Cyclomethicone
Cyclomethicone (generic name for a mixture of cyclic siloxanes, typically D4, D5 and/or D6 in undisclosed ratios)
Cyclomethicone is not a single substance but a generic INCI name historically used for a blend of cyclic siloxanes, most often D4 (Cyclotetrasiloxane), D5 (Cyclopentasiloxane) and D6 (Cyclohexasiloxane) in varying, undisclosed proportions. Because the label does not reveal how much of each cyclic siloxane is present, the true EU-restricted-substance content, particularly D4, a Substance of Very High Concern and reproductive toxicant, cannot be verified from the ingredient list alone. Many brands have phased out this name in favour of declaring the specific cyclic siloxane to meet EU transparency expectations; treat a product listing 'Cyclomethicone' with the same caution as one listing D4 or D5 directly.
Function & Common Use
Solvent / Emollient / Carrier for silicones
Silicone
Older-generation silicone primers, foundations, hair serums and antiperspirants; increasingly replaced by brands naming the specific cyclic siloxane instead
Synthetic
Concentration Limits
No formal limit
Governed by the actual D4/D5/D6 content, which this blend name does not disclose
No specific 21 CFR cosmetic limit identified in source checked
No specific MFDS limit identified in source checked; verify if ingredient is used in a Korean functional cosmetic category
Format restriction: Cannot be assessed from the INCI name alone; depends on the undisclosed D4/D5/D6 ratio in the specific product
Baby restriction: Avoid; composition-dependent risk cannot be verified from the label
Pregnancy: Caution; may contain reprotoxic D4; exact composition is not disclosed on the label
Frequently Asked Questions
Is Cyclomethicone safe to use in skincare?
Cyclomethicone has a Medium concern rating. Cyclomethicone is not a single substance but a generic INCI name historically used for a blend of cyclic siloxanes, most often D4 (Cyclotetrasiloxane), D5 (Cyclopentasiloxane) and D6 (Cyclohexasiloxane) in varying, undisclosed proportions. Because the label does not reveal how much of each cyclic siloxane is present, the true EU-restricted-substance content, particularly D4, a Substance of Very High Concern and reproductive toxicant, cannot be verified from the ingredient list alone. Many brands have phased out this name in favour of declaring the specific cyclic siloxane to meet EU transparency expectations; treat a product listing 'Cyclomethicone' with the same caution as one listing D4 or D5 directly.
Is Cyclomethicone allowed in India?
Cyclomethicone is currently classified as "Permitted" under Indian cosmetics regulations. The maximum permitted concentration is No formal limit.
What is Cyclomethicone used for in cosmetics?
Cyclomethicone functions as: Solvent / Emollient / Carrier for silicones. It is commonly found in: Older-generation silicone primers, foundations, hair serums and antiperspirants; increasingly replaced by brands naming the specific cyclic siloxane instead.
Is Cyclomethicone safe for babies?
Cyclomethicone has baby/child restrictions: Avoid; composition-dependent risk cannot be verified from the label. Avoid using products containing this ingredient on infants unless specifically formulated and labelled for baby use.
Regulatory Status
Not independently regulated under this name; the underlying D4/D5/D6 content must still comply with EU Annex III and REACH Annex XVII limits
Cosmetic ingredient; standard TGA cosmetic framework applies; no therapeutic goods listing required unless therapeutic claims are made
Not specifically listed as restricted cosmetic ingredient in NHPID source checked; standard Health Canada cosmetic notification applies
EU Annex: Governed indirectly via EU Annex III / REACH Annex XVII Entry 70 (applies to the D4/D5/D6 actually present)
Identifiers
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