The Covid-19 outbreak has resulted in a global shift in daily routines, from transportation to personal hygiene. As the World Health Organization and national health authorities such as the CDC in the United States continue to issue guidance, a key theme has emerged: washing your hands should be a top priority of your healthcare regimen. In just 30 days, global searches for key terms like “how to wash hands” “handwashing” “hand health” and “dry hands” have growth exponentially.

As more people wash their hands more often, it’s important to focus on the science of skin care and educate ourselves about why our skin becomes dry, what you can do about it, and why certain emollients like Squalane work.

Why Your Hands Become Dry

In the simplest of terms our skin feels dry because it contains less water. Water travels between our skin’s three layers: epidermis (top), the dermis (middle) and the hypodermis (lower). Blood vessels deliver water to the dermis and moisture is then transferred to the epidermis. When water is lost through this process it is known as Trans Epidermal Water Loss (TEWL).

Is there a way to remedy TEWL? Yes. One factor in reducing water loss involves the Stratum Corneum, the epidermis’ surface. This natural skin barrier, made up of chains of corneocytes and proteins, acts as a shield to protect our skin and keep in moisture. When it is damaged, moisture is lost.

Especially during times of increased public health awareness, hand washing is a front-line defense, so we naturally do it more often: when we arrive back from the grocery store, before we cook, or even after handling devices like cell phones.

When we wash our hands, we’re washing the Stratum Corneum where dirt and harmful pathogens like bacteria and viruses are present. Soap is an incredible defense. Soap acts like a crowbar – its hydrophobic tail wedges into the lipid barrier of viruses, like Covid-19, and bursts open its contents like proteins which can then be washed away.[i] However, washing our hands also has other impacts: it can cause damage to proteins and lipids in our Stratum Corneum.[ii]

Why Moisturizers Work

Supporting a healthy Stratum Corneum can replenish our skins’ moisture. Using appropriate skin care such as moisturizers or barrier repair creams have been shown to be beneficial in the management of disease states where the Stratum Corneum permeability barrier is impaired.[iii]

Some moisturizers are comedogenic, acting as an impermeable layer that covers the Stratum Corneum. This function doesn’t allow moisture to escape.  Other moisturizers, like emollients, restore moisture to the epidermis by helping to fill the gaps in the protective chemical layers in our skin: those combinations of corneocytes and proteins that can break apart when moisture is lost. [iv]

Squalane as an Effective, Clean Moisturizer

Squalene is a naturally occurring molecule produced by the sebaceous glands in our skin. When it is hydrogenated, it becomes Squalane, a non-polar, fully saturated and very stable hydrocarbon that is easily incorporated into emulsions, and is compatible with most cosmetic ingredients. Squalane is an excellent moisturizer, keeping our skin and hair properly hydrated and imparting suppleness and flexibility to the skin. In addition, plant-based squalane, like sugarcane derived Neossance Squalane, is sustainable. Here’s why it works so well.

Squalane Reduces TEWL and is Noncomedogenic

Squalane can help nourish our skin after lots of handwashing because it helps reduce the loss of moisture as it moves from your dermis to your epidermis, preventing Trans Epidermal Water Loss (TEWL).  Skin barrier repair goes up when TEWL goes down.

Using a moisturizing lotion with Squalane or 100% Squalane application can quickly help keep hands moisturized. In in-vitro studies, the application of 100% Squalane 2 times a day improved skin barrier function, measured by a reduction in TEWL, by 4% after one hour and 14% after 2 weeks compared to no treatment in a study of 20 participants. Additional in-vitro studies with face creams containing Squalane demonstrate 18% reduction in TEWL.

In addition, 100% Squalane is noncomedogenic. It was tested by a panel of 6 volunteers between the ages of 22-42 three times weekly under an occlusive patch to the upper back during 4 weeks. Squalane was found to be non-comedogenic after a series of follicular biopsies were performed at induction and following the final patch removal at each test site.

Maintaining healthy hands is a small but important step in personal hygiene. So remember to support your Stratum Corneum and reduce TEWL after washing your hands.

% Reduction in TEWL After Application of Squalane

Clinical score on 20 men or women (Age 18+). Application of tested product* twice daily on the face for 14 days. *Test product: 100% Neossance Squalane Face Oil


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Hand Washing:

Ferris Jabr, “Why Soap Works”; New York Times,


Calderon, Julia; “Everyone Should Know the Difference Between the Three Types of Moisturizers”

Business Insider 2020

Rodan, Katie, MD; Fields, Kathy MD; Majewski, George, and Falla, Timothy PhD, “Skincare Bootcamp: The Evolving Role of Skincare” Plast Reconstr Surg Glob Open. 2016 Dec; 4(12 Suppl): e1152.

Dry Skin and Barrier Repair

Del Rosso, James Q. DO, FAOCD; Jacqueline Levin, DO. “The Clinical Relevance of Maintaining the

Functional Integrity of the Stratum Corneum in both Healthy and Disease-affected Skin.”

Elias, Peter M., MD. “Skin Barrier Function.” Curr Allergy Asthma Rep. 2008 Jul; 8(4): 299–305.

Rawlings, A. V.; Harding C. R. “Moisturization and Skin Barrier Function.” Dermatologic Therapy, 2004,

American Skin Association. “What is Dry Skin.”

Healthline. “Xerosis Cutis.”

Harvard Medical School. “9 ways to banish dry skin”


[i] “ Why Soap Works “ New York Times,

[ii] Del Rosso, James Q. DO, FAOCD; Jacqueline Levin, DO. “The Clinical Relevance of Maintaining the Functional Integrity of the Stratum Corneum in both Healthy and Disease-affected Skin,

[iii] Del Rosso, James Q. DO, FAOCD; Jacqueline Levin, DO. “The Clinical Relevance of Maintaining the Functional Integrity of the Stratum Corneum in both Healthy and Disease-affected Skin,

[iv] “How Does Moisturizer Work?” ACS,