Veronica asks, “I heard that using lotions with water is actually bad for your skin because as the water evaporates it removes the skin’s natural moisture and oil. Is this true?’
TBB: There are two fundamental ways that lotions can moisturizer your skin: one way is to provide an occlusive barrier that prevents the moisture that’s already in your skin from evaporating. That’s what ingredients like, petrolatum, mineral oil, silicones and so forth do. The technical term for this is reducing TEWL or Transepidermal Water Loss.
The second way lotions work is to attract moisture to you skin using an ingredient that has an affinity for water. We call these ingredients “humectants” and they are things like glycerin, sorbitol, and hyaluronic acid. They essentially bind water to the surface of your skin.
The best skin moisturizers use both mechanisms to moisturize skin. And the best way to do that is through an emulsion that’s a combination of oil and water.
This brings us back to Veronica’s question – what about the water that’s contained in the cream or lotion? What does it do?
There’s enough water in a lotion or cream to give your skin a little quick moisture boost which the oils and other occlusive agents can lock in your skin. Let’s be clear – most of the moisturizing effect comes from preventing the loss of what’s already in your skin, but it doesn’t hurt to add that extra little topical boost of moisture.
Right, some of that extra water will be absorbed by your skin and some of it will evaporate but that process of evaporation doesn’t cause any harm to your skin. It’s not going to cause the loss of skin’s natural moisturizing capacity in any way. So what Veronica has heard about lotions is just a myth. BUT I can see where this myth may have got its start.
It could have come from the fact that soaking your skin in water is not good for it. That swells the skin cells and does allow leaching out of some water soluble moisturizing components like urea and sodium PCA. But that only happens when your skin is submerged in water for a considerable period of time.
So I could see some clever marketer taking this little half truth and then saying that skin care products that contain water are bad for skin so they can sell you their special oil based product that doesn’t contain water. But it just doesn’t work that way. So, Veronica there’s nothing to worry about from using skin lotions that contain water.