What is Urea and its Benefits in Skin Care?

What is Urea? Chemical Structure of Urea

It often happens in the search for new therapeutic agents that some old stand-by is overlooked, whose luster has worn off, but which may have useful applications in moments when the miracle drugs falter. In the world of topical therapy, urea is such a drug. Youthful skin with a visible glow – it’s the holy grail of skincare. 

Albert Kligman

Updated 01/09/20

So, what if we told you the key to super-healthy skin and anti ageing is hydration?

Dehydrated skin causes horizontal lines to appear; the types that lead to deep-seated wrinkles, especially if not treated correctly.

That’s right; something as simple as keeping your skin plump and moist can ward off premature ageing for many years to come

But, shhh! There is one little “beauty secret” that not too many people know and that is Urea.

In our opinion, this ingredient is one of the most effective moisturisers in cosmetic chemistry – it’s role within the skin is quite remarkable; at low percentages it helps to maintain a healthy moisture balance, bringing much-needed relief to dry skin, whilst keeping it soft, supple, and youthful, at higher levels, it can help to encourage cellular renewal.

This is why it is used in dermatology, for both its keratolytic and hydrating properties. This dual effect gently exfoliates and moisturises at the same time.

It seems ironic to think that as far back as 1957, urea was viewed as a forgotten therapy despite being rediscovered by Dr. Kligman, the man behind Retin A. And yet, even today there is little information about what could be considered, the holy grail of the skincare world.

So, What is Urea?

Urea is a humectant, referred to as hydroxyethyl urea, not to be confused with the preservatives imidazolidinyl urea and Diazolidinyl Urea, which we discuss in more detail below.

It is a naturally-occurring substance found in the surface of the skin and is an active part of our natural moisturising factor (NMF), which functions to keep our skin lovely plump, supple, and working efficiently.

Urea is a natural component of our skin’s tissues and makes up 7% of our natural moisturising factor, along with 12% sodium PCA and 9% glycerol, all of which are water-binding – which is essential for maintaining the health, function, and hydration of the outer layer of skin.

Like many naturally occurring compounds in our skin, urea decreases with age and trauma from harsh ingredients and environmental pollutants, making the skin more susceptible to dryness, inflammation, and ageing.

From the many thousands of skins we have clinically treated over the years, we believe that inflammation and dehydration is the leading cause of premature ageing, the fact that urea has the potential to treat both of these concerns, it’s no wonder we refer to it as the veritable ‘fountain of youth’.

As if that isn’t enough from this wonder ingredient, when topically applied, those with dehydrated and dry skin can see an improvement in their symptoms of as much as 50%, and in those with eczema, as much as 80%.

There is also evidence to suggest, that urea helps to treat skin conditions such as ichthyosis, dermatitis, psoriasis, xerosis, and even nail fungus – all these conditions share a similar pathological cause — namely, a yeast called malassezia.

Urea’s Skin loving benefits

Hydrophilic: This term means “water-loving”, which gives urea its amazing ability to hold onto water molecules, keeping skin plump and moist and not only does it readily absorb water, but it also has a very high water content, which helps to reduce the amount of water lost through the skin.

On a molecular level, urea modifies the structure of amino chains and polypeptides within the skin, which is important for helping to moisturise the delicate tissues, there is a direct correlation between the skin’s water content and its levels of amino acids – basically the more dehydrated and dry the skin is, the lower its share of dissolved amino acids.

studies suggest that the keratolytic and hydrating effects of topical urea are owing to breakage of hydrogen bonds in the stratum corneum, loosening epidermal keratin, and increasing water-binding sites.

Improved barrier function: One of the many ways urea benefits the skin is by strengthening and protecting the barrier function, helping to keep it healthy.

Natural Exfoliant: At higher percentages within a formula urea becomes a natural keratolytic – exfoliator. This combined with its hydrating properties makes it a potent moisturising and exfoliating treatment, it works in synergy with ingredients that create the molecular structure of healthy skin, such as lactic acid helping other ingredients penetrate deeper.

Combined, these two ingredients actively work to remove dead skin cells and substances from the skin; improving cellular turnover and dramatically improve the water-binding ability of the skin, literally rebuilding healthy skin from the inside out.

Fights Acne: Urea further improves skin health by metabolising the antimicrobial peptide LL-37, which attacks acne-causing bacteria within the skin. An in vitro study also indicates that urea directly inhibits the yeast Malassezia, which is often the cause of fungal acne.

Possible Anesthetic: Urea has another interesting profile; it can create a local anesthetic effect on the skin and has anti-itch properties. This is really useful in helping to reduce cycles of inflammation and flare-ups, making it our product of choice for sensitive skin.

Penetration: Studies have found that urea plays a key role in increasing the permeability of certain skin care ingredients, working as a vehicle for other performance ingredients by encouraging them to penetrate the epidermis easily.

Natural Moisturiser: Dry skin can be due to a reduction of urea in the skin’s tissues, leading to tightness and flakiness. Urea is a key component of the natural moisturising factor found within the skin, offering instant relief to dry skin conditions.

For this reason, we include urea in H₂O Hydrating Complex and Quench ultra-hydrating water gel, both of which work as a moisture magnet to infuse dry, skin with moisture. The gentle exfoliating action of urea helps to leave the skin super smooth, especially when layered; the texture of the skin is visibly softer, giving it a youthful glow. In our clinic, we have seen some great results from both these formulas on our clients who suffer from extremely dry, dehydrated skin.

Testimonials

So you have heard it here from us first, ureas laundry list of skin-loving benefits

But if your still not convinced don’t just take our word for it, here are some of our client’s testimonial who have had great results at a varying percentages:

Lorree from Brisbane wrote

I use a cream called containing 5% carbamide/urea. I use it for my dry scalp issues and apply after showering, and it takes away all the dryness/flakiness.

 

Jane from London wrote

I have a carbamide cream at 10% that also contains Shea and a 30% foot gel for my partner. Both are working exceptionally well and this summarises why urea is such a fantastic ingredient. Thank you so much for writing this article.

 

Kathy from Auckland wrote

I started using your serum H20 with 1% Urea twice daily on my face. I have then been sealing it with my chosen moisturiser and am really impressed with the results, I am already noticing visible improvements in my skin it feels really hydrated and much smoother and it has its youthful glow back.

So happy that you introduced me to this wonder ingredient Samantha

 

John from Texas wrote

Initially, I began using a cream with 15% urea peeling but washed it off after 5min because it was irritating. Next, I tried 5-6% and it was still sensitising – small red bumps appeared on my higher cheeks and near the lipline. I switched to 2% and love it, it is really hydrating and I found it helps to prevent the dead skin buildup that often clogs my pores? I have a very sensitive skin, which doesn’t like actives like AHA/BHA and physical exfoliation.

 

Kelly a client wrote

I have suffered from eczema on my hands and neck and I have been using a 5% urea cream coupled with layering your Fortify barrier repair cream repair, a gentle no foam wash, and no exfoliating products at all. My skin is getting better, the texture is smoother, and not so irritated. I am so pleased with the results, thank you so much, Samantha, I wish you every success in the future and appreciate all you do, I agree it certainly is your calling.

The Sciencey Skin Bit

In order to understand how urea works, it is important to understand the skin’s structure, so please bear with us as we get a little technical here:

Your outermost layer of skin the stratum corneum – is made up of corneocytes and an intercellular cement which has a high resistance to many chemical agents. Inside the corneocytes is our natural moisturising factor (NMF), here a mixture of substances regulates moisture levels on the surface by binding water molecules.

Whilst applications of emollients and occlusive ingredients coat the skin’s surface to create instant moisturisation it is only a temporary fix, they don’t improve the skin’s ability to create and hold water the way urea does. When it is applied to the skin it penetrates the stratum corneum where it readily absorbs and retains water; increasing the capacity of the skin to hold moisture and rehydrate.

To conclude, it helps to regulate the cell cycle; encouraging natural desquamation or exfoliation, enhancing the barrier function, which in turn regulates the good micro-flora that keeps the acid mantle intact.

The Dry Skin Connection

Dry skin results from a lack of oil and water in the outer layer of skin, skin become scaly, cracked, and itchy.

Moisture is normally retained in the epidermis by a surface film of oils (sebum), broken-down skin cells, and natural water-holding substances. Urea is one of these water-holding substances, the others being lactic and amino acids.

As discussed previously, reduced levels of urea can lead to a lower water-binding capacity within the skin, which in turn leads to roughness, tightness, flaking, and irritation.

Research has found a link between severe dry skin conditions and drastically reduced amounts of urea in the stratum corneum. Urea stimulates the components of the skin that keep it healthy, which is referred to as epidermal gene expression. When applied topically, it increases the formation of filaggrin; an important protein found within the skin that keeps everything balanced. It also maintains a healthy barrier function, by building up the skin’s defense mechanisms.

Percentages Used in Skincare Products

Less than 10%: This can help with water retention in the skin, helping to bind moisture onto the skin. This is due to its extremely hydrophilic nature, making it a popular choice for its moisturising effect.

Over 10%: This has a light keratolytic effect, making it a great choice for those with dry, flaky skin that requires an extra boost. At this percentage, it is still hydrating, but it also becomes exfoliating, it can be quite irritating at this percentage when used on the face, but its ideal in body formulas.

At higher doses of 20-40%: It becomes a very strong keratolytic (exfoliator), making it great for more serious therapeutic uses, such as treating psoriasis and calloused skin on the feet.

Getting to Grips with the Different Types of Urea

Urea is often referred to as Carbamide, the primary organic solid of urine, which is waste that has been produced by the body after it metabolises protein.

Thankfully, the urea used in the cosmetic industry is made from synthetic sources and is not animal-derived. It is formed from ammonia and carbon dioxide and can be produced in either a solid or liquid form.

There are three forms of urea found in personal care products: Hydroxyethyl Urea, Diazolidinyl Urea, and Imidazolidinyl Urea. People often get confused by these, but they are, in fact, completely different ingredients.

Diazolidinyl and Imidazolidinyl Urea are antimicrobial preservatives used in the skincare industry to protect personal care products from bacteria, yeast, and mold. They do get a lot of bad press as a preservative due to the fact that they are proven to release formaldehyde. Hydrovance (INCI name “Hydroxyethyl Urea”) is a potent humectant and considered safe as a cosmetic ingredient.

The naked truth

Phew! With so many beautifying properties, we appreciate its a lot to take in

For the benefit of those who require a little recap, here are this cool little ingredient’s best bits:

  • urea is naturally produced by our skin
  • it regulates our skin’s moisture content and is an essential component of our Natural Moisturising Factor (NMF)
  • urea is hygroscopic – it is able to bind moisture on to the outermost layer of our skin
  • it is the perfect treatment for dry skin, it has anti-itch and anti-microbial properties
  • it can help to prevent acne-causing bacteria
  • it is also keratolytic at higher percentages, meaning it breaks down the connections between dead skin cells; naturally exfoliating the skin and helping ingredients penetrate further

285 thoughts on “What is Urea and its Benefits in Skin Care?

  1. Stephanie M Chung says:

    Hello, great questions and enlightening responses thanks except not asked is can UREA be safely used for genital and anal eczema itches?

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