Is the Skin a Sponge or Not?

some analogies are better absorbed than others

Hello!

Hope you’ve all been well. I am coming out of the busiest two months of my professional career thus far and while it feels good, I’ve missed you dearly. My Google Drive is bursting with drafts and my Notes App filled with sentence fragments about sunscreen and acne. 

I also have some very exciting news to share about one of my all-time favorite brands, Sachi Skin. I talk about Sachi Skin constantly, but in case you’re new here: based out of Singapore and the UK, Sachi blends Ayurvedic medicine with advanced ingredient technology to make powerhouse products with diverse skin states and tones in mind. Their Pro-Resilience Serum does exactly what it sounds like (makes your skin stronger, healthier and more resilient) and can be used under LED. Their Triphala Pigmentation Corrector is, in my opinion, the best pigment product on the market and helps with everything from post-acne red marks to melasma, without acids, retinoids or hydroquinone. My favorite exfoliant of all-time, ever, period, is their Complexion Clarifying Accelerator. Finally, their Ursolic Acid & Retinal Overnight Reform is the only retinoid I’ve considered swapping out my Tretinoin for. Am I piquing your interest? Great! Because as of last week, the studio where I work, Ställe Studios in NYC, is the only retailer of Sachi Skin in the United States!!!!!!! I’ve been working on this for months and I am simply so excited to make it easier for people to access the brand. We ship nationwide and for just two weeks, you can use HOTLINESACHI15 for 15% off your order. 

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I’ve been told to apply hyaluronic acid to damp skin to help it absorb better because the skin is like a sponge. But recently I’ve seen people on social media say that the skin is not like a sponge and that is a myth. What’s true? How am I supposed to apply these products?

This is a great question! No, the skin is not like a sponge, but there are characteristics of sponges that can help us understand certain things in the skin. 

Everyone knows what a sponge is and can visualize how to use one. A dry sponge doesn’t do much, but once it absorbs water and dampens, it’s more malleable and pliable. It’s able to hold onto things (water, dish soap, food particles) and do its thing as a sponge. Also think of a damp vs. dry beauty blender. 

The skin is not like a sponge because we are not made of sponge and the very purpose of our skin is to be a barrier. It’s meant to keep the good stuff in and the bad stuff out. If it was that easy for say, water, to pass through our skin, as it does in a sponge, we’d drown in the shower and every time it rains. If the skin were a sponge, we wouldn’t have evolved very far. However, damp skin does exhibit some behavior that dry skin does not and a sponge is a helpful analogy to demonstrate this. It is not the same thing as saying the skin is a sponge.

Remember that the skin barrier is composed of many layers of dead skin cells and lipids. This is where the majority of your skincare products are working. In deeper layers you’ll find blood vessels, collagen, elastin and fat. These layers have different requirements to allow things to pass. Among other things, the molecule needs to be the right size (small) and solubility – some molecules are water soluble, whereas others are oil soluble, and we know those two don’t mix! Unlike wetting a sponge, applying something on your skin does not mean it just gets to pass through all the little holes. We also don’t always want it to because…skincare is for the skin! 

When skin is damp, it increases the permeability by thinning the lipids holding our barrier together. This means that things that should be able to go a little deeper are able to more easily (if they are properly formulated, of course). This is good because hydration doesn’t just sit on the surface, but permeability is not the same as absorption. A little deeper doesn’t mean all the way to the bloodstream. 

Like you said, you’ve been told to apply hyaluronic acid on damp skin to help it absorb. Hyaluronic acid is a humectant – a type of ingredient that attracts and retains water. Humectants sitting on the surface can’t do much for us, so applying them on damp skin makes it easier for them to travel a bit deeper. The opposite is true for active ingredients, like retinoids and acids, which you want to apply on dry skin since increased permeability can make them more irritating. 

The reason you’ve been hearing people say the “skin is a sponge” is a bad analogy is because it easily lends itself to misinformation about product absorption, particularly into the bloodstream. This is a big idea pushed by the clean beauty industry and often follows the common myth that your skin absorbs 60% of what you apply. There will be no fear mongering about ingredients here! It’s hard enough for molecules to get past the surface of the skin, let alone all the way to the bloodstream. There are, of course, ways to make it so ingredients can travel further, but that’s thanks to advanced formulations, not a function of the skin. 

To sum it up: if the sponge analogy helps you to understand this very specific property of skin, then great! But don’t take it literally. Your skin is a barrier and if you’ve made it this far, it’s doing a pretty dang good job.