The Truth About Dimethicone

So, what is dimethicone exactly? 

Dimethicone (polydimethylsiloxane) is a man-made silicone oil found in skin and hair care products that’s used as a moisturizer and an emulsifier, which means it prevents other ingredients from separating. It’s a skin protectant known to calm irritation and moisturize. “These properties make it a highly effective additive to skin and hair care products, and it's also used as an emollient to make the surface of the skin more flexible and help the skin retain moisture,” says Hadley King, MD, an NYC-based dermatologist. 

If you’ve ever used a cream or makeup primer that went on silky smooth, it probably contained the silicone-based polymer dimethicone. Dimethicone is made up of large molecules that can’t be absorbed by your skin. Instead, they sit on the surface and create a barrier to protect against external conditions, like weather, minor skin irritations, and contact dermatitis. “It coats the skin and adds moisture and also helps to seal it in so that the skin can heal faster,” says Dr. King.

What products contain dimethicone?

Many pore-minimizing products, moisturizers for dry skin, serums, lotions, personal care products, and even conditioner contain dimethicone. The popular skincare ingredient is found in a lot of cream-based makeup products as it improves texture, making it easier for products to glide across your skin. It’s also commonly used in makeup primers thanks to its ability to temporarily fill in fine lines and large pores. 

When it comes to hair care products, dimethicone is found in shampoo, conditioner, leave-in conditioner, and detangling products and leaves you with shinier, smoother-looking strands. “Because it acts as an emulsifier, it helps the product coat the hair strands more evenly,” says Dr. King.

Is dimethicone safe?

If you’re worried about dimethicone, you can rest assured that it’s safe for use and carries a stamp of approval from both the FDA and the Cosmetic Ingredient Review. “Side effects are low but allergic reactions, such as redness, swelling and irritation can occur,” says Dr. King. If you are allergic to dimethicone, opt for silicone-free products as an alternative.

What are the pros and cons of dimethicone?

Although dimethicone is a synthetic ingredient, there’s a reason why it’s so common in products: it’s generally safe for use and highly effective. If you have a sensitivity to silicone or simply prefer using natural, silicone-free products, opt for ingredients like jojoba oil, shea butter, or sunflower oil instead.

When it comes to skincare, some claim that dimethicone can clog pores and contribute to breakouts, but there hasn’t been any evidence to back the debate. “Some outlets report it being comedogenic (aka acne forming), but this hasn't been shown to be the case when studied in the lab,” says Caren Campbell, MD, a San Francisco-based dermatologist. 

While dimethicone can help with stubborn tangles by coating the hair shaft, reducing frizz, and increasing shine, it isn’t suitable for all hair types. “For those with oily or fine hair, it can weigh down the hair and make it look greasy,” says Dr. King.

Another common debate surrounding dimethicone is how it impacts the environment. Since it’s a hydrolyzed chemical, it’s washed off with soap and water and can make its way to aquatic environments. It can also wind up in soil, where it’s broken down. “Ultimately, it is degraded to inorganic constituents, carbon dioxide, silicic acid and water,” says Dr. King. “No adverse effects have been detected in experimental organisms representative of the environmental compartments in which dimethicone may be found.”

While we know it’s important to read labels, it can be tough to decode all of the ingredients found in our products. But now that we’ve demystified dimethicone we can appreciate the way this man-made, multitasking ingredient locks in moisture, fills in fine lines, reduces the appearance of pores, and leaves us with smooth, glossy locks. Whether you use a bevvy of products that contain dimethicone or prefer using silicone-free alternatives, now you can make an informed decision next time you’re updating your makeup case.

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