Ingredient
Cyclohexasiloxane
Cyclohexasiloxane is flagged for pregnancy, trying to conceive and PCOS. The concern behind the strongest flag is endocrine disruptor and absorbed into the body.
- D6
- Hexamethylcyclotrisiloxane
Verdict by profile
Truva checks every ingredient against six profiles. Jump to any of them for the full assessment.
- Strongest verdict
- Caution Advised
- Its verdict for pregnancy, the profile this one is worst in
- Profiles flagged
- 3 of 6
- Counting avoid, high risk and medium risk
- Irritancy
- 0 of 5
- Higher means more likely to sting or redden
Cyclohexasiloxane and pregnancy
Caution Advised
- Endocrine disruptor
- Absorbed into the body
Cyclohexasiloxane (D6) is a volatile cyclic silicone that provides slip and helps other ingredients spread on skin. It's commonly found in primers, foundations, and hair products because it evaporates quickly without leaving residue. According to ECHA, D6 has been flagged for potential reproductive toxicity based on animal studies showing effects on fertility and development. While topical absorption is limited due to its volatility, the ingredient's classification as a potential reproductive toxicant raises concerns during pregnancy. Studies in rats showed decreased fertility and developmental effects at high doses, though human data on topical use is limited. The European Chemicals Agency lists D6 as a substance of very high concern due to these reproductive effects. While there's no explicit guidance from ACOG on topical cyclohexasiloxane, many dermatologists recommend that pregnant women choose products without ingredients flagged for reproductive toxicity when safer alternatives exist. The concern is primarily theoretical for topical use, as systemic exposure from cosmetics is minimal compared to oral or inhalation exposure.
Cyclohexasiloxane and breastfeeding
Safe to Use
Cyclohexasiloxane is a volatile silicone that evaporates from the skin surface rather than penetrating deeply. Its high volatility means it primarily stays on the skin surface before evaporating into the air. While D6 is classified as very bioaccumulative in the environment, the rapid evaporation from cosmetic products significantly limits systemic absorption. The likelihood of meaningful transfer to breast milk is very low due to minimal dermal penetration. No specific concerns have been raised by medical organizations regarding breastfeeding mothers using topical products containing cyclohexasiloxane. Most dermatologists consider topical use acceptable during breastfeeding given the low absorption and rapid evaporation. The primary concerns with D6 relate to environmental persistence rather than direct health effects from cosmetic use. Standard application to facial skin poses minimal risk to breastfed infants.
Cyclohexasiloxane and postpartum
Safe to Use
Cyclohexasiloxane provides cosmetic benefits by creating smooth application and a silky skin feel. For postpartum women not breastfeeding, the reproductive toxicity concerns that apply during pregnancy are no longer relevant. The ingredient's environmental classification as vPvB (very persistent, very bioaccumulative) is notable, but for personal health during the postpartum period, topical use presents minimal direct risk. The rapid evaporation and low skin penetration limit systemic exposure. Women may choose to avoid it for environmental reasons, but health concerns specific to the postpartum period are minimal.
Cyclohexasiloxane and trying to conceive
Caution Advised
- Fertility effects
Women trying to conceive should follow pregnancy-safe guidelines, and cyclohexasiloxane's reproductive toxicity classification makes it a consideration. ECHA's classification was based on animal studies showing decreased fertility at high exposure levels. While topical cosmetic use provides much lower exposure than the doses that caused effects in animal studies, many fertility specialists recommend minimizing exposure to ingredients classified for reproductive toxicity when trying to conceive. The precautionary principle suggests choosing products without reproductive toxicity flags during the preconception period. Switching to alternative silicones or emollients is a reasonable approach.
Cyclohexasiloxane and PCOS
Caution Advised
- Endocrine disruptor
For women with PCOS, who already experience hormonal imbalances, ingredients with potential endocrine-disrupting properties warrant consideration. Cyclohexasiloxane's classification by ECHA as having reproductive toxicity includes concerns about hormonal effects. While the evidence for endocrine disruption from topical silicones is limited and primarily based on high-dose animal studies, women managing PCOS may prefer to minimize exposure to any ingredients with potential hormonal activity. The actual impact of cosmetic use on PCOS symptoms or hormone levels has not been studied. There is no medical consensus that topical cyclohexasiloxane worsens PCOS or interferes with treatment. However, given the availability of alternative silicones without reproductive toxicity classifications, some women with PCOS choose to avoid D6 as a precautionary measure.
Cyclohexasiloxane and general use
Safe to Use
- Environmental pollutant
For the general population without pregnancy or fertility concerns, cyclohexasiloxane is considered safe for topical use in cosmetics. It has been used in personal care products for decades with minimal reports of adverse skin reactions. The ingredient is non-irritating and well-tolerated by most skin types. The primary concern with D6 is environmental rather than personal health-related. According to ECHA, the substance is very persistent and very bioaccumulative in aquatic environments. The EU has restricted its use in rinse-off products to reduce environmental contamination. Individual health risks from cosmetic use are minimal given low skin absorption and rapid evaporation. The FDA and Health Canada continue to allow cyclohexasiloxane in cosmetics, finding it safe for consumers. Environmental considerations have led some consumers and brands to phase out cyclic silicones in favor of linear silicones or plant-based alternatives, but this is primarily an environmental rather than personal safety decision.
Everything else flagged for the same profiles
Related ingredients
Ingredients suggested in place of Cyclohexasiloxane, each one with its own page here.
Cyclohexasiloxane is itself suggested as the safer option on these pages.
Ingredients that raise the same concerns.
Where this came from
Truva summarises published guidance from bodies including ACOG, the FDA, the EU SCCS and the Cosmetic Ingredient Review. It has no access to your medical history and it is not a substitute for your doctor, dermatologist or midwife. These assessments have not been reviewed by a clinician, and nothing here is a diagnosis or a prescription. If you are pregnant, breastfeeding or being treated for PCOS, take the ingredient list to the person looking after you.
Assessment last pulled from the ingredient database on .
One ingredient is the easy case.
A label has thirty of them. Truva reads the whole list at once and answers for the profile you set: pregnancy, breastfeeding, postpartum, trying to conceive, PCOS, or general use.
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