Cyclopentasiloxane

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

Also functions as a solvent to dissolve and deliver ingredients to skin

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 categorized 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.

See: Silicone, Cyclomethicone