Ingredient Spotlight: Glycerin

Glycerin is a type of moisturiser known as a humectant, which when applied to the skin acts like a sponge, attracting and holding water in the stratum corneum. Glycerin is pretty amazing – it can absorb its own weight in water, making it one of the most effective humectants known.[1] And while natural ingredients are not necessarily any safer than synthetic alternatives, the fact that glycerin occurs naturally in the body means allergic reactions are practically unheard of, meaning it’s ideal for people with sensitive skin.[1] When used in cosmetic products, glycerin is an effective moisturiser that helps support the skin’s natural barrier function.[1]

In order for your skin barrier to perform at its peak – keeping moisture in and irritants, allergens and pathogens out – the outermost layer of the skin, known as the stratum corneum, needs to keep its water content at around 20-30%,[2] and glycerin is a key player in maintaining this balance.[3] In fact, glycerin is so important that the skin has dedicated protein channels, called aquaglyceroporins (seriously though, how amazing is that?!), that are specially adapted to transport glycerin and water quickly between the layers of the skin.[4]

Glycerin is produced as a natural by-product of the body breaking down triglycerides within the sebaceous glands, which also releases free fatty acids – another essential component of the skin barrier.[3] As well as attracting and binding water, thereby assisting with that all-important moisture content level, glycerin may also help regulate the dynamic crystal structure of the skin barrier lipids, which can see-saw between purely liquid crystal (loosely packed lipids allows rapid water loss) and a solid crystalline phase (which is tightly packed but rigid). By acting a bit like a moderator, glycerin is thought to help maintain the optimal balance between flexibility and strength.[3]

Until relatively recently, most of the glycerin used for cosmetic purposes was manufactured from animal fats, where it is a by-product of soap production.03/12/2021 13:59:00 Today, cosmetic glycerin (including that used in the etch&ethos range, and any other Ego products for that matter) is increasingly produced from plant sources, like soy, palm or coconut oil, making it completely naturally derived.[5] By the way, if the mention of palm oil raises a red flag for you, don’t worry, our glycerin comes only from sustainable RSPO certified palm oil.[1]

[1]All our suppliers are either members of the RSPO or buy their products from members of the RSPO.

1.         Greive K. Glycerine: the naturally effective humectant. Dermatol Nurs 2012;11(1):30–4. 

2.         Silva CL, Topgaard D, Kocherbitov V, Sousa JJS, Pais AACC, Sparr E. Stratum corneum hydration: Phase transformations and mobility in stratum corneum, extracted lipids and isolated corneocytes. Biochim Biophys Acta BBA - Biomembr 2007;1768(11):2647–59.

3.         Roussel L, Atrux-Tallau N, Pirot F. Glycerol as a skin barrier influencing humectant. In: Lodén M, Maibach HI, editors. Treatment of Dry Skin Syndrome: The Art and Science of Moisturizers. Berlin, Heidelberg: Springer; 2012. page 473–80.

4.         Hara-Chikuma M, Verkman  a S. Roles of aquaporin-3 in the epidermis. J Invest Dermatol 2008;128(9):2145–51.

5.         Ciriminna R, Pagliaro M. Sustainable Production of Glycerol. In: Encyclopedia of Inorganic and Bioinorganic Chemistry. John Wiley & Sons, Ltd; 2016. page 1–8.