Cycloheptasiloxane

What is Cycloheptasiloxane?

Cycloheptasiloxane is a synthetic organosilicon compound featuring a seven-membered ring of alternating silicon and oxygen atoms, each silicon bound to two methyl groups. Produced through hydrolysis and polymerization of dimethyldichlorosilane, it belongs to the family of cyclic polydimethylsiloxanes used widely in color cosmetics, hair care, and skincare formulations. In products, it acts primarily as a volatile solvent and carrier, rapidly spreading ingredients across the skin or hair due to its low surface tension and viscosity. Upon application, it evaporates cleanly without residue, delivering a non-greasy, smooth finish while aiding in the even distribution of pigments and actives. Its emollient properties temporarily soften skin texture, and it supports powder flow in dry formulations by preventing clumping.

Comedogenic Rating 0/5 Low risk of clogging pores

EWG Safety Rating 1 View on EWG →

Roles in Formulation

This ingredient serves the following purposes in cosmetic formulations:

Anticaking agent

Prevents powders from clumping by reducing moisture pickup and improving flow, keeping loose and pressed powders uniform during storage and use.

Emollient

Softens and smooths skin by filling in surface roughness and improving slip; can also help reduce moisture loss when paired with occlusives and film formers.

Solvent

Dissolves and carries other ingredients, helping control viscosity, evaporation rate, and delivery of actives in both water- and oil-based systems.

Skin conditioning agent

Maintains skin softness, smoothness, and flexibility.

Benefits

Improves product glide and even application for a smooth, silky texture.

Evaporates quickly to leave a lightweight, non-oily finish.

Helps maintain powder uniformity and reduces moisture absorption in dry products.

Who It's For

A quick guide for who this ingredient may suit (and who should be cautious).

Who May Benefit	Who Should Avoid
People seeking lightweight formulas in makeup primers and foundations.	Those with rare silicone sensitivities.
Individuals preferring quick-drying hair sprays and styling aids.	People preferring silicone-free products for personal reasons.
Users wanting enhanced spreadability in emollient-free skincare.	Individuals concerned about environmental persistence of siloxanes.

Safety Notes

Rated low hazard by EWG with scores of 1 across concerns.
Generally recognized as safe for cosmetic use with low irritation potential.

Frequently Asked Questions about Cycloheptasiloxane

What is cycloheptasiloxane used for in cosmetics?

It serves as a solvent, emollient, and skin conditioner to improve spreadability and provide a silky feel in makeup and hair products.

Is cycloheptasiloxane safe for skin?

It has a low EWG rating of 1 and is considered safe with minimal irritation risk in cosmetic concentrations.

Does it cause acne?

No, it has a comedogenic rating of 0, making it suitable for acne-prone skin.