Cyclopentasiloxane
SY-klo-PEN-tuh-sil-OX-ane
What Is Cyclopentasiloxane?
A lightweight, volatile cyclic silicone that evaporates from the hair after application. It provides temporary smoothing and acts as a carrier for other conditioning ingredients.
Source: Synthetic silicone compound
Origin: Synthetic
Also known as: D5, Cyclomethicone
What Does Cyclopentasiloxane Do to Your Hair?
Delivers instant slip and spreadability to hair products, then evaporates without leaving residue. Acts as a carrier to deposit other beneficial ingredients evenly on the hair shaft.
Best For
All hair types, fine hair, frizzy hair, heat-styled hair
Not Recommended For
None specifically, though some prefer to avoid all silicones
Concentration Matters
1-10% in hair products
Hair Type Compatibility
Method Compatibility
Safety & Regulation
Generally considered safe. EU has restricted its use in wash-off products above 0.1% due to environmental persistence concerns (bioaccumulation in aquatic environments), not human safety concerns.
FDA Status: Generally Recognized As Safe
FDA permits use. EU has placed environmental restrictions on concentration in wash-off products.
EWG Score: 4/10
HairAide Verdict
A useful lightweight silicone that evaporates cleanly. Environmental concerns in the EU are worth noting, but from a hair performance standpoint it works well for all hair types without buildup.
Products That Contain Cyclopentasiloxane
Heat protectants, serums, conditioners, styling products, hair oils
Alternatives to Cyclopentasiloxane
If you want to avoid Cyclopentasiloxane, look for products with these ingredients instead:
Isododecane, Caprylyl Methicone, lightweight plant oils
Frequently Asked Questions
Yes, Cyclopentasiloxane has a safety rating of 7/10 and is generally considered safe for use in hair products. Generally considered safe. EU has restricted its use in wash-off products above 0.1% due to environmental persistence concerns (bioaccumulation in aquatic environments), not human safety concerns.
Cyclopentasiloxane is not CG-method approved. Curly hair types may want to avoid this ingredient or use products containing it sparingly.
No, Cyclopentasiloxane is not approved for the Curly Girl method.
Some alternatives to Cyclopentasiloxane include: Isododecane, Caprylyl Methicone, lightweight plant oils
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