What is "Diglycerin" and what is its utility?

Diglycerin is the INCI (International Nomenclature of Cosmetic Ingredients) name for the ingredient. It may also be referred to as glycerol dimer or diglycerol. As part of the glycerol ester family, diglycerin is present in nearly 0.33% of skin and/or hair care formulas. As a result, it is listed in the ingredients of certain face masks, creams, shampoos, serums for sensitive skin, and some exfoliating wipes. Diglycerin is used not only in the field of cosmetology, but also in the food industry. It appears as a food additive serving as an emulsifying agent, coating, gelling agent, or a carrier for colouring.

It is important to note that the majority of fatty substances of plant origin, particularly oils and vegetable butters, and those of animal origin used in the field of cosmetology are esters, belonging to the diglycerol family. These esters are a material resulting from the chemical reaction between fatty acids such as carboxylic acid and alcohol like glycerol. The main difference between vegetable oils and esterified oils lies in the production method. Vegetable oils extracted from biochemistry are naturally found in seeds or oilseeds and follow a physical process. Hot or cold pressure is commonly used. On the other hand, esterified oils are derived from natural fatty substances whose ingredients have been isolated in order to extract certain ones. The process follows the principles of green chemistry which replicates the natural process and avoids the use of petrochemical substances.

In the field of skincare, diglycerin is utilised for its moisturising properties. Skin hydration involves providing the necessary moisture for the various cells located deep within the epidermis. This promotes cellular regeneration and strengthens the hydrolipidic film that protects the skin's surface from the effects of various external aggressions. By regularly applying a skincare product containing a moisturising ingredient, the skin becomes supple, soft, and elastic.

Diglycerol also acts as a humectant agent at the heart of the skincare product. Indeed, it presents itself in the form of reduced size molecules that penetrate into the cytoplasm of the superficial cells of the epidermis to retain water there. These particles are hygroscopic, meaning they have a strong affinity for water, and act like sponges. Furthermore, the humectant function of diglycerin works just as well when the product is in its packaging as when it is applied to the skin.

Diglycerin is also used as a solvent in cosmetology skincare. Its role is to dissolve other ingredients in the formula that are not easily soluble.