Glycerol: A ubiquitous staple of skin hydration

Have you ever wondered how your favourite moisturiser makes your skin feel soft, smooth, and supple?1 There is a good chance that glycerol, an ingredient first recognised for its beneficial effects on the skin over 90 years ago, underpins the hydrating effect of your favourite skincare products.1

When it comes to skincare, it is important to have ingredients that you can rely on to support healthy, hydrated skin. In this article, we shine a spotlight on glycerol, how it works, and why you should look for it in your skincare products.

What is glycerol?

Also known as glycerine, glycerol is a potent humectant that has powerful hydrating effects.1 Glycerol is a common ingredient in topical skin preparations to promote hydration and can be injected intradermally to achieve deep hydration.1,2

Glycerol is a simple molecule that is extremely hydroscopic, which means it strongly attracts water1 and it is this water-attracting property that is responsible for glycerol’s beneficial effects on the skin.1

Glycerol is naturally produced by our bodies as part of the skin’s Natural Moisturising Factor (NMF), alongside other components.1 Working alongside other components of the NMF, glycerol helps to maintain adequate skin hydration and skin barrier health.1 In addition, glycerol can pass through aquaporins, which are proteins that channel the flow of important hydrating substances to the skin’s layers.1 Together, they play a key role in maintaining skin’s moisture balance, helping it to feel smooth and comfortable.3

Glycerol Diagram

How does glycerol work in the skin?

Glycerol is a humectant, which means that glycerol can both attract and hold water. This means that when glycerol is present in the layers of your skin, it both draws water from its surroundings and locks it in place, improving the skin’s water content and hydration levels.1

“Glycerol’s ability to attract and preserve hydration makes it a potent humectant, a property which underpins many of its key benefits.”1

Moisturiser products typically contain a combination of humectants (molecules which introduce water to the skin), emollients(molecules which introduce oil to the skin) and occlusives (molecules which prevent water loss through the skin).4 Glycerol is used extensively as a hydrating humectants in skincare products such as gels and lightweight moisturising products.4

Glycerol is one of the most effective humectants: it is a simple, small molecule which means that it can penetrate deep into the skin’s layers. An important property of glycerol is that it does not evaporate away, which means it remains in the skin exerting its effect for a longer period of time.5

Face Hydration

Why is skin hydration important?

Our skin is constantly exposed to the elements, which can strip it of its natural hydration and oils.1 Hydrated skin is more likely to look and feel healthy. It has been shown that low hydration levels can hinder the activity of other molecules in the skin, like proteins and enzymes.6 Some of the benefits of including glycerol as a staple in your skincare include:

Skin moisturisation: Glycerol spreads easily into the layers of the skin where it is able to attract and retain nearby water.1 This effect is sometimes referred to as ‘bulking’, which further helps your skin to feel plump and healthy, minimising fine lines and wrinkles.7

Skin barrier maintenance: Glycerol has been shown to interact with the skin barrier to help maintain its integrity.1 Boosting the protective and hydrating function of the skin barrier prevents water loss and shields against external stress from the environment.1,4

Boosts skin elasticity: Glycerol’s effect on the outermost layers of the skin boosts elasticity and hydration, helping your skin feel supple and healthy.1 When skin elasticity is optimised, it is better able to resist mechanical stress from body movement, like rubbing, stretching, and compression.1

Skin cell turnover and renewal: Our skin naturally undergoes a turnover process to shed old skin cells and reveal fresh, healthy skin.1 Glycerol’s water-attracting properties actively support this natural turnover process, resulting in improved skin appearance and overall skin health.1 By helping in the removal of dead skill cells, glycerol promotes more radiant skin.8

It is also important to consider which ingredients are used to attract water to the skin. While all humectants can attract water, glycerol stands out due to its ability to be transported by aquaporins, which are protein channels in the skin. This means that glycerol can pass deeper into the skin’s layers and exert its beneficial effects, providing deep hydration.9

Glycerol for skin hydration

Glycerol is one of the simplest, yet most powerful ingredients in your toolbox when it  comes to caring for your skin. Including glycerol-containing products in your skincare routine can promote skin hydration and can offer several benefits by helping to moisturise the skin, maintain the skin barrier, boost elasticity, and support skin cell turnover and renewal.

References: 1. Fluhr JW, et al. Br. J. Dermatol. 2008;159:23–34. 2. Hertz-Kleptow D, et al. Clin Cosmet Investig Dermatol. 2019 Aug 13;12:563-572. 3. Rawlings AV, Matts PJ. Stratum corneum moisturization at the molecular level: an update in relation to the dry skin cycle. J Invest Dermatol. 2005 Jun;124(6):1099-110. 4. Barnes TM, et al. Pharmaceutics. 2021;13(12):2012. 5. (Zhang 2014) Zhang H, Grinsta MW. Macromol Rapid Commun. 2014;35(22):1906-1924. 6. Haftek M, et al. J Drugs Dermatol. 2021;20(4):s3-s9. 7. Batt MD, et al. J Soc Cosmet Chem. 1988;39:367-381. 8. Schwartz J, et al. J Drugs Dermatol. 2016;15:1289;1294. 9. Hara-Chikuma M, et al. Physiological roles of glycerol-transporting aquaporins: the aquaglyceroporins. Cell Mol Life Sci. 2006 Jun;63(12):1386-92.