Urea Is Two Different Ingredients Depending on the Percentage. Our Only Urea Product Doesn't Print One.

Urea is in one of the fifty-six products we sell. One.

For an ingredient that has been in dermatology since before most of what we stock existed, that is a strange number. It turns up in almost every European pharmacy moisturiser and in most of the heel creams sold anywhere. In our catalogue it appears once, in a foot cream, filed by us as a keratolytic softener.

What it does not appear with, anywhere on that package, is a percentage. Which is the only thing about urea that determines what it does.

One product in fifty-six

The product is the Wellbeing Health Pharm GOUNBAL foot care cream, which scores 8.7 and sits in the bottom quarter of our catalogue. Its hero ingredient line reads urea, glycerin, hyaluronic complex. Thirty-three ingredients in total.

A foot cream is exactly where you would expect the higher-concentration behaviour to be wanted. Heel skin is thicker and more compacted than skin anywhere else on the body, and a humectant alone does not do much against a callus.

So the product type points one way. The label points nowhere.

Two jobs, one INCI name

The pharmacology is not in dispute, and it is unusual for being genuinely dose-dependent in direction rather than degree.

Urea is a small, water-loving molecule and part of what dermatology calls natural moisturising factor — the mix of solutes that keeps the outer layer of skin pliable by holding onto water. Adding more of it from the outside does the obvious thing. Skin holds more water, feels softer, and water loss through it drops.

Keep raising the concentration and a second behaviour appears. Urea is a denaturant: it interferes with the bonds and structures holding proteins in shape. Applied strongly enough to the stratum corneum it loosens the cement between corneocytes, and compacted keratin starts to come away. That is what a chemist means by keratolytic, and it is why urea shows up in prescription treatments for ichthyosis and thick plaque psoriasis rather than in a daily face cream.

One is a moisturiser. The other is a controlled demolition.

The number nobody prints

Here is where we have to be honest about the limit of this article.

There is a solid review literature on urea — a comprehensive review of the clinical literature from 2013, a pair of 2020 papers dealing separately with medium and with high concentrations, a systematic review from 2025 covering ichthyosis, atopic dermatitis and psoriasis, and a German two-part review going back to 1989. We know these exist. We confirmed their titles, journals and identifiers.

We could not open any of them this week. Every route we have to full text was either paywalled or refused us.

So we are not going to give you a threshold. We are not going to write "below ten per cent it hydrates, above ten per cent it exfoliates," because we have not read the papers that would let us defend the number, and a number quoted from memory is exactly the kind of thing this blog exists to be annoyed about. The shape of the pharmacology is settled. The boundary is a figure we would be inventing.

The formulator knows it. The supplier knows it. It is on a specification sheet somewhere. It is not on the tube, and there is no rule saying it should be.

The look-alike that does something else

Two more of our products contain something that reads like urea on a label and is not.

Hydroxyethyl urea appears in a PDRN spray serum and in a chamomile sleeping cream, both scoring in the high nines. It is a urea derivative built specifically as a humectant, and our data files it that way. It holds water. It does not do the second job.

That distinction is invisible to anybody scanning an ingredient list quickly, and it runs the opposite way to the usual worry. Here the derivative is the milder one, and the plain molecule is the one whose behaviour depends on a number you cannot see.

Two urea-family ingredients, three products, and no way to rank them from the packaging.

What our screening found

The practical takeaway

Use the product category as your proxy for the concentration, because you have nothing better. Heel and foot creams are formulated toward the keratolytic end. Face and body moisturisers with urea sit at the humectant end. A brand that wants you to know it went high will usually tell you, because the number is a selling point once it is large.

Silence, then, is informative in one direction only. No number on a foot cream means it is probably not a high-strength product, because high strength gets advertised.

Watch where you put it. The same cream that is right on a heel is wrong on a shin, and urea on skin that is already fissured or inflamed stings in a way that tells you immediately.

And if the heel is cracked deeply enough to bleed, or if there is a diabetic foot in the question, none of this is the right conversation. That is a clinician's problem and a foot cream is not the tool.

We publish every ingredient in our catalogue that carries our worst grade, and this product's colourant is on that list. The ten we flag most often and the method behind the numbers are on the awards page. If the humectant version is what you actually want, the chamomile cream carries the derivative instead and scores 9.8.