Glycerin is among the best natural moisturizers in the living systems. It has long been in use to prevent and treat skin dryness since it moisturizes the stratum corneum (SC). It is known as a humectant. Its skin care benefits also include attraction of moisture, osmoregulation of intracellular milieu, and maintenance of liquid crystallinity or fluidity of cell membranes and intercellular lipids.1

Dry skin is commonly experienced by a large number of people, and can be managed using moisturizers. Moisturizers help replace skin’s natural oils, cover tiny fissures in the skin, and provide a protective film. They seem to slow down the evaporation of the skin’s moisture, and maintain hydration.2 Humectants attract water when applied to the skin and improve hydration of the stratum corneum.2 Glycerin is a hygroscopic, nonvolatile, and viscous substance that works as a humectant.3 It is an effective moisturizer used in cosmetic products and a potential skin protectant. It hydrates the stratum corneum.3 It acts as a humectant primarily on account of its high hygroscopic property.4

Glycerol, or glycerin, prevents damage to the stratum corneum and helps in the rapid reconstitution of the protective skin barrier after damage, be it mechanical or chemical.4 Glycerin acts a humectant as it assists in absorption of water from the atmosphere and it reduces the evaporation rate from the skin surface. The action of glycerol both on stratum corneum hydration and barrier function is attributed to the AQP3 channel.3

Lodén et al5 suggested that glycerin containing cream is a suitable alternative to urea/sodium chloride in the treatment of atopic dry skin. Another study noted significant improvement in stratum corneum hydration and restoration of epidermal barrier function following treatment with glycerol-containing cream compared to the glycerol-free placebo.6

Thus, the hygroscopic property of glycerine makes it a potential humectant that helps in absorption of water from the atmosphere and reduces the evaporation rate from the skin surface, thus locking in moisture in the skin. Glycerin is one of the best natural moisturizers.

References

1. Orth DS, Appa Y. Glycerine: A natural ingredient for moisturizing skin. In: Dry skin and moisturizers – Chemistry and Function. Lodén M, Maibach HI (eds.). CRC Press; 1999.
2. Lynde CW. Moisturizers: What They Are And How They Work. Skin Therapy Letter 2001;6(13). Available from: http://www.skintherapyletter.com/dry-skin/how-moisturizers-work/.
3. Fluhr JW, Bornkessel A, Berardesca E. Glycerol — Just a Moisturizer? Biological and Biophysical Effects. Available from: http://www.scientificspectator.com/documents/personal%20care%20spectator/Glycerol%20a%20Moisturizer.pdf.
4. Roussel L, Atrux-Tallau N, Pirot F. Glycerol as a Skin Barrier Influencing Humectant. In: Lodén M, Maibach H (eds). Treatment of Dry Skin Syndrome. 2012; Springer, Berlin, Heidelberg.
5. Lodén M, Andersson AC, Anderson C, et al. A double-blind study comparing the effect of glycerin and urea on dry, eczematous skin in atopic patients. Acta Derm Venereol. 2002;82(1):45-7.
6. Breternitz M, Kowatzki D, Langenauer M, et al. Placebo-controlled, double-blind, randomized, prospective study of a glycerol-based emollient on eczematous skin in atopic dermatitis: biophysical and clinical evaluation. Skin Pharmacol Physiol. 2008;21(1):39-45.