Silicones in hair and skin care: dimethicone, D4/D5/D6 and what “silicone-free” means
How to spot silicones in an ingredient list, why they are used, what the EU restriction on cyclic silicones D4, D5 and D6 covers, and how to read “silicone-free” claims.
Updated: 31 October 2026 · Reviewed by: Kamil Pyziak
What silicones are
Silicones are synthetic polymers built on a backbone of silicon and oxygen. In cosmetics they give slip, smoothness and shine, reduce stickiness and help other ingredients spread. They are common in hair conditioners, serums, primers, foundations and sunscreens.
Different silicones behave very differently: some are heavy and long-lasting, others light and volatile, and some are modified to be water-soluble or to bind to damaged hair.
How to recognise them on the label
Most silicone names end in “-methicone”, “-siloxane” or “-silane”, or contain “silicone”. Examples: Dimethicone, Dimethiconol, Amodimethicone, Phenyl Trimethicone, Cyclopentasiloxane, Cyclohexasiloxane and PEG-10 Dimethicone.
Names with PEG or PPG, such as PEG-10 Dimethicone, are silicones modified to mix with water more easily. Amodimethicone is a modified silicone that is attracted to damaged parts of the hair, which is why it is popular in conditioners.
Silicones in hair care
In hair products silicones smooth the cuticle, reduce friction when combing, cut frizz and add shine. Heat-protection sprays often rely on them to form a film on the hair surface.
A common concern is build-up. Water-soluble or volatile silicones rarely accumulate, while heavier ones can, especially on fine hair and with gentle cleansers. Whether this becomes a problem depends on your hair, your routine and the shampoo you use.
Silicones in skin care and make-up
In creams and make-up silicones give a silky, powdery finish, help foundations glide on and make sunscreens less greasy. Dimethicone also forms a light protective film and is listed in CosIng with skin-protecting functions.
Silicones are generally well tolerated. Whether a product feels heavy or clogs pores depends on the whole formula rather than on silicones alone.
The EU restriction on D4, D5 and D6
The cyclic silicones octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5) and dodecamethylcyclohexasiloxane (D6) are restricted in the EU because of environmental concerns: they are persistent and can accumulate in the environment. D4 and D5 had already been restricted in wash-off products; Commission Regulation (EU) 2024/1328 extended the restriction to leave-on cosmetics and other products, with transition periods.
On cosmetic labels D5 appears as Cyclopentasiloxane and D6 as Cyclohexasiloxane; Cyclomethicone is a mixture of cyclic silicones. Linear silicones such as Dimethicone are not covered by this restriction. For the exact scope and dates, see the EU regulation section of the ingredient pages.
What “silicone-free” means
“Silicone-free” usually means that no ingredient from the silicone family is in the formula. Such products replace silicones with plant oils, esters (for example Coco-Caprylate/Caprate), fatty alcohols or natural polymers. They are not automatically better or worse – they simply behave differently.
If you want to check a claim yourself, scan the INCI list for “-methicone”, “-siloxane” and “-silane”. Our analyser marks silicones with their functions, so you can do this quickly.
What the label does not tell you
The list shows which silicones are present, but not how much of each or how they will behave on your hair or skin. Two products with dimethicone can feel completely different. Judge by your own experience and treat “with silicones” or “silicone-free” as information about the formula style, not a verdict on quality.