What Is Dimethiconol?
Dimethiconol is a type of silicone that is used in skincare and hair care products. Silicones are a group of synthetic ingredients used to improve the texture and application of skincare, haircare, and cosmetics. Dimethiconol, as a silicone, helps to improve the appearance, texture and feel of the product, prevent moisture loss from the skin, and enhance the efficacy of the product. There has been a lot of controversy over this ingredient, as well as silicones as a broader skincare ingredient group. The controversial claims argue that dimethiconol, 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, the 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 dimethiconol’s safety has produced evidence that not only indicates dimethicone’s safety but also suggests that dimethiconol is beneficial for the skin in many ways.
Dimethiconol, also referred to as silicone gum, is a polymer similar to dimethicone a commonly used silicone in cosmetics. Silicones are synthetic polymers made up of repeating units of siloxane, elemental silicon and oxygen, combined with other elements, most often carbon and hydrogen. Thus, silicones can also be called polysiloxanes. The terms “silicone” and “silicon” are often mistakenly used interchangeably, when they are actually quite different. Silicon is the 14th element on the periodic table and the second most abundant element in the earth’s crust, after oxygen. In contrast, silicones are always synthetically produced.
The good: Help improve the texture and spreadability of skincare and cosmetic products. Like other silicones dimethiconol also acts as a moisturizer, increasing hydration and preventing moisture loss.
The not so good:Can cause some irritation and sensitivity.
Who is it for? All skin types except those that have an identified allergy to it.
Synergetic ingredients: Works well with most ingredients.
Keep an eye on: As dimethiconol forms a protective barrier over the skin make sure to wash off thoroughly, particularly after sweating.
What Are The Benefits of Dimethiconol?
To better understand the functions of dimethiconol, let’s first discuss how silicones function as a class. Silicones have wide spaces between each molecule, which form a molecular lattice. Upon application to the skin, this lattice enables silicones to form a film on the surface while still allowing the skin to “breathe”. Oxygen, nitrogen, and other nutrients can still pass through the protective film formed by silicones. However, most silicones do not allow water to pass through, which is an ideal quality for preventing dry, dehydrated skin.
Silicones improve the feel, appearance, and performance of cosmetic and skincare products. Dimethiconol helps to make formulations feel silky and smooth on the skin. While this is mainly a sensory aspect of the product, dimethiconol also helps the product to apply evenly to the skin. This even application helps the product’s key ingredients to be delivered evenly.
Redness and irritation
Silicones may be able to help with skin redness and irritation due to their low surface tension, which enables them to spread easily across the surface of the skin and form a protective covering. Often irritated and sensitive skin occurs through a damaged skin barrier. The skin barrier is the protective barrier the skin naturally produces with its natural oils. When the skin barrier is compromised it can worsen irritation and sensitivity, this is where silicones like dimethiconol may help by temporarily providing the skin with a protective barrier.
In a similar way to providing the skin with a protective barrier to protect irritated and sensitive skin, dimethiconol prevents moisture loss. As we age or when our skin barrier is not working effectively, the skin loses moisture or water to the air. This is particularly common in dry or air-conditioned environments. This can leave the skin feeling dehydrated and often results in a lackluster appearance. Dimethiconol acts as a conditioning agent thanks to its unique fluidity that makes it easily spreadable, which forms a protective barrier on the skin. It is known for creating a subtle gloss that feels smooth and silky to touch.
Additionally, it helps to fill in lines and wrinkles on the face, giving skin a temporary ‘plump’ appearance. Dimethiconol is known to provide a less greasy feel than standard silicones without sacrificing any of its smoothing properties. As a heavier silicone, it’s often used together with lighter silicones, such as cyclopentasiloxane, that help better deliver it to the skin.
These same conditioning properties make dimethiconol an excellent ingredient for haircare products, like conditioners and leave-in serums. Dimethiconol is thought to offer a controlled conditioning effect to leave unhealthy, damaged hair looking, and feeling more silky and smooth. Additionally, dimethiconol is widely used in hair cuticle coats due to its ability to help with problems such as split-ends.
Is Dimethiconol Safe?
The safety of dimethiconol has been assessed by the Cosmetic Ingredient Review Expert Panel, a group that reviews the safety of skincare and cosmetic ingredients. The Expert Panel evaluated scientific data and concluded that this ingredient was safe for use in cosmetics.
Even though silicones have been proven both safe and effective for cosmetic purposes, many rumors exist claiming they are unsafe for topical use. For instance, there are claims that suggest topically applied silicones can lead to chronic diseases. However, research suggests that it is not possible for topical silicones to cause or worsen disease as their molecules are too large to penetrate the skin, preventing them from entering the bloodstream. Claims that silicones can bioaccumulate or build-up in our bodies is also false since their size prevents them from being able to pass through cell membranes, a key requirement for bioaccumulation.
The large molecular size of silicones also dispels the claim that these ingredients are unsafe for topical use because they are allergens. If a substance cannot penetrate the skin, it cannot react with cells of the immune system. Thus, silicones are not allergens. In fact, silicones are so biologically inert when in contact with the skin, silicones are now replacing latex, a common allergen in adhesives, gloves, and a wide array of other items.
Johnson, W, et al. 2017. ‘Safety Assessment of Dimethiconol and Its Esters and Reaction Products as Used in Cosmetics’, International Journal of Toxicology. 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. D’Souza, P, & Rathi, S, 20105. ‘Shampoo and Conditioners: What a Dermatologist Should Know?’, Indian Journal of Dermatology, vol. 60, is. 3, pp. 248–254.