerin, but for the record, the US Food and Drug Administration recognizes glycerin as being safe.
There are also many studies showing that glycerin has beneficial properties.
While they aren't all directly applicable to dental health, you can easily see the connections.
Reduced Streptococcus Mutans (source)
Reduces Biofilm (source)
Promotes Healing (source)
Is Sorbitol Better for Toothpaste Than Glycerin?
Some natural toothpastes use sorbitol instead of glycerin since sorbitol also acts as a sweetener and helps keep toothpaste from drying out (but it doesn't have glycerin's preservative properties.
It's important to note that even though sorbitol isn't nearly as cariogenic (causes cavities) like glucose, it still can lead to cavities. So though it doesn't seem like a really big deal, technically it's not the best thing to have in toothpaste (source).
Benefits of Glycerin in Toothpaste
Instead of being a bad guy, here's why you should be glad glycerin is in your toothpaste.
Makes It Taste Better
Glycerin is sweet. So your toothpaste tastes better with it in there and you and your kiddos are therefore more likely to brush with it.
Prevents Toothpaste From Hardening (Becoming Cement)
Well, not really cement, but if you've ever left the cap off of your toothpaste, you know what I mean.
Glycerin is a humectant (it draws water to itself) so it helps keep toothpaste from drying out in the tube. Glycerin also has this function in my Moisturizing Homemade Foaming Hand Soap and it can be found in many skincare products and cleaners as well, to keep them (and you) from drying out.
It's Bacteriostatic (Kills Bad Bugs)
In light of the concerns about glycerin being unsafe for your teeth, this is really interesting to note. Not only does glycerin not stick to your teeth to prevent remineralization, but it so happens that it's bacteriostatic and antimicrobial.
That means it actually does a lot more than just keep your toothpaste from drying out--it's actually good for your teeth and can prevent cavities, periodontal issues, and even can help your teeth be whiter. (source)
Reduces the Need for a Preservative
When a formulation is 50% or more of glycerin, you shouldn't need a preservative, which is great. I like avoiding the use of preservatives in my personal care products whenever I can.
Water and aloe in personal care products, on the other hand, are bacteria and mold breeding grounds, so glycerin is a much better base for toothpaste.
Natural Remineralizing Tooth Products I Love
While there are lots of natural toothpastes and dental health products out there that have some great reviews, I have a few favorites.
Theodent has theobromine in it, which seems to have valid research behind it showing that it is just as good as, if not better than, fluoride at keeping teeth healthy.
Great tasting flavors too, including Chocolate Chip for the kiddos :).
I bought several of these toothpastes when I was finishing up this post and I LOVE them. So zingy and my mouth feels AMAZINGLY clean.
I love the alkalinizing philosophy--makes a lot of sense!
Code WHOLENEWMOM gets a nice discount too!
I also LOVE this mouthwash from this company. It took away sensitivity on a tooth after just one use, and at my last hygiene appointment, my (very picky) hygienist said that my teeth had very little plaque on them and asked if I'd changed anything.
The only thing I'd changed was that I started using the mouthwash from here. Their other products look pretty great too, but I. Love. This. Mouthwash.
Yes, it's not cheap but really you only need a teensy amount to get results. I try to stretch out my products whenever I can and you definitely can with this one. Just keep it in your mouth as long as you can.
Disclaimer: we'd just moved my hygiene appointments from 6 months to 4, so that might be part of it. However, when I started coming to their office I was on a 3 month schedule. So I think it's more likely that this product is doing amazing things. Time will tell.....
Note that all of these products have glycerin. If glycerine was a seriously scary tooth enemy, there's no way my dental health would have improved this quickly. Plus the good reviews on the products would likely not be there. I know--reviews aren't always trustworthy, but I'm super picky and I'm telling you my honest experience.
Glycerin is also in most remineralizing toothpastes on the market. I can't verify every positive reviews from those, but I think the science (and my results) speak for themselves.
So there you have it. Glycerin is not scary for the Tooth Fairy or for us, and in fact it can even be your teeth's friend. Maybe not their BFF, but at least they can and should hang out together.
In summary, glycerin is safe and non-toxic and likely beneficial for oral health. The myth that glycerin is harmful for your teeth is just that--an unverifiable myth.
Acknowledgement: Big thanks to Stephanie of Bubble and Bee for her help analyzing the study mentioned in the post. I had hunches about quite a few of the points regarding that, but her assistance was very helpful. She's a smart lady - and seems to have some great toothpaste too.
Hi! I am curious about hydrated silica. Most natural toothpastes have it as an ingredient but I have read opinions against its use stating that it is too abrasive for teeth and wears down the enamel. I don’t know what to think…any thoughts? Thanks!
This is a really good question. I don't know! I did some digging around today and it does seem that the advice is mixed. One of them that I mentioned (the Theodent) has it, while the Bubble and Bee does not.
I wonder if it would be a good idea to alternate to get the Theodent protection? Or maybe use the Bubble and Bee and the mouthwash?
I use so little of the mouthwash that one bottle is going to last me a long time.
I've reached out to Theodent about this :).
Hi again. I was just talking to a natural-minded dentist about this. She said to keep in mind that enamel has a hardness of 5, so you would want to not use anything harder than that on your teeth. It seems silica might be as hard as a 7, whereas hydrated silica is about a 5---so it's kind of on the fence. Hope that helps!
Are you aware that the 'miracle' mouthwash by ImmunizeLABS has sorbitol in it? Just wondering since you state it isn't good for the mouth via toothpaste.
I'm really not trying to be argumentative as I, too, read about glycerine in tp., I'm just trying to figure this out and make the best choice for me. I have diabetes related teeth and gum issues and really need to get the best for these issues.
I do thank you for the post and for the links....
Hi there. I don't see that it has sorbitol in there. In fact, it has erythritol and in the information about that, mentions that it's better than sorbitol for the teeth. Can you help me see where you are seeing that? Thanks!
I think you would love the products that I mentioned. I'm very very picky and my teeth feel super clean. I've been through a lot as well due to genetics and lyme and more. I hope you can find good solutions. I have also used the phototherapy patches for my teeth and seen good results - also trying out PEMF and this supplement which is great (affiliate link) https://iherb.co/gWXr8eyJ. I hope some of that helps. Please do respond about the sorbitol :).
OH, please forgive me, it was the Theodent that has the sorbitol:
Purified Water, Hydrated Silica, Sorbitol, Xylitol, Glycerin, Sodium Lauroyl Sarcosinate, Xanthan Gum, Titanium Dioxide, Citric Acid, Spearmint Oil, Sodium Benzoate, Stevia Extract, Sodium Bicarbonate, And Sugar-Free Vanilla Extract., Rennou(Tm) Theobromine, Calcium Acetate, And Sodium Hydrogen Phosphate
Yes, I saw that. And someone was asking me about hydrated silica too. I will reach out to them. I love the Rennou ingredient instead of fluoride but they seem to be a very thoughtful company so we'l see what they say. I can say that I have had a tough going w/ my teeth and since using this toothpaste things have been a lot better. I have continued to work on my health, but I have, I think, only had one cavity since switching to this.
I guess you had me until the kudos to the owner of a company that sells a product with glycerine in it! I ALWAYS question ANY company that MAKES MONEY from selling something with "questionable" ingredients and what THEY have to say about said ingredients.
I will have to make my own study on this topic (which, BTW EVERYONE should do) including the information here, but until my search is complete, I won't be putting or using toothpaste with glycerine in it on my teeth. I actually make my own anyway, but sometimes have to go to store bought stuff.
Hi Carol! I understand you questioning that but really there are posts on the internet from people selling toothpaste without glycerin saying that it's dangerous. So it all comes down to looking at the evidence and deciding what the truth is. I have bought tooth products without it and with it. I have poured over the evidence and my experience with tooth products that have glycerin in them is stellar.
If you can show me where the research that I did is wrong, I will absolutely reconsider what I have written and rewrite it to change it up if I can see that it is, indeed wrong. I have lost tons of money over the years (more than you would believe likely) walking away from companies and products where I found out that something that I thought was true wasn't.
And I will do it again if need be.
I've also likely spent more time correcting myself than anyone I know on the internet.
There is another argument out there about glycerin that I hope to make a video of that disproves it, but for now I can't do that. Will be at least a few weeks to iron out some technicalities.
I think it's very telling that for all the years (10+) that I looked into this, I never found ONE study showing that glycerin is a problem. The I thought I found it, and lo and behold, it actually shows the opposite. Would you agree or disagree with that?
Feel free to reach out to Stephanie yourself and see what you think about her intellectual integrity. So far I've been really impressed.
Adrienne, I do stand by my choice not to blindly believe something about a product that the sellers are making.
That said, I did NOT mean that I disbelieve your post at all. I just wanted to make it clear that this post, along with my own searching will be what makes me a believer or not about glycerine.
From this post, even though I read the same from Dr Judd, and took it to be true, I, too was startled about his other claims. I choose to do some of my own research to find MY answer.
I never meant to imply that your research was wrong, or even that it was incorrect in ANY way....did I say that?
I only said that I don't BLINDLY believe companies that make statements about certain ingredients in products that they make money selling. I have to do my own research, and that includes any sources they give.
And all of that to simply say I will be doing some more of my own research to find what MY decision will be...
Please allow that I do have the right to do that without being upset that I'm doing it!
I read your post and was curious about doing further searching of my own. That is all.
And I'm NOT questioning anyones intellectual integrity, SPECIFICALLY. Only companies in GENERAL...and that includes ALL of them that make claims about certain ingredients without trusted sources to back it up, and I'm NOT saying that those companies you listed have done anything improper as I haven't checked them out myself yet.
Again, please allow that I have that right as well without being upset that I'm doing it.
This post is only ONE of what will eventually be MY search for the truth of glycerine in toothpaste...I don't usually take only one view of anything before I make my own choices.
And I hope that I haven't offended you for doing so.
I'm not offended. I encourage you to do your research. I just don't think there's anything else out there. I would be surprised if there is. Loads of people are making the claim about glycerin being a problem but not one of them has a study to back it up. It's just them saying it.
I personally decide what I think is true, find products I like and then mention them and if I can make some income for sharing that information, I will do so. Not the other way around (going from money to putting forward an idea).
I reached out to 3-4 different companies about the glycerin study that seemed to show that glycerin was a problem. I bet that all / most companies saying glycerin is a problem don't even know that study exists since you will no one (except one commenter on one post--that's all I could find) stating that there is a study saying that glycerin prevents remineralization.
Stephanie was the only one that responded and her response was incredibly thorough, backing up a lot of what I was thinking already, but in more detail and with more facts.
I really don't think there is anything I didn't read, but feel free to send me anything you find to the contrary. If you find something, I might just have to hire you as a research assistant, LOL!
Hi again - to clarify, again I'm not offended but I am a bit surprised that you seem to think that I wouldn't consider someone's financial interest in saying that glycerin is good while selling a glycerin toothpaste. I always keep that kind of thing in mind and yet of course anyone can be misled / taken advantage of.
Maybe that's not what you were doing but that's what it seemed like to me.
As far as Stephanie goes, she had and has plenty of information as to why she thinks glycerin is fine in toothpaste which is way way more than anyone out there has (since they have nothing) to show that glycerin is a problem. In fact, it's very odd that this myth has been out there for so long since there really is no proof whatsoever that there's a problem. But again, I welcome the questioning and if you want to investigate, please do and come back and tell me what you find :).
OK, Adrienne, I'm ready to concede that Dr. Judd and the pub med article are not convincing enough that glycerin is unhealthy in toothpaste. However, I'm not ready to concede that it IS, either. None of the posts or article I have read in the past few hours give EVIDENCE or sources for their views, either for or against. The ones that say is is not healthy, give only Dr. Judd and the pub med article, which seems to me to be mostly about BLEACHING with those ingredients. But the posts or articles saying it IS healthy don't give much for proof, either. One, (https://truthpaste.co.uk/blogs/behind-the-truth/should-you-avoid-glycerine-in-your-oral-care-products) even gives the case for using propylene glycol: ANTI-FREEZE as a good ingredient in toothpaste!
So, although I am inclined to say it is ok, I'm not ready to totally agree with it in toothpaste.
I'll continue searching. I have left comments or emails to those saying it is not healthy asking for other links besides the pub med or Dr. Judd for "proof".
And those few that said it is healthy, I have also asked for link to support their theories for using glycerine for teeth.
I'll see, and let you know what I find.
I actually do have a section in my post that has some of the characteristics about glycerin that show that it should be helpful in toothpaste--did you see that part?
I would like to add more info to that section, but as you can imagine the post was taking a lot of time.
What do you think about the references in that section?
OK, here goes. I did not go past senior in High School (graduated), so I don't have the science background that you have.
That said, here is my take on the links that you gave.
Most of the studies, if I'm reading them right, are not related to the teeth specifically, but the skin and either burn wounds or ulcer wounds on the skin. My bet is that the red highlights won't transfer to this comment section, so I'll put them in quotes, and the ones in parentheses are mine.
PEG 1000 was the most effective antimicrobial vehicle while “glycerine was the least effective” on the basis of its MIC.
“Glycerine exhibited activity only at 100% concentration and, therefore, was the least effective antimicrobial.”
(Related to skin, not teeth)
It is well known that glycerin in high concentration will exhibit dehydrating effect on many systems including living cells by the commonly known process of osmosis
It has been shown that glycerin at high concentration will be cytotoxic to all cells that have been tested if they are exposed long enough. (again, deep burn wounds)
sterile intravenous normal saline solution containing “glycerin and amino acids.”
Biofilm has been implicated in such problems as urinary tract infections, endocarditis, cystic fibrosis and infections of prosthesis and heart valve. Invariably the only recourse for treating prosthetics such as mechanical heart valve is to have them replaced. Biofilms are present on the removed tissue of 80% of patients undergoing surgery for chronic sinusitis. (no mention of mouth or teeth)
“Topical glycerin can treat biofilm in the mouth such as halitosis.”
“As in the case outlined here it can diffuse a bacterial biofilm.” (Open Ulcer on leg)
Glycerin can assist antibiotics and the immune system in conquering bacteria biofilm. In this capacity it can reduce the ever-occurring resistance of bacteria to antibiotics. Cavity spaces such as the pleural cavity and the peritoneal cavity can develop infections with biofilms. “Infusing these cavities with the 3% solution of Glycerin would help breakdown these biofilms. For example, half a liter of the solution would be infused into a pleural cavity. A greater amount could be infused into the peritoneal cavity.”
(Must be injected into cavity)
After the use of the dentifrices twice daily for 3 months, the levels of mutans streptococci had not changed significantly in the sorbitol-treated group, whereas a significant reduction (p less than 0.0005) was found in subjects using the xylitol/glycerol dentifrice. (Xylitol/ glycerin combination)
So, that is my take on the links and sources.
Again, I don't think it is enough to show that using glycerin in toothpaste is going to do a lot...But there was also NO mention of it being difficult to clean off of teeth, or that is isn't difficult.
I'm still on the fence regarding glycerin in toothpaste after researching and reading studies almost all day.
I would agree with your thinking for the most part that it's not harmful but also not an amazing toothpaste ingredient, however breaking down biofilm is a great thing for the mouth. And a significant reduction of S mutans is nice too. I think the issue here is--what is the alternative? Sorbitol? Not a great alternative. What other things could be used in a toothpaste to keep it from turning hard? Aloe maybe but aloe causes bacteria growth easily.
Side note - I didn't take that much science in college. I was pre med but only for awhile. I am hoping to finish a health coach certification course soon and then hopefully on to something else but I only have so much time. Balance is elusive until the other side of eternity.