Dermatologists are medical practitioners who are qualified to diagnose and treat disorders of the skin—the largest organ in the body. But what do these experts do to keep their own skin healthy and what kind of products do they use?

Steven Daveluy, a board-certified dermatologist with the Wayne State University School of Medicine, told Newsweek he uses a topical retinoid—a class of medications derived from vitamin A that come in a variety of different forms, such as cream, lotion, foam, emulsion or gel.

Topical retinoids are used to treat several skin problems, including acne, sun damage and psoriasis—a disease that results in scaly, itchy patches on the skin. But these drugs can also be applied to the skin for other reasons.

"I use a topical retinoid, since it helps reduce fine lines and wrinkles, even out skin tone, and keep your skin healthy," Daveluy said. "Adapalene is now over-the-counter, so that makes it available. There are also over-the-counter products that contain retinol, another retinoid."

Daveluy said he also uses topical minoxidil on his scalp, a drug that is used to stimulate hair growth and slow balding.

"I don't have any hair loss, and I don't know if I ever will, but I want to prevent it if I can," he said. "It's like brushing your teeth. You don't wait until they are falling out to start brushing. You brush now to keep them good. So, I use minoxidil solution to keep the hair I have and love."

Another board-certified dermatologist, Chris Adigun, told Newsweek she uses a gentle cleanser and a hyaluronic acid serum-moisturizer every day.

Hyaluronic acid is a naturally occurring compound found throughout the body, particularly in the eyes, joints and skin. This compound provides structure to the skin, while helping to keep it hydrated and elastic. But was we age, the body naturally loses hyaluronic acid.

There are numerous skin care products that contain hyaluronic acid, which can help to moisturize the skin and provide anti-aging benefits, among other uses.

"At night, I again use a gentle cleanser, followed by a hyaluronic acid serum, and another emollient moisturizer—if necessary, usually in the winter—followed by tretinoin," Adigun said.

Many people experience dry skin during the winter as a result of exposure to colder temperatures and air that holds less moisture, sometimes resulting in a rash. Emollient moisturizers are products that also soften and smooth the skin in addition to adding moisture. Tretinoin, meanwhile, is an example of a retinoid.

Jennifer MacGregor, a board-certified dermatologist with the UnionDerm cosmetic dermatology practise in New York City, told Newsweek she starts her daily skin care regimen in the morning with a splash of water to the face before swiping with a very mild blend of salicylic and glycolic acid.

These compounds, available in many over-the-counter products, are exfoliating acids that can have several benefits for the skin. Glycolic acid can reduce signs of aging and hyperpigmentation, while decreasing the appearance of pores, among other uses.

Salicylic acid—which is primarily used to treat acne—can also reduce hyperpigmentation, reduce the appearance of blackheads, and remove excess oil from the skin.

MacGregor then uses a skin care product containing anti-oxidants, which are naturally occurring compounds that protect our cells from damage. We consume anti-oxidants, compounds such as Vitamin C and E, through our diet and the body also produces some, but products containing these substances can also be applied topically to the skin.

They may help to reduce signs of aging, protect against sun damage, and help to reduce inflammation in the skin.

In the evening, MacGregor said she uses an oil cleanser or makeup remover, as well as a gentle hydrating cleanser. She also uses another moisturizer, which changes with the seasons.

All of the dermatologists said they use sunscreen every day on exposed areas to protect against sun damage and keep their skin healthy.

"Every day, I use a mineral-based sunscreen—it contains zinc oxide and titanium dioxide as its ultraviolet filters," Adigun said. "I use a brush on sunscreen to the tops of my hands and reapply as needed during the day."

If you do not protect your skin from the sun, you increase the risk of developing skin cancer, skin discoloration, hyperpigmentation, freckles, wrinkles, and leathery skin.

"[Sunscreen] will help prevent skin problems, including skin cancer, and skin aging," Daveluy said. "If you want beautiful skin for your whole life, sunscreen is your friend."

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