Dimethicone

The most common silicone in skincare. It forms a silky, smooth film on the skin’s surface and can help to prevent water loss. It also aids in wound healing and can treat and soften scars. Dimethicone is considered to be very safe for use.
Moisturizing
Other functions
Origin
Dimethicone

Overview

Dimethicone is the most common silicone polymer found in skincare, and for good reason.

It is an excellent occlusive and emollient ingredient that does not react with the skin in any way. It seals in moisture and forms a protective film on the skin’s surface. This film is silky and very smooth, which is why this ingredient is a favorite for makeup foundations and primers.

Dimethicone is a white liquid that varies in thickness and is made synthetically by the polymerization of siloxane units. It sits on the skin’s surface and is remarkably stable, inert, hypoallergenic, and non-reactive. It provides occlusive moisturization, prevents water from evaporating, and smooths out micro-cracks in the surface layer of the skin.

Studies have shown that dimethicone does not penetrate into the skin at all and does not even interact with the skin’s lipid matrix. It is therefore very safe to use during pregnancy.

Clinical studies also show us that dimethicone is a widely used ingredient in surgery and post-surgery treatment. This is because dimethicone gels form a protective film over the surgical wound, aiding in the healing process, preventing infections, and preventing the scar from healing incorrectly.

It is also a common ingredient in anti-acne products, although not for the reason you may think. It actually has no anti-acne effects but is rather used for its pleasant feel on the skin and good occlusive properties, which help with the tolerability of any harsh anti-acne actives that may be present in the formulation.

Silicone polymers are a massive group of compounds with one thing in common – the long polymer chain is predominantly made of silicon atoms.

Dimethicone is just one of many other silicone polymers used in skincare. Examples of others include Methicone, Amodimethicone, Simethicone, or Cyclomethicone. Although they may differ in chemical structure, viscosity, and after-feel, they are very similar in all other aspects, and there are no real differences in how they are used.

Science

1
Nair, B., & Cosmetic Ingredients Review Expert Panel (2003). Final report on the safety assessment of stearoxy dimethicone, dimethicone, methicone, amino bispropyl dimethicone, aminopropyl dimethicone, amodimethicone, amodimethicone hydroxystearate, behenoxy dimethicone, C24-28 alkyl methicone, C30-45 alkyl methicone, C30-45 alkyl dimethicone, cetearyl methicone, cetyl dimethicone, dimethoxysilyl ethylenediaminopropyl dimethicone, hexyl methicone, hydroxypropyldimethicone, stearamidopropyl dimethicone, stearyl dimethicone, stearyl methicone, and vinyldimethicone. International journal of toxicology, 22 Suppl 2, 11–35.
2
CARTER, B. N., 2nd, & SHERMAN, R. T. (1957). Dimethicone (silicone) skin protection in surgical patients. A.M.A. archives of surgery, 75(1), 116–117.
3
Ingram, R. J., Bartlett, A., Brown, M. B., Marriott, C., & Whiffield, R. J. (2002). Dimethicone barrier cream prevents infection of human skin by schistosome cercariae: evidence from Franz cell studies. The Journal of parasitology, 88(2), 399–402.
4
Del Rosso J. Q. (2005). The role of the vehicle in combination acne therapy. Cutis, 76(2 Suppl), 15–18.