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Glycerin (Glycerol)

What is glycerin?

Glycerin is chemically a sugar alcohol [1]. On the Nutrition Facts labels, it is included in total carbohydrates, and, as a subcategory, in sugar alcohols [2]. In the EU, glycerin is listed as E number E422.

Glycerin Word Origin and Meaning

From French glycérine, from Greek glukeros = sweet [13].

Nutrition Facts:

  • Calories per gram = 4.3
  • Glycemic index (GI) = ?
  • Sweetness, relative to sucrose = 75%
  • Net carbs = probably 100%

Glycerin, Glycerine and Glycerol Are the Same

Glycerin, glycerine and glycerol are 3 names for the same substance. The name glycerin or glycerine is usually used as a product name and the name glycerol for the ingredient, for example, glycerin syrup contains 99.7 glycerol.

Glycerol vs triglycerides. Glycerol naturally occurring in foods and in the human body is usually joined with fatty acids and forms triglycerides, which are lipids, but again, glycerol as a standalone molecule is not a lipid but carbohydrate. When triglycerides are digested, they are broken down into glycerol and fatty acids, which are absorbed.

Formula

The chemical formula of glycerin (glycerol) is C3H5(OH)3.

Glycerol or Glycerin Formula Picture

Picture 1. Glycerol structure

Glycerin Absorption and Metabolism

Glycerin is chemically classified as a sugar alcohol, but it is more similar to sugars: it is readily absorbed and is probably converted into glucose in the human body and it provides 4.3 kilocalories of energy per gram [2,3]. Glycerin is not one of the FODMAPs (fermentable oligo-, di- and monosaccharides and polyols), because it is well absorbed in the small intestine and does not pass to the large intestine where it would be fermented by intestinal bacteria.

Glycerin is often mentioned as a sweetener with a low glycemic index, but there are no reliable sources to confirm this.

Types of Edible Glycerin

Vegetable glycerin is made from vegetable oils (palm oil, palm stearin, palm kernel oil, coconut oil, soybean oil) during production of soap or biodiesel.

Animal glycerin is a natural byproduct of animal fats (such as beef tallow) during production of soap.

Synthetic glycerin is produced from cane or corn syrup sugar, or propylene (a petroleum derivative).

Glycerin as a Food Additive

Food-grade glycerin may be added as a humectant (wetting agent), thickener, solvent or sweetener to dairy products (cream), canned goods, confections, fondant, processed fruits, jams, energy bars and other foods. The source of glycerin (animal or vegetable oil, corn syrup, petroleum) used in a food product is usually not revealed on the food labels.

Other Glycerin Uses

  • An emulsifier in pills, syrups, toothpastes, mouth washes, fluoride gels, tobacco, etc.
  • Anhydrous glycerin is used in fluoride gels, and is approved as an over-the-counter (OTC) anti-caries drug by US Food and Drug Administration (FDA) [14].
  • A lubricant, enema or laxative, as a suppository is used to treat constipation.
  • Oral glycerin, as a drug, is used to lower high pressure within the eye (glaucoma).
  • Intravenous glycerin can be used to treat brain swelling (cerebral edema) [7].
  • Glycerin may be used as a skin or hair moisturizer.

Possible Glycerin Health Benefits

In some studies, glycerin in doses about 30 mL/kg body weight slightly (by 2.6%) increased hyperhydration and endurance performance, but additional research is warranted [12].

Glycerin Safety

Glycerin as a food additive is Generally Recognized As Safe (GRAS) US Food and Drug Administration (FDA) [6]. Glycerin is expected to be safe to use by adults and children [7]. Glycerin has no known cancer-promoting (carcinogenic), DNA-damaging (mutagenic) or birth defect-causing (teratogenic) effects [4].

During Pregnancy

Glycerin is category C substance, which means side effects were possibly observed in animal fetuses but not in human fetuses due to lack of human studies [7].

Side Effects, Dangers

Glycerin as a sweetener used in foods does not likely cause any side effects.

Glycerin as a laxative can cause dry mouth, nausea, headache, diarrhea, excessive urination (polyuria) and eventual dehydration [7].

In individuals who are sensitive to palm or coconut oil, vegetable glycerin may trigger allergic reactions.

Liquid Glycerin (Syrup) and Cooking

Glycerine

Picture 2. Glycerin is a thick, translucent liquid
(source: Wikimedia, Creative Commons licence)

USP-grade* or food-grade glycerin syrup properties:

  • A translucent, thick, viscous syrup, without odor; contains 99.7% of glycerol [8,9]
  • 75% as sweet as sucrose [2]
  • Highly hygroscopic – readily attracts moisture [11]
  • Soluble in cold and hot water and in alcohol [4]
  • Melting point = 64.4°F (18°C) [8]
  • Boiling point = 554 °F (290 °C) [8,11]

* USP = US Pharmacopeia

Frequently Asked Questions

1. Is glycerin vegan?

  • Vegetable glycerin is usually vegan, but yeasts or bacteria may be used during the purification process.
  • Synthetic glycerin is vegan.
  • Animal protein is not vegan.

2. Is glycerin syrup appropriate for diabetics?

Currently, the effect of glycerin on blood glucose levels is not known; it may be similar to the effect of table sugar.

Related Nutrients

  1. Sugar Alcohols  American Diabetes Association
  2. Freeman J. et al, 2004, Low-Carbohydrate” Food Facts and Fallacies  Diabetes Spectrum
  3. Elia M et al, 2007, Energy values of macronutrients and specific carbohydrates in foods  European Journal of Clinical Nutrition
  4. Glycerin MSDS  ScienceLab
  5. Current EU approved additives and their E Numbers  Food Standards Agency
  6. SCOGS (Select Committee on GRAS Substances)  US Food and Drug Administration
  7. Glycerine (oral route)  PubMedHealth
  8. Glycerin  ChemSpider
  9. Glycerin specifications  SRS International
  10. Glycerine ─ boiling and freezing points  The Engineering ToolBox
  11. Glycerol  INCHEM.org
  12. Goulet ED et al, 2007, A meta-analysis of the effects of glycerol-induced hyperhydration on fluid retention and endurance performance  PubMed
  13. Glycerine  Dictionary.com
  14. Anticaries drug products for over-the-counter human use [21CFR355.3]  US Food and Drug Administration

73 Responses to "Glycerin (Glycerol)"

  1. Lynn says:

    can vegetable glycerin be used as laxative glycerin??

  2. Mtn Lady says:

    Can it be frozen to prolong shelf life?

    Thanks.

    • Jan Modric says:

      Mtn Lady, I’m not sure what would happen if you freeze glycerol. The problem is that the smell can change. To prolong shelf life of glycerol, you can keep it in a container that allows squeezing out the air that remains above the liquid.

  3. Ryan Andree says:

    Do you know how to make food grade vegetable glycerin from coconut oil? Every place I look mentions lye. I cannot find out how to do it anywhere

    • Jan Modric says:

      Ryan, you may want to contact some glycerine producer – most companies now how online websites…We here only describe effects and side effects of nutrients, not their production.

  4. Indrajeet says:

    What is the intention of wine and beer producers they are adding glycerin in wine?
    And is there any side effect after consumption of glycerin added alcohol? Please leave a reply.

    • Jan Modric says:

      Indrajeet, glycerin in beer is used as a preservative and in wine as a sweetener. In wine, some glycerin can be naturally present. Glycerin is very much like sugar (glucose or sucrose), so in amounts as usually used in foods, it should have no side effects. I’m not aware of any evidence that glycerin would cause hangover.

  5. Dana Callaway says:

    When using vegetable glycerin as an oral suspension for exzema, what is a safe dosage and should it be mixed with water?

    • Jan Modric says:

      Dana, where is the eczema? In moth or on the skin? For skin eczema, you put glycerin on the skin. Skin creams for eczema may have 20% glycerin or so.

  6. Queen says:

    Can glycerine take orally

  7. v.s says:

    We are using kor company’s glycerine, what should be the ratio of it to avoid dryness
    In motichur and bundi laddu

  8. Aniva Hansen says:

    My son is a rower. He is about to attend a regatta on a lake at a high altitude. The last time he was at this lake, he said it was difficult to breathe. He described breathing as being very uncomfortable and causing a stinging/burning sensation in his mouth/lungs. One of the other rowers suggested he take glycerin tablets to help “coat his mouth” and reduce the stinging sensation. That rower didn’t have any suggestions as to what he should buy – I am not even sure his recommendation was anything more than an idea. I have done some research on this and cannot find anything that suggests that glycerin will “coat the mouth” or assist to counteract the side affects of high altitude training. Do you have any comments at all?

    • Jan Modric says:

      Aniva, glycerin is pretty much like sugar and I’m not sure if it would coat the mouth. There are other polyols, like sorbitol and xylitol (check the menu in the upper right corner), that have a strong “cooling effect,” which can relieve scratchy feeling in the mouth and throat.

      Some people with Sjogren syndrome, who have dry mouth, believe that Coenzyme Q10 helps prevent dry mouth, but I personally cannot say if this really works.

      If your son experiences these feelings only at high altitudes, the problem is probably lack of oxygen in the blood. The only prevention I can think of would be going to the place few days earlier in order to acclimate.

  9. Sara Khan says:

    Can glycerin be used on the face?

    • Jan Modric says:

      Sara, there are glycerin creams that are intended for skin care. I’m not sure what would happen if you apply the liquid food-grade glycerine on the face…

  10. Elena says:

    I use glycerin in my electronic cigarette and I noticed that I have very loose stools since I started. Could it ve due to glycerin ? I vape about 5 ml per day. Is it a large amount ?
    Thank you.

    • Jan Modric says:

      Elena, glycerin is used as a laxative – usually in the form of suppositories, but I guess it may have the same effect if used as you described.

  11. denise says:

    Can glycerine bp be used in cooking? Tia

  12. Gorgeous says:

    I am currently eating a dirt that is somewhat low carb. I find conflicting data on whether glycerin would hindery progress. Ijust made homemade sugar free ice cream, and it was delicious with this as a sweetner! However, this morning I feel very weak. Any suggestions?

    • Jan Modric says:

      Gorgeous, glycerine is categorized as a carbohydrate and even, if it is chemically a sugar alcohol, it resembles sugars a lot: it has 4 Calories per gram and is converted to glucose in your body.

  13. I want to use food-grade glycerin to make non-alcoholic vanilla extract. I will place vanilla beans in a mason jar with about 1 cup of glycerin. While the extract is “brewing” I plan to keep in a dark pantry for several months. Some people say glycerin should be refrigerated during the brewing and after glycerin bottle has been opened. Is this true? Will it spoil? What is its shelf life?

    • Jan Modric says:

      Lucy, until the glycerine bottle is closed, its shelf life–according to labels–is usually 2-3 years. When opened and kept in warm area it can go bad in “less than a year” — from what I’ve heard. Refrigeration would probably help, but I can’t guarantee that what you plan, will go well.

  14. Alex Chaouk says:

    If i put a small amount on my babies dummy for a long period of time can this cause constipation?

  15. lee says:

    Glycerin is indeed a FODMAP. It is a P – polyol. Look it up.

  16. Minq says:

    Is it safe to add glycerin for skin care to my cream when pregnant?

    • Jan Modric says:

      Minq, glycerine is pregnancy C substance, which means not enough studies in humans have been done to know if it is safe for the unborn babies. A pharmacist in some drug store should know better.

  17. VINAY says:

    WHAT EFFECT WILL GLYCERINE HAVE ON POPCORN PRODUCTS? ALSO HOW CAN I USE IT IN SUGAR SYRUP THAT IS HEATED?
    HOW MUCH DO I USE IN THE SYRUP?

  18. Albazah Ayman says:

    Hi, I am enjoying reading glycerin comments, I have a question, can I add food glycerin to raw honey to keep it from thickening when I add Ginseng, Long jack and other powder ingredients ??

    • Jan Modric says:

      Albazah, you can add glycerin, but I can’t say if this will work or not for the purpose you’ve mentioned.

  19. Abd Kuddus Shaik says:

    Q : Hi..to what extent is animal glycerine used in the production of food , soap and cosmetic products. Would non animal glycerine be a much cheaper option..in production of foodstuff, soap and cosmetic products..?
    Is there a different Code for non animal glycerine..? Thank you.

  20. Soap World says:

    Hi,
    We developed a special soap calculator able to calculate the % of Glycerin inside the Natural Soap, because mixing oils and caustic soda, the reaction produces soap and also glycerin.
    The Soap calculator is here: http://www.soapworld.biz/soap-calculator-handmade-soap.html
    Bye !

  21. Tiger says:

    What does Sinar Glusp mean in regards to glycerine. Is it used for something different?

  22. Sabrina says:

    I am still confused as to if my walmart product USP Glycerin Anhydrous is the same as a vegetable glycerin. I know that what I need to use for my cosmetic recipes is the vegetable glycerin, however not sure how safe the walmart product is and if it is the same with a different type of name…

    • Jan Modric says:

      Sabrina, we here on Nutrients Review deal with nutrients, not cosmetics. There’s one thread on Reddit from which I conclude the glycerine you are speaking about is vegetable. Or go to the producer home page and find info there or ask them.

  23. Sabrina says:

    Thank you. I found my answer. It is soy based vegetable oil.

  24. Karen says:

    What about storing water in large totes that had been previously filled with Glycerin? Would be drinking this water be safe?

    • Jan Modric says:

      Karen, glycerin by itself is not toxic, but glycerin may promote the growth of bacteria, so any container that had glycerin in it should be disinfected.

  25. Jean says:

    Hi! I’m pregnant now and I’m I using glycerin oil all over my body as moisturizer because I’m allergic in any lotions I bought in the market.Is this safe to use throughout my pregnancy and can’t harm my baby? thank u for the reply..

    • Jan Modric says:

      Jean, here on Drugs.com it’s mentioned that Food and Drug Administration (FDA) did not classified a certain glycerine ointment in any pregnancy category, so this means it’s kinda “not known.”

  26. sergio radulovic says:

    almost every vitamin what I take daily has glycerin in it and I am trying to keep my blog sugar lower…any suggestions please?

    • Jan Modric says:

      Sergio, it is opportunity to ask yourself if you need to take vitamins at all. Vitamins without sweeteners are available, though.

  27. Walter says:

    Does anhydrous glycerine contain small amounts of alcohol, other solvents, or water that can’t be removed in the purification process? Do those other ingredients determine whether or not a particular glycerine is food grade?

    • Jan Modric says:

      Walter, I can’t answer this directly, but I’ve read somewhere that it is “USP grade” label that makes glycerine “food grade.” So, USP grade is food grade even if not specified as such. A more reliable source of information would be a producer of a certain glycerine product or a pharmacist.

  28. Moushmi says:

    In pharmaceutical application, where glycerin is mostly used? Do it have any side effect? will glycerin consumption increase in pharmaceutical application?

  29. aslam says:

    glycerin can apply on under the babe tongue?

  30. Hussein says:

    Why we may use glycerin as preservative in dextrose based syrup?

  31. Saku says:

    Can I use Glycerol BP 100% make my icing? Is it safe to eat?

  32. Javaria says:

    I am currently drinking pharmacy glycerin to cure severe bad throat ..is it ok or not? It kindoff helps for a little while..can u please also share the side effects of drinking it directly..and please also suggest the amount of glycerin i should use for this purpose.

    • Jan Modric says:

      Javaria, I believe drinking glycerine can give you some sort of temporary symptom relief. This effect is similar to scratching when you have itchy skin. It does not treat anything, it just distract your body from the annoying feeling.

      I do not recommend drinking glycerine for this purpose. The obvious side effect would be weight gain, because glycerine is similar to “pure sugar” – it’s very calorie dense.

      You may wat to figure out what is the cause of your bad throat. Did you go to a doctor?

  33. Zuri says:

    Hi, does vegetable glicerine affect in the increase of triglycerides in humans?

    • Jan Modric says:

      Glycerine or any other carbohydrate by itself does not increase triglyceride levels. It is a diet that contains more than 60% calories from carbohydrates that can raise triglyceride levels in some people.

      • Zuri says:

        Thank you Jan, I quit smoking a couple of months ago, but my triglyceride levels have raised. I thought maybe it could be because I am vaping ejuice made from 80% glycerine and 20% propylenglicol. I guess I’ll have to watch my diet then.

  34. Steve says:

    We recently bought a “duck jerky,” dog treat made in Germany. It list “glycerin” in the ingredients. We notice a sheen to the dog treats. Is it likely they are coated with glycerin for some reason — perhaps to keep them moist? We are not so concerned about having this in our dog treats, but a friend of ours is convinced it is some type of poison. In fact, these same treats, and chicken ones, were causing many pet deaths when they were made in CHINA. They disappeared for a few years, but have now returned from a new origin. I am certain the issue was not glycerin with the Chinese treats. Your thoughts on glycerin in/on dog treats would be much appreciated. We want to talk our friend down, if this is possible.
    Thank you very much for this resource!

    • Jan Modric says:

      I did not cover the effects of nutrients on animals on this website, but after a quick search, I think glycerin should be safe for dogs. As you suspected, the problem can arise from other substances, such as methanol, which can appear as a byproduct, when glycerin is produced from biofuel (diesel).

      You can find the answer on several websites if you search Is glycerin bad for dogs?

      • Steve says:

        Thanks, Jan. Just a quick look and there is a lot of information. Definitely not a fan of any treats from China. But would like to think the Germans would use a food-grade product for a “food,” even if it is for dogs.
        Take care.

  35. jhayar almazan says:

    sir how about pure glycerin is that toxic??tnx

    • Jan Modric says:

      By pure glycerine, do you mean the one you can get in the drug store? It may be safe, but you need to ask the pharmacist, who can answer this for every specific glycerine brand/product.

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