Probably not, but the evidence is narrower than it looks. Fulton's 1989 rabbit-ear survey reported that simethicone, dimethicone and cyclomethicone did not appear to be a problem, and a 2021 human back-patch study of a dimethicone-containing cream found it non-comedogenic [1][3]. That study was sponsored by the product's maker, and many related silicones were never tested.
Key takeaways
- Fulton reported that simethicone, dimethicone and cyclomethicone did not appear to be a problem in the rabbit ear [1].
- In a 2021 four-week human study, a moisturizer containing dimethicone, glycerin and shea, aloe, cocoa and mango butters scored 0.41 on a 0 to 3 scale. The coconut oil positive control scored 2.09 [3].
- That study was funded by the manufacturer, and all of its authors were company employees [3].
- Dimethicone is a large polymer that is unlikely to be significantly absorbed into the skin, which fits Fulton's idea that ingredients must penetrate the follicle to be comedogenic. That is a hypothesis, not a demonstrated mechanism [1][2].
- Modified silicones, such as cetyl dimethicone, were not covered by Fulton's statement, and the comedogenicity of silicones as a family is not settled by it [1][2].
What is dimethicone?
Dimethicone is a fluid mixture of fully methylated linear siloxane polymers. In cosmetics it acts as a conditioning agent, mostly at concentrations of 15% or less [2]. On a label it appears as Dimethicone.
It belongs to a larger family. The Cosmetic Ingredient Review's 2003 report covers related polymers, including methicone, amodimethicone, cetyl dimethicone, stearyl dimethicone and others [2].
What does the research show?
| Source | Finding |
| Fulton 1989 | Reported that silicones and sterols did not appear to be a problem. The silicones tested were simethicone, dimethicone and cyclomethicone [1] |
| Cosmetic Ingredient Review 2003 | Most dimethicone polymers are used at 15% or less. Dimethicone was a minimal irritant in most rabbit skin studies, was not a sensitizer, and was not absorbed after oral or dermal exposure. The panel considered it unlikely that these polymers are significantly absorbed because of their large molecular weight [2] |
| Gala and colleagues 2021 | In 22 women, a moisturizer containing dimethicone, glycerin and several plant butters had a mean microcomedone grade of 0.41 after four weeks of occluded back patches. Glycerin scored 0.82 and coconut oil 2.09. No adverse events were reported [3] |
The 2021 study is useful because the patches were occluded and the test lasted four weeks. It is also a finished product, so it speaks to the whole formula, not to dimethicone alone. Its sponsor was the maker of the cream [3].
Why might silicones behave differently from esters?
Fulton proposed that for an ingredient to be comedogenic, it must penetrate into the follicle. He also found that large molecular weight esters, such as behenyl erucate and cetyl palmitate, were not a problem [1].
Dimethicone fits that pattern. The Cosmetic Ingredient Review panel judged these polymers unlikely to be significantly absorbed because of their large molecular weight [2]. The idea is plausible, but neither source tests it for dimethicone directly.
What about the worry that it traps oil and dirt?
The concern is common. Consumer health pages note that some people argue dimethicone forms a barrier that seals in oil, sweat and dirt [4]. None of the studies reviewed here tests that claim directly.
The human study offers some indirect evidence. Occluded patches with a dimethicone-containing cream did not raise microcomedones above the glycerin control [3]. That finding applies to the finished cream, not to dimethicone by itself.
What does the evidence not show?
- Modified silicones. Cetyl dimethicone, stearyl dimethicone, amodimethicone and others are different molecules, and the sources reviewed do not report their comedogenicity [1][2].
- Other silicones. Fulton listed three silicones. Cyclopentasiloxane, for example, is not named in his text [1].
- Face data. The 2021 study tested the upper back, not the face [3].
- Independent confirmation. The human data come from one manufacturer-funded study [3].
- A finished product. A 2006 study found that finished products using comedogenic ingredients are not necessarily comedogenic [5]. The reverse also holds: a product's other ingredients still matter.
- A grade. The text of Fulton's survey says silicones did not appear to be a problem, but this article does not assign a number the source does not state [1].
Which silicone names should you check?
| Name on the label | Evidence in the sources reviewed |
| Dimethicone | Covered by Fulton's statement and the 2021 study [1][3] |
| Cyclomethicone | Covered by Fulton's statement [1] |
| Simethicone | Covered by Fulton's statement [1] |
| Cetyl Dimethicone, Stearyl Dimethicone, Amodimethicone | Safety reviewed, comedogenicity not reported [2] |
| Cyclopentasiloxane | Not named in Fulton's text [1] |
What can you do about it?
- Check the whole product. Paste an ingredient list into the Klenzera scanner to see which other ingredients sit alongside the silicone. See How to Read an Ingredient List for Acne-Prone Skin.
- Weigh position. See Does Ingredient Order Matter?.
- Test one product at a time. Use the steps in How to Know If a Product Will Clog Your Pores.
Frequently asked questions
Is dimethicone comedogenic?
Fulton reported that dimethicone did not appear to be a problem in the rabbit ear [1], and a manufacturer-funded human study of a dimethicone-containing cream found it non-comedogenic [3]. The evidence base is small.
Is dimethicone safe?
The Cosmetic Ingredient Review panel concluded that the safety test data support the use of these ingredients at their current concentrations [2]. Safe in that sense is not the same as non-comedogenic.
Does dimethicone trap dirt and oil?
The idea is widely repeated [4], but none of the studies reviewed here tests it.
Are all silicones the same?
No. Fulton tested three silicones. Modified silicones with fatty groups are different molecules [1][2].
When should I see a dermatologist?
If breakouts are painful, cystic, scarring, persistent or suddenly worse, or if you suspect an allergic reaction, talk to a dermatologist or doctor.
The bottom line
Dimethicone has more reassuring evidence than most ingredients in this series, but the evidence is thin, partly manufacturer-funded, and silent on many related silicones. Check the rest of the product too, and let your own skin decide.
This article is for educational and informational purposes only and is not dermatological diagnosis, medical treatment, or clinical advice. Talk to a licensed dermatologist about medical concerns.
Related reading: Comedogenic Ingredients List | Are Comedogenic Ratings Reliable? | Non-Comedogenic vs Oil-Free | Is Lanolin Comedogenic?
References
- Fulton JE Jr. Comedogenicity and irritancy of commonly used ingredients in skin care products. J Soc Cosmet Chem. 1989;40:321-333.
- Final report on the safety assessment of stearoxy dimethicone, dimethicone, methicone, amino bispropyl dimethicone, aminopropyl dimethicone, amodimethicone and related polymers. Int J Toxicol. 2003. doi:10.1080/10915810390204854
- Gala MYN, Muchhala SS, Charugulla SN, et al. Evaluation of comedogenic potential of a paraben-free plant-based butter moisturizing cream: a double-blind, comparative study. CosmoDerma. 2021;1:52. doi:10.25259/CSDM_53_2021. Funded by Dr. Reddy's Laboratories; all authors are employees.
- Healthline. Dimethicone: the good, the bad, and everything else you need to know about this common skin care ingredient. healthline.com/health/beauty-skin-care/dimethicone
- Draelos ZD, DiNardo JC. A re-evaluation of the comedogenicity concept. J Am Acad Dermatol. 2006;54(3):507-512. doi:10.1016/j.jaad.2005.11.1058