Silicone in skincare: is dimethicone harmful?
Arin Editorial · how this is made
You've seen it on the labels of creams, foundations, and shampoos. When you spot 'dimethicone,' you might have heard someone say it's 'like plastic on your skin.' Here's what the ingredient actually is and what we know about its safety.
What is it?
Dimethicone is a synthetic silicone polymer. It's a large molecule made of repeating units, commonly called silicone oil. It is produced by treating dimethyldichlorosilane with water. When applied to skin, it forms a thin, slippery film that helps products spread smoothly and leaves a silky feel.
What does it do?
It has several roles. As an emollient, it creates a protective layer on skin and hair. As a skin protectant, the U.S. Food and Drug Administration (FDA) has approved it at 1-30%. It is also an anti-foaming agent, used as food additive E900. In conditioners, it coats the hair shaft, smoothing the cuticle and reducing friction. Less friction means less breakage, which is a common reason for hair loss.
What do safety reviews say?
The Cosmetic Ingredient Review (CIR) Expert Panel concluded in 2021 that dimethicone and 29 related polymers are safe in cosmetics as currently used, provided they are formulated to be non-irritating. The only exception was products that could be incidentally inhaled, such as sprays and airbrush formulations, where data were insufficient. The FDA allows dimethicone as a skin protectant at 1-30%. In 2020, the European Food Safety Authority (EFSA) reviewed PDMS as a food additive and found no safety concerns, though it recommended a limit for certain cyclic siloxane impurities left over from manufacturing.
Are the internet claims true?
Posts claiming dimethicone is toxic, accumulates in the liver, or causes tumors circulate online. They are not backed by scientific studies. Comprehensive reviews by bodies like CIR found no evidence to support these claims. Genetic damage tests are conflicting: some show an effect, others don't. That alone is not enough to call it carcinogenic. The hair loss claim is also unsupported. Silicones coat the hair and reduce friction, which may actually prevent breakage. However, some people may experience clogged pores or breakouts. That's a tolerance issue, not toxicity.
CIR and FDA find it safe for current uses; more data are requested for inhalable forms.
Don't panic. Dimethicone is a widely tested and generally safe ingredient. For breathing concerns, be cautious with spray products; hold your breath, or use a brush or sponge instead of an airbrush. If you're prone to acne, test on a small area first. If you react, stop using it. If you simply dislike the slippery feel, choosing products without dimethicone is your call.
Sources
- Cosmetic Ingredient Review (CIR) safety assessment, 2021
- FDA OTC skin protectant monograph (via cosmeticsinfo.org)
- EFSA 2020 re-evaluation of PDMS (E900)
- cosmeticsinfo.org: Dimethicone, Methicone and Substituted-Methicone Polymer Ingredients