What Is Dimethicone?

Dimethicone, also known as polydimethylsiloxane (PDMS), is a silicone oil with special attributes that make it a useful component in many skin and hair care products. It has numerous industrial applications as well, and is even a good additive in some foods. People widely use products that contain the compound, and generally report very few adverse effects, although some individuals do have sensitivities to it.

Use in Personal Care Products

Products such as hair conditioners and shampoos often include dimethicone to facilitate the combing of tangled hair, as well as to give hair a better shine. It forms a slick lubricating coat around each strand of hair so that a comb will move through the hair with significantly less resistance. Also, it acts as a skin protectant and emollient, showing up as an component in many over-the-counter moisturizing lotions and skin creams, as well as in many makeup products. Even diaper rash creams for babies often add this chemical in order to relax the irritated skin.


The U.S. Food and Drug Administration (FDA) has authorized adding PDMS to products such as those listed above, and years of consumer use have shown it to be mostly safe. One area that has brought up concern is the usage of the chemical as a filling for breast implants. For years, PDMS silicone implants were the standard, although recent medical issues have brought on a gradual shift to implants filled with saline.

Expectant and breast-feeding mothers are advised to check with a physician before using any product that has dimethicone. It is possible for a consumer to find out if dimethicone, or one of its variants, is present in a particular product by going over the list of components. Names such as Amodimethicone, Stearoxy Dimethicone and Behenoxy Dimethicone indicate the usage of polymers based on this man-made compound.

Side Effects

A few side effects have been reported from the use of PMDS products; they include gentle itching and stinging or perhaps burning sensations. Allergic reactions such as hives, unexpected breathing difficulties, and swelling in any part of the mouth or face represent can also happen. Users of dimethicone creams may be shocked to find that the product can actually worsen dryness in some individuals. This is not necessarily a sign of ineffectiveness, but may alternatively reveal an allergic reaction that should not be disregarded.

Should such symptoms show up, doctors advise immediately stopping use of the product. Looking for medical assistance is a good idea if the reaction results in being serious, or does not improve quickly. A pharmacist can be another good source for guidance relating to side effects.

Other Uses

Dimethicone is widely used in non-cosmetic products as well. Because of its corrosion-inhibiting qualities, it is a well-known additive in commercial lubricants. Manufacturers of processed foods use the compound to prevent caking and foaming. It is also the primary ingredient in the world-famous toy known as Silly Putty.


Silicon dioxide, commonly referred to as silicon or silica, is a naturally occurring element in the earth. Chemists have efficiently combined silica with oxygen, hydrogen, and carbon. These chemical compounds, which may also include additional elements, are known as silicone polymers, or simply silicones. A polymer is a large molecule that is composed of units of smaller molecules that are repeated in a molecular chain. Not all silicones are identical; they vary depending on how the manufacturer combines and fuses the elements together. To avoid misunderstandings, remember that “silicone” is a product derived from “silicon.”

Physical Characteristics

PMDS is unusual in that it tends to share some of the properties of both a solid and a liquid. Chemists refer to this quality as viscoelastic. At room temperature, a solid mass of the product will at first feel and behave very much like rubber. If left on a solid area over several hours, even so, it will eventually ooze outward to cover the whole area. A person can then peal it off to reveal a perfect mold of the object. This semi-solid state is in part what makes the compound so versatile.