Dimethicone for Skin: A Rousing Defense

Medically reviewed by Anna H Chacon, M.D. FAAD
Dimethicone for Skin: A Rousing Defense

You may have heard already - we’ve released a brand new product called Water Lock, and its star ingredient is dimethicone, one of the most popular silicones used in skincare. 

This has raised questions from some of our friends and customers - is dimethicone safe? What about comedogenicity? Doesn’t silicone block your skin from breathing or something?

There’s a lot of confusion and misinformation when it comes to this frankly incredible ingredient. In this post, we’ll bust some myths and explain why dimethicone is such a skincare superstar. 

If it wasn’t, rest assured we wouldn’t be using it in our products!

    What is dimethicone?

    Dimethicone is a type of silicone, which is a class of skincare ingredients derived from crystalline silica, one of nature’s most abundant materials. It's a very fluid silicone made up of long chains of silicon and oxygen atoms in a linear formation. It’s sometimes also called polydimethylsiloxane. 

    What makes dimethicone so interesting in skincare is that it behaves differently depending on factors like temperature and how it’s formulated. These small changes can alter how it sits on the skin, which changes its cosmetic properties.

    What is dimethicone used for in skincare?

    In the US, dimethicone is actually considered a drug ingredient, and products made with it can be classified as OTC skin-protectant topical drugs. It’s also used in other types of medications, including ones that can be ingested. 

    It’s incredibly valuable in skincare formulas because it has an exceptionally pleasant skin feel and the ability to create a partial barrier over the skin that prevents moisture loss. It’s also a very safe, gentle, and non-comedogenic ingredient. It works well across all skin types and it doesn’t aggravate any sensitivities or concerns. 

    In other words, for cosmetic chemists who want to create an effective, pleasant, and safe moisturizer, dimethicone is a no-brainer.   

    Dimethicone skin benefits

    While dimethicone may not be a sexy skin renewing active like some of our favorite heavy-hitters (namely retinol, vitamin C, and AHA), it still offers some profound benefits that make it incredibly useful in formulas like Water Lock.  

  • It’s a skin protectant: Dimethicone is insoluble in water, so it stays put well even when rinsed. This is why it’s such a popular ingredient in waterproof makeup, but this also makes it valuable as a skin protectant against irritating external forces. For decades now, it’s been used in medical settings to protect barrier-disrupted skin.  
  • Scar reducer: Silicone sheets and gels both show promising scar reduction ability, especially when it comes to slightly raised scars which are notoriously tough to treat. There’s some debate as to why silicones are able to do this, but experts theorize it may have to do with how silicones occlude and protect the skin, or to do with their ability to improve cell proliferation. 
  • Prevents transepidermal water loss: Multiple studies show that dimethicone and other silicones when formulated correctly, are able to keep the skin hydrated by preventing transepidermal water loss (TEWL). Depending on the research, you’ll see different rates of TEWL decrease. That’s because dimethicone’s occlusive (i.e., moisture-sealing) capacities change based on how it’s formulated. When creating Water Lock, our focus was on optimizing its hydrating effects by adding other hydrating and moisture-sealing ingredients. 
  • Immediate skin smoothing: Dimethicone is considered an “astringent emollient” which means it smooths down dry or flaky skin and imparts a silky feel, but it’s also kind of dry and non-oily. It makes the skin look and feel immediately better, while also keeping it moisturized in the long term. 
  • How does dimethicone work?

    We’re actually not totally sure. 

    Most professionals believe that dimethicone helps the skin by creating that slightly permeable occlusive barrier. The skin can repair itself better when it’s able to retain moisture.

    But another theory suggests that dimethicone, at least in certain formulations, is able to improve cell proliferation, which is how it promotes healing and prevents TEWL over time. 

    We think that it’s a little bit of both. Dimethicone’s moisture-locking abilities depend on how it’s formulated, but it always has the ability to improve overall cell function to aid in skin healing and scar reduction. 

    Is dimethicone safe in skincare?

    Yes! Dimethicone has been thoroughly vetted by multiple organizations, and there’s an overwhelming amount of data to prove its safety on a range of fronts. According to the Cosmetic Ingredient Review, which is the body that instructs the FDA on ingredient safety, it’s incredibly safe when applied to the skin, and it also poses little-to-no risk when ingested or inhaled (although we still don’t recommend you eat Water Lock) 

    Do dermatologists recommend dimethicone

    Dermatologists often recommend products that contain dimethicone, whether as simple moisturizers, as skin protectants or as added ingredients to other topical medications. Dimethicone and other silicones are very popular with dermatologists due to their low likelihood of irritating the skin and their functionality as a skin-protectant.  

    Dimethicone myths busted

    And now we get to the fun part! Here are our answers to the common concerns, questions, and myths that surround dimethicone

    Does it totally occlude the skin?

    Silicones, and especially dimethicone, are often talked about as occlusives. In skincare, an occlusive is an ingredient that seals water into the skin and prevents transepidermal water loss. 

    We know for a fact that dimethicone is effective at preventing transepidermal water loss, but its status as an occlusive is a little more complex. Basically, depending on how it's formulated, dimethicone can behave very differently.

    This makes it a useful base for an adjustable occlusive. On its own, the science suggests that it’s occlusive, but not to a dramatic extent. In some cases, it might not affect TEWL at all. 

    Blending with different silicones and other emollients changes its ability to occlude the skin. So in Water Lock, we mixed it with a few fatty acids, squalane, and beeswax. That said, we also added water and humectants, designed to hydrate the skin a little more directly.  

    There’s also a theory it improves scarring not because it occludes but because it’s cell signaling. 

    If you are after total occlusion, you can also try slugging with a more powerful (albeit greasy) occlusive like petrolatum. 

    Does dimethicone suffocate the skin? 

    Definitely not. To start, the idea that the skin can be “suffocated” doesn’t make much sense - the skin doesn’t breathe! 

    That said, since dimethicone alone is not a total occlusive but an adjustable one means that it can’t be totally impenetrable. 

    Mixing it with other occlusives improves its overall occlusivity while still allowing for a small and healthy amount of moisture evaporation as well as prevention of the sealing of pathogens or bacteria close to the skin. 

    Does dimethicone cause acne? 

    The answer is no, for the most part. Dimethicone is widely considered a non-comedogenic ingredient, and it’s been used in countless products for acne-prone skin, including medicated acne treatments. 

    In fact, it’s possibly its partial (rather than complete) occlusivity that prevents it from being comedogenic. One study showed that prolonged, total occlusion leads to the proliferation of bacteria - in a way, there can be such a thing as too much hydration. 

    Does dimethicone cause cancer? 

    Definitely not. There are a lot of dubious claims that common cosmetic ingredients are carcinogenic, but this claim hasn’t actually been made for dimethicone. 

    Because of its large molecular size, there is absolutely no way for dimethicone to even penetrate into the skin in a way that might contribute to cancer. That said, even when ingested it does not pose a risk. Its safety is well accepted by all major international regulatory bodies.  

    Is it bad for the environment? 

    Dimethicone’s safety for humans is undeniable, but just as importantly, it’s also fine for the environment. 

    This mineral-derived ingredient isn’t easily dissolved, which makes environmentalists worry about whether it’ll accumulate in the environment. While the EU has chosen to restrict the use of some silicones (namely, D4 and D5 and only in wash-off products), no organization has found a bioaccumulation or biotoxicity risk when it comes to products containing dimethicone and other commonly-used cosmetic silicones. Dimethicone may not be easily soluble, but it’s easily filtered from waterways, so you don’t need to feel guilty when using it. 

    The bottom line on dimethicone

    The idea that anything that sounds even remotely like a chemical is dangerous is widespread, but it’s not based on real science - instead, it’s actually based on a fear of science. 

    (Never mind the fact that every substance in existence is a chemical). 

    Fair enough - words like “dimethicone” sound big and unfamiliar, and it’s not always easy to keep track of what’s what. 

    It’s part of the reason why we prefer to use the term “retinal” instead of the full ingredient name, retinaldehyde. It’s a perfectly safe, naturally-occurring precursor to vitamin A that makes the skin look oh so smooth, but unfortunately, it also sounds suspiciously similar to formaldehyde. 

    But digressions aside, in the case of dimethicone and other silicones, the concerns couldn’t be more baseless. Rather than irritating or breaking out the skin, this ingredient is the perfect permeable protector. 

    It’s adjustable, with a phenomenal ability to prevent just the right level of transepidermal water loss, for optimal skin hydration. Not to mention that it’s remarkably effective at smoothing down scars. 

    If your skin is dehydration-prone, there is absolutely no reason to avoid dimethicone - quite the opposite! Your skin might thrive with this silky, adjustable emollient.

    If you’d like to introduce some of that hydrating magic into your routine, have a look at Water Lock. 

    It combines dimethicone with other light, pleasant occlusives, like squalane, beeswax, and a blend of multi-weight polymers. Plus, it also includes water, glycerin, and hyaluronic acid to promote additional water absorption.  

    Day or night, it’s the ideal occlusive for nearly any skin type, and thanks to dimethicone, it also has the most incredible lightweight, non-greasy texture.

    Medically reviewed by Anna H Chacon, M.D. FAAD

    Try a Retinol with Guaranteed Results

    Is your retinol not yellow?

    That's the first...yellow flag that your retinol may not be formulated properly. Real retinol––like it's cousin beta carotene that makes carrots bright orange––should be bright yellow.