Lets Talk Science

Let’s talk science: What is Glycerin?

Glycerin is something that has been getting a lot of attention lately. Ever since NikkieTutorials talked about the Nivea Men Aftershave Balm being a good makeup prolonging primer, due to the high glycerin content, people have been going mad for it. However, a lot of people don’t actually know what it is. So today, I want to talk a little bit about it so that you know exactly what it is that you’re putting on your skin.

Glycerin is one of those substances that you will find in the ingredients list of just about everything in your vanity, bathroom and even in your food. It’s uses really are that far reaching and varied. If you don’t believe me, take a quick check of your bathroom cabinet, I bet that you’ll find it listed somewhere.

So, what is it? Glycerin is a viscous, sweet, colourless and odourless, non-toxic liquid. At room temperature it has almost a syrupy texture, freezes to a gummy paste and has a boiling point of 290 °C. It is present in all natural lipids (fats), vegetable and animal, but can also be synthetically produced. In chemical terms is is classed as a Polyol (sugar alcohol). The chemical formula for Glycerin is C3H8O3.

Glycerin is what is known as a hygroscopic humectant. In short, that means that it attracts water from the air and draws it into the skin to help maintain a healthy moisture balance, or to rehydrate dry skin. It’s these properties that make glycerin an essential ingredient in moisturisers and lotions.

However, it should not be used upon the skin undiluted. Placed upon the tongue, it will cause a blister. Because it’s a humectant it will actually draw the moisture from the deeper layers of the skin and dehydrate them. So whilst the top layer would look hydrated, the skin underneath would be parched and suffering damage. So, when using glycerin always make sure that it is diluted in water or alcohol. Glycerin will not dissolve into oil.

Glycerin is a natural byproduct in the soap making process. Especially in handmade natural soaps. When lye and fats combine, they produce soap but they also produce glycerin. Makers of natural soaps will argue that their soaps are better because of the high content of glycerin, and it’s moisturising properties.


A quick note for cosmetic use, if you have allergies, check what your vegetable glycerin is made from. It is most often made from coconut or palm oils so if you’re sensitive to either of those, check your labels.


Due to it’s natural sweetness, glycerin is also used as a sweetener in foods, and is also used as a natural preservative, or a thickening agent in liqueurs. As a sweetener, you will find it listed in the ingredients as the E number E422. It is an attractive sweetening agent as it does not feed the bacteria that causes plaque and cavities. In food terms, glycerin is termed a carbohydrate due to it’s lack of proteins or fat.

You can also find glycerin listed as an ingredient in your medicine cupboard. It has lubricating properties, so you may find it in cough syrups or allergen immunotherapies. It can have laxative effects if used as a suppository or an enema. Or mixed with fruit juice and taken orally, it has immediate effects on elevated pressure in the eye.

Glycerin can also be used as an anti-freeze, features in the liquid used in E-Cigarettes and is the essential component in Nitroglycerine which is what is used to make explosives such as dynamite. Glycerin is not an explosive substance on it’s own.

So, as you can see, glycerin is so much more than “Superglue for the face.” Yes, it’s naturally sticky nature does make for a good makeup primer, but it does have many uses in many different aspects of life. You can find it in your bathroom, makeup kit, your kitchen, your car… so many things.

I wasn’t sure if this would be a post that would be interesting to many people, so if you read and enjoyed this please drop me a comment and let me know.

I research every ingredient of every product that I put onto my skin, due to my many sensitivities and allergies, so I’ve built up quite the little knowledge bank. So, if there’s any particular product ingredient that you would like to know more about then drop me a comment and let me know.

I hope you learned something cool today, and I shall see you next time!

Much love, Kim xo


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