Dry skin is a common problem experienced by a large number of people. Moisturizers are commonly used to manage dry skin. Moisturizers replace skin’s natural oils and form a protective covering. They act by slowing down the evaporation of the skin’s moisture, and maintain hydration.1 Glycerin is a humectant. Humectants, when applied to the skin surface, attract water and improve hydration of the stratum corneum.1 Glycerol’s high hygroscopic property is responsible for its action as a humectant.2 It occurs naturally in skin.2,3This hygroscopic, nonvolatile, and viscous substance acts as an effective moisturizer and humectant in cosmetic products and a potential skin protectant. It acts a humectant due to absorption of water from the atmosphere and it reduces the evaporation rate from the skin surface.4Glycerol prevents damage to the stratum corneum and helps in rapid reconstitution of the protective skin barrier after damage.2 A randomized double-blind study evaluating patients with atopic dermatitis treated with either a moisturizing cream with 20% glycerin, its cream base without glycerin as placebo, or a cream with 4% urea and 4% sodium chloride noted that adverse skin reactions such as smarting were less common among patients using the glycerin cream compared with the urea-saline cream. Glycerin containing cream seemed to be a potential alternative to urea/sodium chloride in the treatment of atopic dry skin.5 Another study revealed significant improvement in stratum corneum hydration and restoration of epidermal barrier function following treatment with glycerol-containing cream compared to the glycerol-free placebo.6Glycerin is a potential humectant that plays a vital role in skin hydration as it attracts water and reduces the evaporation rate from the skin surface.

References

1. 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/.

2.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.

3. Tucker R. What evidence is there for moisturizers? Available from: https://www.pharmaceutical-journal.com/files/rps-pjonline/pdf/pj20110416_cpd.pdf.

4. 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.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.