Cyclopentasiloxane at a glance

  • Enhances the silky-smooth spreadabilty and sensorial feel of a product
  • Promotes even distribution other ingredients in a formula
  • Quickly evaporates from skin’s surface without leaving a heavy feel
  • Popular in a wide range of skin and hair care products
  • Compatible with other organic molecular ingredients
  • Also functions as a solvent to dissolve and deliver ingredients to skin

Cyclopentasiloxane description

Cyclopentasiloxane is often included in skin care formulations to improve the silky-smooth spreadabilty and sensorial feel of a product. It is a lightweight silicone, whose appearance as a raw material is a clear, odorless fluid. Cyclopentasiloxane also functions as a solvent to help improve the dispersion of cosmetic ingredients in a solution and improve delivery of key ingredients. Cyclopentasiloxane is categorise as a volatile silicone, but it’s important to distinguish that the word volatile here doesn’t mean irritating to skin. Instead, it means this kind of silicone evaporates quickly from skin’s surface, which is one of the advantages of formulating with cyclopentasiloxane as it is able to evenly distribute other key ingredients without leaving a heavy or occlusive feel. It also means you don’t have to worry about cyclopentasiloxane “trapping” or “congesting” skin (as is also true for other silicones). The velvety film left behind is permeable, meaning this siloxane doesn’t suffocate skin. Cyclopentasiloxane also shows up in hair care formulas (particularly conditioners and hair serums) where it lends a softening + smoothing feel and makes hair remarkably shiny. While cyclopentasiloxane is typically the name that you’ll see on a product’s ingredient list, it also goes by cyclomethicone D5 or just D5 in research literature. According to the Cosmetic Ingredient Review Expert Panel’s assessment (as reported in 2011), cyclopentasiloxane can safely be used in up to 93% in personal care products. It does not pose a health risk to skin as used in cosmetic products.

Cyclopentasiloxane references

  •, Accessed May 2021, ePublication
  • Regulatory Toxicology and Pharmacology, February 2016, pages S67-S76
  • Environmental International, November 2015, pages 55-63
  • International Journal of Toxicology, December 2011, pages 149-227

Peer-reviewed, substantiated scientific research is used to assess ingredients in this dictionary. Regulations regarding constraints, permitted concentration levels and availability vary by country and region.

Ingredient ratings


Proven and supported by independent studies. Outstanding active ingredient for most skin types or concerns.


Necessary to improve a formula's texture, stability, or penetration.


Generally non-irritating but may have aesthetic, stability, or other issues that limit its usefulness.


There is a likelihood of irritation. Risk increases when combined with other problematic ingredients.


May cause irritation, inflammation, dryness, etc. May offer benefit in some capability but overall, proven to do more harm than good.


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Not rated

We have not yet rated this ingredient because we have not had a chance to review the research on it.