Urea

Urea in Skincare Formulations

Urea is highly water-soluble, powerful humectant and keratolytic agent used in skincare to hydrate, soften, and smooth the skin. Naturally found in the skin’s natural moisturizing factors (NMF), urea helps draw moisture into the skin and improves its ability to retain it. At lower concentrations (around 2–10%), it deeply hydrates dry or rough skin, while at higher concentrations (above 10%), it can exfoliate dead skin cells and treat conditions like keratosis pilaris or eczema. Urea is especially effective in repairing dry, cracked, or callused skin.

Formulation and Usage Suggestions

You do NOT need to premix Urea; it dissolves easily and is at most a weak electrolyte. Always add it directly to the batch during the cooling phase in your oil-in-water emulsion.

• 2–5%: Acts as a humectant, improving skin hydration and elasticity.

• 10%+: Begins to show mild keratolytic (exfoliating) effects, helping soften rough or calloused skin.

• 20–40%: Strong exfoliation, commonly used for thickened skin (heels, elbows, psoriasis treatments). May cause mild stinging or irritation, especially on sensitive or broken skin. 

Avoid using high-dose urea on freshly shaved or damaged skin.

Urea Works well in both humid and dry environments but should be combined with occlusives in dry climates to prevent transepidermal water loss (TEWL).

Urea exhibits optimal stability and effectiveness within the pH range of 6 to 8. In formulations with very low pH, it may degrade and become less effective.

Best Ingredients to Pair with Urea

Urea pairs best with other humectants such as glycerin, sodium PCA, and hyaluronic acid to boost moisture retention. It also complements barrier-repair ingredients like ceramides and panthenol to help prevent water loss.

Ingredients to Avoid Pairing with Urea

Ingredients to avoid when using Urea in your formulations  include strong acids and low pH actives. For instance, L-Ascorbic Acid (Vitamin C) is a no-go since Urea loses its potency in acidic environments. Also, high concentrations of AHAs and BHAs can lead to over-exfoliation and skin sensitivity. Additionally, be cautious with strong preservatives and reactive ingredients like formaldehyde-releasing preservatives (DMDM Hydantoin, Imidazolidinyl Urea), as they can cause Urea to break down into ammonia, making it unstable. Lastly, avoid highly alkaline ingredients since a pH above 8 can also degrade Urea.

📌 Formulation Tip: Keep urea in a balanced pH range and avoid pairing it with low-pH exfoliants or highly alkaline ingredients.

Formulating with Urea

 When using urea, it’s essential to consider your intended application. For facial creams, serums, and body lotions aimed at hydration, a concentration of 2–5% is ideal. In contrast, for products designed for exfoliation, such as foot creams, treatments for rough skin, or anti-aging formulations, a concentration of 10% or higher is recommended. Stabilizing Urea: To effectively stabilize urea, it’s crucial to monitor the pH of your formulation. Maintaining a pH range of 6–8 will help prevent degradation and ensure optimal effectiveness. Enhancing Delivery Systems: To further improve hydration and minimize irritation, consider combining urea with other ingredients like glycerin, sodium PCA, or panthenol. For body care formulations, incorporating occlusives such as shea butter or squalane can enhance moisture retention. Preservation Considerations: Be mindful of your choice of preservatives. It’s best to avoid formaldehyde-releasing preservatives, as they can lead to the breakdown of urea. Understanding Texture and Sensation: Urea is highly water-soluble, making it suitable for lightweight gels, serums, and lotions. For creamier formulations, balance the composition with emollients and occlusives to prevent the risk of over-exfoliation.

📌 Pro Tip: In anti-aging or hydrating formulations, use 2–5% urea with HA, ceramides, and panthenol for a balanced, deeply moisturizing product.

Conclusion

Urea is an incredibly versatile ingredient known for its hydrating, skin-softening, and gentle exfoliating properties. In concentrations of 2–5%, it functions as a humectant, making it excellent for moisturizing and repairing dry or damaged skin. When used at higher levels (10–40%), it effectively loosens dead skin cells, which is beneficial for treating thick, rough, or calloused areas. To achieve optimal results, urea should be formulated within a pH range of 6–8 and combined with hydrating and barrier-supporting ingredients. In dry settings, it’s best to use it alongside occlusives to safeguard against moisture loss. It is advisable to avoid mixing it with low-pH acids or potent preservatives, which could lead to degradation or instability. When properly formulated, urea becomes a robust skincare ingredient that not only boosts hydration but also improves skin texture and promotes a healthy, resilient barrier.