One of the most common cosmetic ingredients worldwide, found in 20,055 products in our database. CIR has concluded Dimethicone is safe as used at current concentrations and practices. This silicone-based emollient forms a low-permeability hydrophobic film on the skin, improving texture and reducing moisture loss. Despite ongoing consumer debate about silicones in skincare, the safety data for Dimethicone is extensive and reassuring — though environmental persistence remains a separate area of discussion.
Dimethicone is a polydimethylsiloxane (PDMS) — a silicone-based polymer composed of repeating units of dimethylsiloxane. It is one of the most widely used cosmetic ingredients globally, appearing in products ranging from moisturisers and primers to shampoos, conditioners, and colour cosmetics. Its popularity stems from its unique sensory properties: it imparts a smooth, silky feel to formulations without greasiness, and it forms a breathable film on the skin that helps reduce transepidermal water loss (TEWL).
Physically, Dimethicone is a clear, colourless, odourless liquid available in a wide range of viscosities — from thin, easily spreadable fluids to thick, high-viscosity forms. This versatility allows formulators to select the grade that best suits their product type. Lower-viscosity grades spread easily and feel lightweight, while higher-viscosity grades provide more substantial occlusion and longer-lasting barrier properties. Dimethicone is chemically inert, thermally stable, and resistant to oxidation, which contributes to product stability.
CIR has reviewed Dimethicone and related silicone compounds multiple times and concluded that Dimethicone is “Safe as Used” at current concentrations and practices, though data on certain inhalation-type use scenarios is limited. It is not absorbed through the skin in meaningful amounts — the polymer molecules are too large for significant percutaneous penetration. There are no EU restrictions on its use in cosmetics, no notable harmonised health hazard classifications for general dermal use, and no allergen flags. Note that Dimethicone (a high-molecular-weight linear polymer) should be distinguished from D4/D5 cyclic volatile siloxanes, which face separate environmental and regulatory scrutiny. The ingredient has a long track record of safe use across all product categories and skin types.
Forms a low-permeability but not fully occlusive hydrophobic film on the skin surface that reduces transepidermal water loss (TEWL). Unlike heavy occlusives, this film reduces TEWL without the heavy occlusive feel of some other barrier agents, helping maintain skin hydration throughout the day. The barrier is not literally “breathable” in a biological sense but is lighter and more permeable than petrolatum-type occlusives.
Gives products an elegant, non-greasy feel that spreads easily on the skin. Dimethicone fills in fine lines and textural irregularities, creating a smooth canvas — which is why it is a staple in makeup primers and foundations.
Smooths rough, dry skin and improves the appearance of fine lines by creating an even surface. Acts as an emollient that softens and conditions without heaviness, leaving skin feeling supple and comfortable.
Generally considered unlikely to cause acne, with low irritation and sensitisation risk. Dermatological testing supports its suitability for sensitive and reactive skin types, though final reactions depend on the overall formulation and individual skin. Its chemical inertness means it rarely causes adverse reactions.
Suitable for: All skin types including sensitive and acne-prone. Dimethicone is generally considered unlikely to clog pores and is frequently recommended by dermatologists for patients with reactive or easily irritated skin, though individual responses may vary depending on the overall formulation.
Dimethicone receives a very low risk rating of 2/10. CIR has reviewed it and concluded “Safe as Used” at current concentrations and practices, though data on certain inhalation-type use scenarios is limited. There are no notable harmonised health hazard classifications for general dermal use, no allergen flags, and no EU regulatory restrictions. It is generally considered to have low irritation and sensitisation potential and is not absorbed through the skin in meaningful amounts. The extensive safety record and absence of regulatory concerns for dermal use support this low rating.
Dimethicone is generally considered unlikely to clog pores. One of the most persistent myths about silicones is that they clog pores and suffocate the skin. Dermatological testing supports Dimethicone’s non-comedogenic profile. Dimethicone forms a low-permeability but not fully occlusive hydrophobic film that reduces TEWL without the heavy occlusive feel of some other barrier agents. It is not literally “breathable” in a biological sense, but its molecular structure creates a more permeable layer than petrolatum-type occlusives. Final reactions depend on the overall formulation and individual skin.
The “buildup” concern is manageable. Some consumers worry about silicone buildup on the skin or hair over time. While Dimethicone can accumulate with repeated use (particularly in hair care), this is easily addressed with regular cleansing. A standard cleanser or occasional clarifying shampoo removes accumulated silicone effectively. Buildup is a maintenance consideration, not a safety concern.
Environmental persistence is a separate question from skin safety. Dimethicone is a high-molecular-weight linear polymer (PDMS) that is persistent in the environment and does not readily biodegrade. However, it is important to distinguish Dimethicone from D4 (Cyclotetrasiloxane) and D5 (Cyclopentasiloxane), which are volatile cyclic siloxanes with PBT/vPvB (persistent, bioaccumulative, toxic / very persistent, very bioaccumulative) concerns and face specific EU regulatory restrictions. The environmental profile of high-MW PDMS is different from these low-MW cyclic compounds. Regardless, environmental persistence does not affect the dermatological safety profile — the two issues should be evaluated independently.
As a topically applied cosmetic ingredient with expected minimal systemic absorption, Dimethicone is generally considered low-risk during pregnancy. CIR has found it safe as used at current concentrations and practices. The polymer molecules remain on the skin surface and are not absorbed in meaningful amounts. No common regulatory warnings advise against its use during pregnancy or nursing. If you have specific concerns, consult your healthcare provider for personalised guidance.
Dimethicone is an emollient that works as part of your formulation. Simply use your product as directed — the silicone functions seamlessly within the product to improve texture, spreadability, and skin feel without requiring any special technique.
Apply water-based products (toners, essences, water-based serums) before silicone-based products. Dimethicone forms a film on the skin that can impede the absorption of water-based products applied afterwards. Following the “water before silicone” rule ensures all your products penetrate effectively.
Regular cleansing prevents potential silicone buildup on the skin. A standard cleanser is sufficient for daily removal. If you use multiple silicone-heavy products, double cleansing (oil-based cleanser followed by water-based cleanser) can ensure thorough removal.
Dimethicone is a cornerstone of makeup primers. It fills fine lines and pores, creating a smooth base that helps makeup apply evenly and last longer.
Used as an emollient base in moisturisers and creams. Provides a non-greasy, lightweight protective layer that helps lock in hydration without heaviness.
Smooths the hair cuticle, reduces frizz, and adds shine. Found in conditioners, serums, and leave-in treatments for manageable, glossy hair.
Apply Hyaluronic Acid first to draw moisture into the skin, then layer Dimethicone-containing products on top to seal in that hydration. The silicone barrier helps prevent the moisture from evaporating.
Niacinamide (Vitamin B3) pairs well with Dimethicone. Apply your niacinamide serum first, then follow with a silicone-containing moisturiser or primer for a smooth, balanced finish.
Dimethicone can help buffer the irritation potential of retinol. The silicone film creates a gentle barrier that may reduce the harshness of retinoid products, making them more tolerable for sensitive skin.
Layering multiple silicone-heavy products can cause pilling — small balls of product rolling off the skin during application. If you experience pilling, reduce the number of silicone-based layers or allow each layer to absorb fully before applying the next.
Combining Dimethicone-based products with heavy facial oils may feel excessively occlusive or heavy on the skin. If you use both, apply the oil first and the silicone product on top, or choose one or the other for a given routine.
Apply your Vitamin C serum first and allow it to fully absorb before applying silicone-containing products. The Dimethicone film can impede the penetration of water-soluble actives like ascorbic acid if applied beforehand.
Found in 20,055 products in our database — one of the most widely used cosmetic ingredients. Here are some examples:
Scan your skincare products and instantly see ingredient details with SkinSenseDiary.
Download the App