Look at some of your regular store-bought cosmetics, like your makeup, skin care, or hair-care products, and you may find listed there the ingredient “urea.” Doesn't sound too appetizing, does it? Turns out that it's not.
Used as a preservative and/or a moisturizer, urea can increase your risk for contact dermatitis, and has also been shown to release formaldehyde—a carcinogen.
It says it's moisturizing, but what ingredient is it using to actually moisturize?
What is Urea?
You may have heard that urea comes from urine. In a way, that's true. Urea is an organic, waste compound produced by the body after metabolizing protein. The liver breaks the proteins down in a process that produces urea. The urea is then excreted by the kidneys in the urine. Urea is also excreted through sweat, and regular healthy skin has a small amount of urea on the very outer layer.
Urea in cosmetics, however, is man-made in the laboratory. Same chemical formula, just synthetically made. The raw materials are ammonia and carbon dioxide. Not something you'd think you'd put on your skin, right?
Manufacturers like it, though, because it slows the loss of moisture from a product during use, helping to extend shelf-life. Urea also makes it easier to add certain ingredients to a formula, maintaining pH balance. It also slightly alters the skin's structure, allowing other chemicals to penetrate deeper into the skin, which can increase the effectiveness of certain products. Finally, it increases the moisture content in the top layers of skin, so after you use a product with urea in it, you're likely to feel like your skin is soft and supple.
What Products Contain Urea?
Urea can be found in a large number of products, including the following:
- Facial moisturizers
- Facial cleansers
- Anti-aging creams
- Body lotions
- Eye creams
- Shampoos & conditioners, styling mousses and foams
- Acne treatments
- After shave
- Lip balm/treatments
- Sunless tanning products
- Cuticle treatments
- Nail polishes
Why Are People Concerned About This Ingredient?
There are three main concerns with this ingredient. They include:
- Releases formaldehyde: According to a study published in 2010, ureas can release formaldehyde, which has been classified as a human carcinogen. In addition, the test found a clear relationship between patch test reactions to formaldehyde-releasers like urea and contact allergy to formaldehyde.
- Can be irritating: According to the Material Safety Data Sheet on this substance, urea can cause skin and eye irritation, and prolonged exposure can cause reproductive effects.
- Tendency to cause allergic reactions: Whether related to its tendency to release formaldehyde or not, urea has a tendency to cause allergic reactions. Those with sensitive and infected skin are advised to steer clear of this ingredient. In fact, the American Academy of Dermatology has established diazolidinyl urea as a primary cause of contact dermatitis.
How to Avoid Ureas
As I always say, why use ingredients on your skin that a) provide no benefit, and b) are potentially harmful? Though ureas may be slightly moisturizing, there are far better and healthier moisturizers, such as honey, shea butter, aloe, and more. Fortunately, you can easily find urea on product labels. Avoid anything that lists the following:
- Diazolidinyl urea
- Imidazolidinyl urea
- DMDM hydantoin
- Sodium hyroxymethylglycinate
Do you avoid urea? What products do you use that stay away from this ingredient?
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Photo courtesy lupetto2012 via Flickr.com.
De Groot A, “Formaldehyde-releasers in cosmetics: relationship to formaldehyde contact allergy,” Contact Dermatitis, January 2010, http://www.ncbi.nlm.nih.gov/pubmed/20136876.