Cyclomethicone

SY-kloh-METH-ih-kone

Conditioning Agent, Solvent 7/10 Safety Not CGControversial Synthetic Vegan

What Is Cyclomethicone?

Cyclomethicone is a family of volatile (evaporating) cyclic silicone compounds, primarily cyclopentasiloxane (D5). Unlike dimethicone, it evaporates from the hair after application, leaving behind a smooth feel without long-term buildup. It acts as a lightweight carrier that helps distribute other ingredients evenly through the hair.

Source: Silica (sand), chemically synthesized

Origin: Synthetic

Also known as: Cyclopentasiloxane, D5, Cyclotetrasiloxane, D4, Volatile Silicone

What Does Cyclomethicone Do to Your Hair?

Cyclomethicone spreads easily through hair, carrying other conditioning agents and active ingredients along with it. As it evaporates, it leaves behind a smooth, silky feel and any non-volatile ingredients it was carrying. It provides instant detangling, heat protection, and frizz control without the heavy buildup associated with non-volatile silicones.

Best For

Fine hair, oily hair, heat-styled hair, all hair types wanting lightweight conditioning

Not Recommended For

Not significantly problematic for any hair type

Concentration Matters

1-50%

Hair Type Compatibility

1A Straight Fine
1B Straight Medium
1C Straight Coarse
2A Wavy Fine
2B Wavy Medium
2C Wavy Coarse
3A Curly Loose
3B Curly Tight
3C Curly Corkscrew
4A Coily S-Shaped
4B Coily Z-Shaped
4C Coily Tight

Method Compatibility

Curly Girl (CG) Method: Avoid
CG Avoid

Safety & Regulation

7/10
AvoidCautionSafe

Low toxicity for human use. Primary concern is environmental — D4 and D5 are persistent in the environment and bioaccumulative. The EU has restricted D4 and D5 in wash-off products at concentrations above 0.1%. Evaporates before significant skin/scalp absorption occurs.

FDA Status: Generally Recognized As Safe

FDA permits use in cosmetics without restrictions. EU has imposed environmental restrictions on D4 and D5 in rinse-off products since 2020.

EWG Score: 2/10

HairAide Verdict

Cyclomethicone is an excellent choice for those who want silicone-level smoothing without buildup concerns. Because it evaporates, it will not accumulate on hair between washes. HairAide notes it is not CG-approved due to being a silicone, but it is one of the least problematic silicones from a hair health standpoint. Environmental concerns are worth noting.

Products That Contain Cyclomethicone

Heat protectants, serums, lightweight conditioners, detangling sprays, styling sprays

Alternatives to Cyclomethicone

If you want to avoid Cyclomethicone, look for products with these ingredients instead:

Isododecane, Caprylyl Methicone, C13-15 Alkane

Frequently Asked Questions

Is Cyclomethicone safe for hair?

Yes, Cyclomethicone has a safety rating of 7/10 and is generally considered safe for use in hair products. Low toxicity for human use. Primary concern is environmental — D4 and D5 are persistent in the environment and bioaccumulative. The EU has restricted D4 and D5 in wash-off products at concentrations above 0.1%. Evaporates before significant skin/scalp absorption occurs.

Is Cyclomethicone bad for curly hair?

Cyclomethicone is not CG-method approved. Curly hair types may want to avoid this ingredient or use products containing it sparingly.

Is Cyclomethicone CG-method approved?

No, Cyclomethicone is not approved for the Curly Girl method.

What can I use instead of Cyclomethicone?

Some alternatives to Cyclomethicone include: Isododecane, Caprylyl Methicone, C13-15 Alkane

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