Complete Guide to Vegetable Glycerin

Vegetable glycerin generally appears in the form of a fairly viscous and thick liquid, colorless and odorless. It is generally obtained by saponification of oils of… plant origin, as you would have guessed from its name!

What is saponification? 
Saponification corresponds to the chemical reaction allowing soap to be obtained. During this reaction, a fatty substance, associated with a strong base, often soda, makes it possible to obtain soap but also another product: the famous glycerin.

triglycerides of fatty acids + soda → soap + glycerin

Glycerin can then be extracted and used for its many properties in cosmetics and domestic use.

Humectant and hydrating: Vegetable glycerin helps attract and retain water thanks to its hygroscopic properties, so it will help maintain perfect hydration on the skin. Obviously, you must respect the recommended dosages ;)

Skin protection: The hydrating and humectant properties of vegetable glycerin help maintain a certain balance of the hydrolipidic film. The skin barrier will only be reinforced to protect the skin from external aggressions.

Emollient: Vegetable glycerin is an excellent emollient, meaning it softens and softens the skin but also the hair. It makes the treated areas more supple.

Lubricant: Glycerin is often used as an excipient in pharmaceutical products such as cough syrups or suppositories for example.

Solvent: Vegetable glycerin is very often used to facilitate the extraction of plant active ingredients in the preparation of hydroglycerinated plant macerates, for example. It also plays a preservative role by absorbing water conducive to microbial development.

Stabilizer and thickener: In a cosmetic product, vegetable glycerin can promote a certain stability to your product, especially in the case of emulsions.

For use in cosmetics, vegetable glycerin must be added and dosed between 2 to 8% in an aqueous phase. Beyond this percentage, the humectant effect of glycerin reverses. It attracts all the moisture it finds, even that present in the skin and hair, and can then on the contrary dry them out. In addition, glycerin is of real interest if the ambient air is humid, it will capture humidity to position it on the skin and hair for example. Otherwise, if the ambient air is dry, the glycerin risks drying out your skin or hair by absorbing the water it finds in them.

Please note that vegetable glycerin is suitable for all skin and hair types, particularly for dry and dehydrated skin and hair. It is added to most aqueous cosmetic products. It must be mixed well so as to disperse it throughout the preparation. Do not hesitate to carry out skin tests on small areas, some skin may react badly.

• In a cream, a milk, a cleansing gel, a lip balm: Add vegetable glycerin at a maximum rate of 2 to 5% to your preparation.

• In a shampoo or shower gel: Add 2 to 8% vegetable glycerin to shampoo or shower gel. The dosage may be higher for a rinsed product.

• For specific care, very dehydrated skin: Use vegetable glycerin dosed between 8 to 10% in agreement with a health professional.

Obviously, in an ecological and responsible approach, we favor the use of glycerin of plant origin. However, you are aware that glycerin can have various origins:

• Synthetic: it is obtained from petrochemical derivatives such as propylene. It is sometimes possible to find it in products under the name Propylene glycol.

• Animal and obtained by saponification of animal fats: beef fat is most often used.

• Vegetable and obtained by saponification of vegetable oils. In this category, the big winners are: coconut oil, palm oil, rapeseed oil, sunflower oil, soybean oil… Do not hesitate to check its origin and quality.

Please note that you can find glycerin in many hygiene or cosmetic products. Be sure to check its origin. Whether it is of plant, animal or synthetic origin, it appears under the INCI name “Glycerin”. However, if the glycerin is vegetable, the “vegetable” mention should be highlighted ;)