French Girls Swear By This Under-The-Radar Ingredient To Smooth & Hydrate Skin

With new products, brands, and categories popping up every day, beauty can be a bit overwhelming. Back to Basics is our rudimentary beauty series that serves as your crash course on the science behind some of the best formulations in the game.

When you’re dealing with ultra dry skin — be it cracked feet and rough elbows, or something more extreme like bumpy keratosis pilaris or scaly eczema rashes — classic moisturizing ingredients like glycerin and shea butter just won’t cut it. Enter urea, the hydrating powerhouse that’s renowned for treating more extreme dry skin conditions.

A metabolite that naturally occurs in the body, urea is found in blood and in the skin, and, yes, also in urine. For this reason, it doesn’t necessarily have the most, err, glamorous associations — but fear not, the urea found in lotions and creams isn’t actually derived from pee.

“This compound is the main nitrogenous breakdown product of protein metabolism in mammals and is excreted in urine,” says board-certified dermatologist Dr. Dianne Davis . “It’s also a component of the natural moisturizing factor (NMF) produced by the skin.” However, as cosmetic chemist and co-author of Skincare Decoded Gloria Lu explains, the urea that’s found in skin care lotions and creams is typically created synthetically in a lab, not derived from urine or other bodily fluids. “In skin care, it’s a helpful small molecule that acts as a powerful hydrating ingredient that can soothe itchy skin,” she says. “At higher levels, it can act as a keratolytic (aka, an exfoliant) to help shed stubborn, overdo skin cells,” she says.

So how exactly do you use it correctly to benefit your skin? More on the best practices for urea ahead.

How To Use Urea

According to cosmetic chemist and Skincare Decoded co-author Victoria Fu, what makes urea such a standout ingredient is the fact that it’s been tested on and proven effective for patients with atopic dermatitis and eczema. “It not only temporarily hydrates the skin, but it improves skin barrier function in the long-run,” she says. Additionally, a 2013 study has shown that urea can increase skin permeability, meaning it can help your other products penetrate your skin on a deeper level, thus making them more effective.

Not all urea products are created equal, however. Over-the-counter creams, lotions, and cleansers can contain anything up to a 40% urea concentration, with anything over 10% considered to be on the stronger side. According to board-certified dermatologist Dr. Rachel Nazarian, products with lower concentrations are used for their moisturizing and softening abilities, while stronger, higher concentrations are best for keratolytic activity and dissolving away thick or scaly skin (like with eczema or keratosis pilaris, aka those pesky chicken skin bumps on the back of your arms and/or legs).

How and when you use a urea product will depend on both its concentration and formulation, but as a general rule of thumb, she recommends using urea facial products weekly and body products daily.

In addition to skin care, urea can also be found in various nail care products, as it helps (especially when formulated with a higher concentration) to soften thickened and brittle nails, improve the appearance of discoloration, as well as help any antifungal medications better penetrate the nail to cure infection.

What To Look For With Urea Formulations

When it comes to pairing urea products with other ingredients, Dr. Nazarian says that she typically recommends using it alone. “Combining it with other exfoliating ingredients may make it too irritating,” she says. “Occasionally, however, it can be combined with glycolic acid or other exfoliating acids, but this is strictly for deeper removal of thick skin, such as for the heels of the feet or thick keratin conditions such as keratosis pilaris.”

Exfoliants aside, Lu says it pairs well with other moisturizing and reparative ingredients. “Like urea, glycerin is another well-tested humectant, and niacinamide and ceramides are great for skin barrier function,” she says. “Combining all of these ingredients is great for supporting your skin’s barrier health.” Remember — a stronger skin barrier means less water loss and overall more hydration for your skin. Dr. Davis adds sorbitol, hyaluronic acid, and sodium PCA proteins to the list of compatible humectants. And in the case of nails, urea is usually paired with an anti-fungal medication to treat fungal infections.

Who Is A Good Candidate To Use Urea?

According to the experts, urea generally works well for all skin types and tones. Fu points out, however, that any products containing a high concentration of urea should be patch tested first in order to avoid any possible irritation. “With any new product, you should always do an initial patch test to make sure your skin is happy with it,” she says.

Since it’s great for dissolving thicker, rougher patches of skin, it can also be quite beneficial for anyone dealing with skin conditions such as keratosis pilaris, atopic dermatitis, and eczema. However, Dr. Davis warns against applying it on any open cuts or abrasions. “If it’s used aggressively (via vigorous rubbing or scratching or used on open skin, it can cause burning or irritation,” she says. Remember — for rough or dry patches on your body, you’ll see the best results with daily product application.

Overall, urea is a proven and effective treatment for dry, rough, or scaly skin, and Fu explains that for this reason, it’s become quite popular in both Europe and Japan. “In fact, there are full skin care lines centered around the benefits of urea,” she says. “We’ve found that some people hear of urea and think it sounds very…unglamorous, but it’s actually a pretty helpful ingredient for keeping skin healthy and hydrated. It deserves a chance!”

Below, eight products with urea to incorporate into your routine.

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