Silicones in skincare and hair care: good, bad or overhyped?

Silicones are not bad for most people. Ingredients like dimethicone smooth hair, reduce frizz and help skin hold on to water, and they are rarely irritating. The real trade-offs are buildup on hair, a heavy feel for some skin types and, for cyclic silicones such as cyclopentasiloxane, persistence in the environment, which is why the EU restricts them.

What are silicones in cosmetics?

Silicones are synthetic ingredients built on a backbone of silicon and oxygen. In cosmetics they form a thin, flexible film on skin or hair. That film makes creams spread easily, makes foundation and primers feel silky, adds shine and slip to hair and reduces how much water evaporates from the skin.

You can usually spot them by their endings: -cone, -conol, -silane or -siloxane. Here are the ones you'll see most:

Are silicones bad for hair?

Silicones are among the most effective ingredients for making hair feel smooth. They coat the hair surface, reduce friction when you comb, tame frizz and add shine. They can't repair a damaged hair fiber, but they make it look and behave better.

The downside is buildup. Non-water-soluble silicones can accumulate if you use several silicone products and only wash with a very mild shampoo. Hair may then feel heavy, flat or greasy faster, especially if it is fine. A regular shampoo usually removes them; a clarifying wash every week or two helps if you use a lot of styling products.

• Fine or oily hair: lighter, rinse-off formulas or silicone-free products may feel better.
• Thick, curly, dry or bleached hair: silicones in conditioners and leave-ins often help with tangles and frizz.
• Sulfate-free shampoo users: watch for buildup and clarify occasionally. Our guide to sulfates in shampoo explains the trade-offs.

Dimethicone in skincare: is it safe?

Dimethicone is one of the most widely used skincare ingredients. It forms a protective film that reduces water loss and can shield the skin from irritants. Because its molecules are large, it is not expected to be absorbed into the skin in any significant amount, and the US Cosmetic Ingredient Review panel has concluded it is safe as used in cosmetics. In the US it is also used as the active ingredient in some over-the-counter skin protectant products.

Allergic reactions to dimethicone are uncommon, which is one reason it appears in many products for sensitive skin. Some people simply dislike the slippery feel or find rich silicone formulas too heavy, which is a texture issue rather than a safety one.

Do silicones clog pores?

Dimethicone is generally considered non-comedogenic, meaning it has a low risk of blocking pores, and it is common in products made for oily and acne-prone skin. The film it forms is thin and does not seal the skin like a plastic wrap.

If you break out after a new product, the cause is more often a combination of heavy oils, waxes or the overall formula than the silicone itself. Still, everyone's skin is different: if a product keeps causing breakouts, stop using it and compare its ingredient list with products that suit you. Our guide on acne causes and what helps covers the bigger picture.

Cyclopentasiloxane and the environment: why the EU restricts it

The main concern with silicones is not your skin but the environment. Cyclic silicones, known as D4, D5 and D6, break down very slowly and can build up in living organisms, which led EU regulators to classify them as very persistent and very bioaccumulative. Because a lot of what we apply is eventually washed down the drain, cosmetics are a major source of these substances in the environment.

• D4 (cyclotetrasiloxane) is prohibited in EU cosmetics because it is classified as toxic to reproduction.
• D5 (cyclopentasiloxane) has been limited to 0.1% in EU rinse-off products, such as shampoos and shower gels, since 2020.
• D5 and D6 will also be limited to 0.1% in leave-on cosmetics, such as creams and makeup, from June 2027, under a 2024 EU restriction.

On the human safety side, the EU's Scientific Committee on Consumer Safety considers D5 safe at the concentrations used in cosmetics, except in hair styling aerosols and sun care sprays, where it could be inhaled. D4 has been studied for possible effects on hormones. Linear silicones like dimethicone are not covered by these restrictions.

How Green Point flags silicones

Green Point classifies these ingredients as Silicone and rates them cautiously, so a product can lose points for containing them. Cyclopentasiloxane and cyclomethicone also carry the Suspected endocrine disruptor classification. This is a precautionary approach that weighs environmental persistence and open questions, not a sign that a conditioner with dimethicone will harm your hair or skin.

Want to check other ingredients on the same label? Our guide to reading cosmetic ingredient lists explains INCI names and ingredient order, and our guide to endocrine disruptors in cosmetics explains what "suspected" means.