Skin hydration is important to relieve dryness and tightness, improve flexibility, and build better barrier so the skin can withstand environment insults. Skin Inc products are ideal for moisturizing since they contain high levels of ingredients known to hydrate skin.
For example, Vitamin C Serum contains 10% butylene glycol, 8% glycerin, and 3% pentylene glycol. That’s a total of 21% hydrating ingredients. As another example, Pure Onsen Mist contains 7% glycerin, 12% butylene glycol, and 1% hyaluronic acid. That’s a total of 20% hydrating ingredients.
These ingredients have been shown in many published technical studies to be effective in skin hydration, even at levels much lower than those present in Skin Inc products. In these studies, hyaluronic acid is particularly effective in hydrating the skin surface, while the small liquid glycerin and glycol ingredients readily enter the outer layers of skin to hold water and hydrate the tissue. And once the ingredients are inside the outer layers, they resist removal by washing, thus maintaining skin hydration for hours.
Importantly, these moisturizing ingredients are effective across many formulation types, for example, in emulsions, lotions, gels, creams, serums, and mists. Thus, they are very versatile cosmetic agents.
It is worth noting that hyaluronic acid and glycerin are moisturizing materials found naturally in the skin. So using them as cosmetic hydrating agents is replenishing the loss of these materials that occurs with aging. And for glycerin, the skin even contains a protein (Aquaporin) that transports glycerin and water in the skin for hydration. So using glycerin for hydration is indeed the right natural choice for skin.
Additionally, it is worth noting that hydration improves skin barrier. A healthy skin barrier is critically important for holding water in the skin and preventing entry of irritating materials such as detergents. Barrier damage contributes to several skin problems, such as dryness, itch, sensitivity, and redness. Hydration creates a healthy normal environment inside the skin, which allows the skin to begin healing damage to the barrier. In fact, hydration with ingredients such as glycerin is often used as part of therapeutic approaches for managing more serious problems such as dermatitis, dandruff, and blemishes.
While daily hydration alone will not solve all skin problems, it is a good foundation on which to build an effective skin care routine. Using the skin's own natural hydrators (glycerin and hyaluronic acid) is a good start. And supplementing them with other moisturizing glycol ingredients (such as butylene glycol and pentylene glycol) provides even greater effectiveness.
Technical references
Bissett DL and McBride JF, Skin conditioning with glycerol, Journal of the Society of Cosmetic Chemists, 34, 317-326 (1983).
Wickett RR and Damjanovic B, Quantitation of 24-hour moisturization by electrical measurements of skin hydration, Journal of Wound Ostomy & Continence Nursing, 44, 487-491 (2017).
Evans RL, Turner GA, Bates S, Robinson T, Arnold D, Marriott RE, Pudney PDA, Bonnist EYM and Green D, Human axillary skin condition is improved following incorportation of glycerol into the stratum corneum from an antiperspirant formuation, Archies of Dermatological Research, 309, 739-748 (2017).
Milani M and Sparavigna A, The 24-hour skin hydration and barrier function effects of a hyaluronic 1%, glycerin 5%, and Centella asiastica stem cells extract moisturizing fluid: an intra-subject, randomized, assessor-blinded study, Clinical, Cosmetic, and Investigational Dermatology, 10, 311-315 (2017).
Ventura SA and Kasting GB, Dynamics of glycerine and water transport across human skin from binary mixtures, International Journal of Cosmetic Science, 39, 165-178 (2017).
Tomiie A, Shinozaki M, Yamada T and Kurivama J, Moisturizing effects of diglycerol combined with glycerol on human stratum corneum, Journal of Oleo Science, 65, 681-684 (2016).
Harding CR, Matheson JR, Hoptroff M, Jones DA, Luo Y, Baines FL and Luo S, A high glycerol-containing leave-on scalp care treatment to improve dandruff, SkinMed, 12, 155-161 (2014).
Bjorklund S, Andersson JM, Pham QD, Nowacka A, Topgaard D and Sparr E, Stratum corneum molecular mobility in the presence of natural moisturizers, Soft Matter, 10, 4535-4546 (2014).
Alber C, Buraczewska-Norin I, Lockerbitov V, Saleem S, Loden M and Engblom J, Effects of water activity and low molecular weight humectants on skin permeability and hydration dynamics – a double-blind, randomized and controlled study, International Journal of Cosmetic Science, 36, 412-418 (2014).
Jeong CB, Han JY, Cho JC, Suh KD and Nam GW, Analysis of electrical property changes of skin by oil-in-water emulsion components, International Journal of Cosmetic Science, 35, 402-410 (2013).
Draelos Z, Aquaporings: an introduction to a key factor in the mechanism of skin hydration, Journal of Clinical and Aesthetic Dermatology, 5, 53-56 (2012).
Draelos ZD, Male skin and ingredients relevant to male skin care, British Journal of Dermatology, 166 (S1), 13-16 (2012).
Fluhr JW, Dralenski R and Surber C, Glycerol and the skin: holistic approach to its origin and functions, British Journal of Dermatology, 159, 23-34 (2008).
Lee AR and Moon HK, Gravimetric analysis and differential scanning calorimetric studies on glycerin-induced skin hydration, Archives of Pharmacal Research, 30, 1489-1495 (2007).
Kim E, Nam GW, Kim S, Lee H, Moon S and Chang I, Influence of polyol and oil concentration in cosmetic products on skin moisturization and skin surface roughness, Skin Research and Technology, 13, 417-424 (2007).
Verdier-Sevrain S and Bonte F, Skin hydration: a review on its molecular mechanisms, Journal of Cosmetic Dermatology, 6, 75-82 (2007).
Sato J, Yanai M, Hirao T and Denda M, Water content and thickness of the stratum corneum contribute to skin surface morphology, Archives of Dermatological Research, 292, 412-417 (2000).
Pedersen LK and Jemec GB, Plasticising effect of water the glycerin on human skin in vivo, Journal of Dermatological Science, 19, 48-52 (1999).
Vyumvuhore R, Tfayli A, Manfait M and Baillet-Guffroy A, Vibrational spectroscopy coupled to classical least square analysis, a new approach for determination of skin moisturizing agents’ mechanisms, Skin Research and Technology, 20, 282-292 (2014).
Heuschkel S, Wohlrab J, Schmaus G and Neubert RH, Modulation of dihydroavenantramide D release and skin penetration of 1,2-alkanediols, European Journal of Pharmaceutics and Biopharmaceutics, 70, 239-247 (2008).
Harada S, Horisawa E, Kano S and Sugibayashi K, Formulation study of topically applied O/W lotion containing vitamin D3 derivative, focusing on skin permeability of the drug, Drug Development Industrial Pharmacy, 37, 917-925 (2011).
Rawlings AV and Harding CR, Moisturization and skin barrier function, Dermatologic Therapy, 17, 43-48 (2004).
Potts RO, Buras EM and Chrisman DA, Changes with age in the moisture content of human skin, Journal of Investigative Dermatology, 82, 97-100 (1984).
lyondellbasell.com, Skin Hydration Test Using Various Glycols (2006).
Qassem M and Kyriacou P, Use of reflectance near-infrared spectroscopy to investigate the effects of daily moisturizer application on skin optical response and barrier function, Journal of Biomedical Optics, 19 (8): 087007 (2014 (on-line publication).
Harding CR, Matheson JR, Hoptroff M, Jones DA, Luo Y, Baines FL, and Luo S, A high glycerol-containing leave-on scalp care treatment to improve dandruff, SkinMed,12, 155-161 (2014).
Bowe WP and Kircik LH, The importance of photoprotection and moisturization in treating acne vulgaris, Journal of Drugs in Dermatology, 13, S89-94 (2014).
Duman G, Aslan I, Yekta Ozer A, Inanc I, and Taralp A, Liposome, gel and lipogelosome formulations containing sodium hyaluronate, Journal of Liposome Research, 24, 259-269 (2014).
Jegasothy SM, Zabolotniaia V and Bielfeldt S, Efficacy of a new topical nano-hyaluronic acid in humans, Journal of Clinical and Aesthetic Dermatology, 7, 27-29 (2014).
Nolan K and Marmur E, Moisturizers: reality and the skin benefits, Dermatologic Therapy, 25, 229-233 (2012).
Chiang C and Eichenfield LF, Quantitative assessment of combination bathing and moisturizing regimens on skin hydration in atopic dermatitis, Pediatric Dermatology, 26, 273-278 (2009).
Lynde C, Moisturizers for the treatment of inflammatory skin conditions, Journal of Drugs in Dermatology, 7, 103801043 (2008).
Yosipovitch G, Dry skin and impairment of barrier function associated with itch - new insights, International Journal of Cosmetic Science, 26, 1-7 (2004).
Andersen F, Hedegaard K, Petersen TK, Bindsley-Jensen C, Jullerton A, and Andersen KE, Anti-irritants I: dose-response in acute irritation, Contact Dermatitis, 55, 148-154 (2006).
Draelos ZD, Concepts in skin care maintenance, Cutis, 76 (6S), 19-25 (2005).
Ghali FE, Improved clinical outcomes with moisturization in dermatologic disease, Cutis, 76 (6 S), 13-18 (2005).
Wilson D and Nix D, Evaluation of a once-daily moisturizer used to treat xerosis in long-term care patients, Ostomy Wound Management, 51, 52-60 (2005).
Hawkins SS, Subramanvan K, Liu D, and Bryk M, Cleansing, moisturizing, and sun-protection regimens for normal skin, self-perceived sensitive skin, and dermatologist-assessed sensitive skin, Dermatologic Therapy, 17 (S1), 63-68 (2004).
Batt MD and Fairhurst E, Hydration of the stratum corneum, International Journal of Cosmetic Science, 8, 253-264 (1986).
Atrux-Tallau N, Romagny C, Padois K, Denis A, Haftek M, Falson F, Pirot F, and Maibach HI, Effects of glycerol on human skin damaged by acute sodium lauryl sulfate treatment, Archives of Dermatological Research, 302, 435-441 (2010).
Breternitz M, Kowatzki D, Langenauer M, Elsner P, and Fluhr JW, Placebo-controlled, double-blind, randomized, prospective study of a glycerol-based emollient on eczematous skin in atopic dermatitis: biophysical and clinical evaluation, Skin Pharmacology and Physiology, 21, 39-45 (2008).
Fluhr JW, Gloor M, Lehmann L, Lazzerini S, Distante F, and Berardesca E, Glycerol accelerates recovery of barrier function in vivo, Acta Dermato-Venereologica, 79, 418-421 (1999).
This technical summary was prepared by Donald L. Bissett, PhD. Dr. Bissett earned degrees in chemistry and biochemistry, and worked for over 32 years in skin care research in the cosmetic industry. Since 2008, he has served as a skin science technical consultant. His discoveries led to development and use of many active ingredients in skin care products that are on the market today. He is author of over 60 published technical manuscripts and inventor on over 30 US Patents.
February 12, 2019
