What Is Dimethicone?
Dimethicone or polydimethylsiloxane (PDMS) is a silicone used in skincare, body care, and cosmetic products to help improve the texture and feel of the product, prevent moisture loss from the skin and enhance the efficacy of the product.
Consumers researching dimethicone are often looking for clean but effective skincare. One brand we recommend is Carrot & Stick. Details below.
There has been a lot of controversy over this ingredient, as well as silicones as a broader skincare ingredient. The controversial claims argue that dimethicone, because of its synthetic origin, is bad for the skin, is responsible for acne and breakouts, prevents the key ingredients in products from working, and is bad for the environment.
Due to these claims, responsible regulatory bodies such as the US Food and Drug Administration and the Cosmetic Ingredient Review Expert Panel have invested significant resources into evaluating its safety. The research into dimethicone’s safety has produced evidence that not only indicates dimethicone’s safety but also suggests that dimethicone is beneficial for the skin in many ways.
Dimethicone is a synthetically derived silicon-based polymer or long silicone ingredient. Dimethicone is one of the most widely used ingredients in both cosmetics and personal use products as well as a food additive in cooking oils and kids’ toys.
In 2019, the US Food and Drug Administration recorded 12,934 dimethicone containing products. The most common products that contain dimethicone are; moisturizers, primers, shampoos, conditioners, cleansers and body washes, bath and baby oils, hair dye, and self-tanning products.
Dimethicone is an emulsifier, which means it helps keep the product from separating or splitting. It is also used as a moisturizer helping to prevent moisture loss from the skin and improve the appearance of the skin, giving it that hydrated, plump look. Dimethicone also has many other benefits that derive from these characteristics, see below. Dimethicone is a highly effective additive to skin and hair care products and helps to improve both the product and the appearance of your skin.
Dimethicone
the good: Dimethicone improves the texture of skincare and cosmetic products, helps to improve the appearance of the skin, giving it that plump, hydrated look, and can help to prevent moisture loss.
the not so good: There is a lot of controversy over the safety of this ingredient. Despite this controversy, there are no safety concerns as it is non-irritating, non-toxic, and doesn’t clog the pores.
Who is it for? All skin types except for those with an identified allergy.
Synergetic ingredients: Works well with most ingredients.
Keep an eye on: Nothing to keep an eye on here.
Why Is Dimethicone Used in Skincare?
Dimethicone has several applications in skincare, cosmetics, and body care products. While dimethicone is mainly used to improve the texture and sensory feel of formulations, it has many other benefits to your skin.
Texture
Dimethicone is mainly used to improve the texture of products, helping to give the product a smooth, silky feel. The unique liquid texture of dimethicone allows for the product to be spread smoothly and evenly to the skin.
Dimethicone doesn’t penetrate the skin, sitting on top, protecting the skin, and allowing smooth application. It fills fine lines and wrinkles, helping the skin to appear smoother. This makes dimethicone an excellent ingredient for use in primers as the ability to fill texture and wrinkles improves makeup application. The texture of a product is mostly part of the sensory experience. However, it does also help to deliver the key ingredients of the product evenly to the skin and is useful in a product such as primers.
Hydration and protecting
Dimethicone may help to improve the appearance of dry skin and flakiness. Dimethicone is occlusive, which means that it protects the skin and prevents moisture loss from the top layers of the skin. Moisturise can be lost from the top layers of the skin to the air. Occlusive products help to trap in moisture and can help prevent the progression of skin conditions that occur when the skin barrier is disrupted, such as; eczema, dermatitis, and psoriasis.
The skin barrier is the outer layers of the skin and includes the natural oils that the skin produces. When the skin barrier is damaged or disrupted from hormonal changes, irritation from other products, diet, or inflammation, it can cause the skin to lose moisture, leaving the skin dry and flaky. A healthy skin barrier helps to protect the skin from harmful bacteria and allergens. Dimethicone’s emollient properties can help to soothe the skin and give the appearance of hydration without the greasy residue that other hydrating ingredients leave behind.
Due to the protective and hydrating properties that dimethicone has, it is often included in formulations for mild skin irritations, diaper rashes, and some formulations used to help heal minor wounds and cuts. The dimethicone in these products coats the skin and not only adds moisture to the affected area but also helps to seal moisture in providing a better healing environment for the skin.
Breakouts
Dimethicone may also help to prevent breakouts. There is a lot of misinformation around silicone products and congestive skin types, with many people claiming that they can clog the pores and create an environment that produces breakouts and worsens acne. However, there is no evidence to suggest that this is the case, dimethicone is classified as non-comedogenic and non-acnegenic, meaning that it doesn’t clog the pore or worsen acne. Research has indicated that it helps provide hydration to the skin without the use of heavier hydrating ingredients. Hydration is essential for congested skin types to prevent sebum overproduction and inflammation associated with dryness. Dimethicone also controls shine in oily complexions.
The idea that dimethicone is bad for clogged pores may come from the fact that it is occlusive, meaning that it acts as a protective barrier to the skin. If dimethicone isn’t used correctly and properly cleansed from the skin after exercise or heavy sweating, it is possible to trap sweat between the skin and the dimethicone containing product, potentially causing congestion. Dimethicone containing products may also push other skincare products and ingredients deeper in the skin when they have been used before the dimethicone product. This may also contribute to congested skin as other ingredients may cause irritation and breakouts, mainly when they are pushed deeper into the skin. If you feel that a dimethicone product is congesting your skin, it may be worth looking at your skincare regime as a whole.
Efficacy
Dimethicone may also help to improve the efficacy of the product that it is contained in. As dimethicone may help other ingredients to penetrate deeply into the skin, this can help key ingredients or ‘actives’ to work more effectively.
8 Truths About Dimethicone
There has, in recent years, been a lot of controversy over silicones in skincare, particularly dimethicone. Here are some important truths about dimethicone that you should know before using a dimethicone containing product.
- Natural vs. Synthetic
One of the main criticisms of dimethicone is that it is a synthetic ingredient. There is a stigma around synthetic ingredients in the skincare world, particularly in the green or natural beauty industry. While the idea that natural ingredients are better does seem appealing, it isn’t necessarily true. Many natural ingredients can cause irritation and sensitize the skin and many synthetic ingredients are beneficial and safe for the skin. Dimethicone is one such ingredient.
- Dimethicone and congested skin
Dimethicone has often been accused of clogging pores and worsening congestive skin types. This is because dimethicone is an occlusive ingredient. However, in the extensive research that was reviewed by the Cosmetic Ingredient Review Expert Panel and the US Food and Drug Administration, dimethicone was found to be non-comedogenic and non-sensitizing, meaning that it doesn’t clog pores or cause irritation.
- Key ingredients
Dimethicone has been argued to reduce the ability of the skin to absorb ‘active’ ingredients from skincare products. The opposite has been indicated in the studies conducted to date. Research suggests that dimethicone containing products may actually help key ingredients to penetrate deeply into the skin, allowing them to work more effectively to improve the appearance of the skin.
- Hair loss and dimethicone
Another myth about dimethicone is that when included in hair care products, it prevents the follicle from obtaining oxygen, resulting in hair loss. Again, this is a myth where the truth is the opposite. Silicone products help to coat and smooth the hair follicle, giving it a shiny appearance and making it easier to comb through. When the hair follicle is covered in dimethicone, it is less prone to friction and there less likely to be affected by breakage from styling or combing.
- Environment
An essential area of skincare that has come to the forefront in recent years is the impact that the industry has on the environment. Dimethicone and silicones more generally have been criticized in this area because they are not biodegradable. While this is true, silicone and dimethicone are filtered out of the water as the clay can trap the undissolved ingredients. Clay filtration of dimethicone and silicones degrades the silicone and is a natural chemical-free way to prevent silicones from entering the environment.
- Allergies and irritation
Allergies and irritation have often been linked with silicones and dimethicone. There is no scientific evidence to support this claim. While there are a handful of anecdotal cases of irritation to dimethicone, it is more likely, given the lack of actual evidence, that these cases are reacting to other ingredients in the dimethicone containing products. Dimethicone is too large to penetrate the skin to produce an allergy or irritation.
- Safety
The safety of dimethicone has come under question with claims that it is toxic and accumulates in the body. Dimethicone has undergone extensive study across many countries’ regulatory authorities. In the US, the Cosmetic Ingredient Review Expert panel reviewed the available safety data and determined that dimethicone is safe for its indicated uses. This outcome has been echoed by the US Food and Drug Administration, the EU’s Inventory of Cosmetic Ingredients group, and the World Health Organisation. In the US, the concentration of topical dimethicone containing products is restricted to 30%, and the World Health Organisation recommends that the oral consumption of dimethicone should be limited to 1.5mg/kg body weight. These guidelines are well below the concentration or dosage that has produced an adverse effect during research.
What Are Silicones?
Silicones are a skincare ingredient used to improve the texture and the appearance of your skin. There are a few things that are useful to know about silicones when investigating why they’re in your skincare products. Silicones are organosiloxanes, which means that they are a molecule that has alternating silicone and oxygen atoms along a carbon chain or ring—silicones where originally sourced from sand in the form of silicon dioxide.
There are three main categories of silicones that are used in cosmetic and skincare products. The first is small silicones, the second is silicone polymers or long-chain silicone molecules, and functional silicones which are characterized by their shape and structure. Most silicones can be identified by the end of their name. If an ingredient ends in -cone, -siloxane or -conol, then it is probably a silicone.
Small silicones
Small silicones are liquid and tend to evaporate from the skin. This makes them great for delivering key ingredients to the skin. However, they don’t have the same moisturizing abilities as some silicones. An example of small silicones is cyclohexasiloxane.
Silicone polymers
Silicone polymers are long-chain molecules and can be either liquid or solid; dimethicone is a silicone polymer.
Functional silicones
Functional silicones usually contain other atoms outside of the oxygen, carbon, and silicon that is found in the other forms of silicone. These other atoms give them a different structure and tend to inform their properties. An example of functional silicones is dimethiconol.
Other Uses:
Dimethicone is an ingredient that is often used in kid’s toys. It is usually included in products like Kinetic Sand, Putty, and slimes. Dimethicone is also used in adhesives, sealants, and water repellents.
References:
Carter, B & Sherman, R, 1957. ‘Dimethicone (Silicone) Skin Protection in Surgical Patients’, Archives of Surgery, vol. 75, is. 1, pp. 116-117.
Cosmetic Ingredient Review, 2019. ‘Safety Assessment of Dimethicone, Methicone and Substituted-Methicone Polymers, as Used in Cosmetics’, Cosmetic Ingredient Review Expert Panel.
De Paepe, K, 2014. ‘Silicones as nonocclusive topical agents’, Skin Pharmacology and Physiology, vol. 27, pp. 164-171.
Kwon, S, et al., 2013. ‘The effect of glycerin, hyaluronic acid and silicone oil on the hydration, moisturization and transepidermal water loss in human skin’, Korean Journal of Aesthetic Cosmetology, vol. 11, pp. 761-768.
Mojsiewicz-Pieńkowska, K et al., 2016. ‘Direct human contact with siloxanes (silicones)- safety or risk: Part 1 Characteristics of siloxanes (silicones), Frontiers in Pharmacology, vol. 7, pp. 132.
Pellicoro, C, Marsella, R, & Ahrens, K, 2013. ‘Pilot study to evaluate the effect of topical dimethicone on clinical signs and skin barrier function in dogs with naturally occurring atopic dermatitis’, Veterinary medicine international.
Yahagi, K, 1992. ‘Silicones as conditioning agents in shampoos’, Journal of the Society of Cosmetic Chemists, vol. 43, pp. 275-284.
