Ingredient review
Cyclotrisiloxane
INCI: Cyclotrisiloxane
A fast-evaporating silicone that gives a smooth, silky finish but has raised some environmental and safety questions.
In plain English
Cyclotrisiloxane is a lightweight, liquid silicone that evaporates quickly when applied to skin or hair. It helps products spread easily, leaves a non-greasy, silky feel, and can help other ingredients absorb better. Because it evaporates, it doesn't build up on the skin like heavier silicones can.
Review score
Safety, usefulness, and evidence
Potentially useful with some tradeoffs
The evidence base is useful, but some claims depend heavily on the formula.
Risk flags are low for most users, though the finished product can still irritate.
- Source
- synthetic
- Evidence
- moderate
- Irritation
- low
- Clogging risk
- low
Quick decision guide
Useful, but context matters
Cyclotrisiloxane is generally a lower-concern ingredient when the full formula suits your skin.
Plain-English read
Treat this as a practical screening step before you compare products that contain this ingredient.
- Step 1Start with the score, then check the irritation and clogging risk before judging Cyclotrisiloxane.
- Step 2Use the "Best for" and "Use caution if" sections to match the ingredient to your skin, not just to a marketing claim.
- Step 3If a product stings, breaks you out, or worsens irritation, judge the finished formula and stop using it even if the ingredient scores well.
Score terms in plain English
Irritation risk
lowLess likely to sting, burn, or bother most users, though sensitive skin can still react.
Clogging risk
lowLess likely to feel heavy or contribute to clogged pores for most skin types.
Evidence level
moderateThere is useful support, but formula details and claim strength still matter.
What it is
A cyclic silicone (a ring-shaped molecule made of silicon and oxygen) that is volatile, meaning it turns into a gas at skin temperature. It is synthetically produced and commonly used in cosmetics as a carrier or spreading agent.
How it works
When applied, cyclotrisiloxane spreads into a thin, even film and then quickly evaporates, leaving behind a smooth, dry feel. This temporary film can help other active ingredients spread more evenly and may reduce the sticky or greasy feel of heavier oils or emollients.
Pros
Silky, lightweight feel
Creates a smooth, non-greasy finish that many people love, especially under makeup or in humid weather.
Improves product texture
Helps creams and serums spread easily and evenly, reducing the need to rub or tug at the skin.
Cons and cautions
Environmental concerns
Cyclotrisiloxane is considered persistent and may bioaccumulate in aquatic environments, leading to regulatory restrictions in some regions.
Potential for dryness
Because it evaporates quickly, it can leave the skin feeling dry if used alone or in high concentrations, especially for dry skin types.
Best for
- People who prefer a lightweight, non-greasy finish
- Those with oily or combination skin looking for a smooth base under makeup
Use caution if
- Individuals concerned about environmental impact of silicones
- Those with very dry or dehydrated skin who may prefer more occlusive ingredients
Usage tips
Safety summary
Generally considered safe for topical use in cosmetics at typical concentrations. Skin irritation and allergy are rare. The main concerns are environmental rather than human health, though some regulatory bodies have flagged potential long-term risks.
Research notes
Human health studies show low acute toxicity and low skin irritation potential. Environmental studies highlight persistence and bioaccumulation in aquatic organisms. Regulatory agencies like ECHA have imposed restrictions to limit environmental release.
Common label clues
- Typical concentration
- 1–15% in leave-on products
- Regulatory status
- Approved for use in cosmetics in the US and many other countries. In the EU, cyclotrisiloxane is restricted in rinse-off products above 0.1% due to environmental persistence concerns. Always check local regulations.
- Common uses
- Primers, Serums, Moisturizers, Sunscreens, Hair products
- Environmental note
- Cyclotrisiloxane is classified as very persistent and very bioaccumulative (vPvB) under REACH, leading to restrictions in some regions. It can accumulate in water and wildlife.
Good to know
- Cyclotrisiloxane is the smallest of the cyclic silicones (D3, D4, D5, D6) and evaporates fastest.
- It is often used in 'water-free' or anhydrous formulas to deliver actives without water.
- Some brands have voluntarily phased out cyclic silicones due to environmental concerns.
Common questions
What is Cyclotrisiloxane in beauty products?
Cyclotrisiloxane is a lightweight, liquid silicone that evaporates quickly when applied to skin or hair. It helps products spread easily, leaves a non-greasy, silky feel, and can help other ingredients absorb better. Because it evaporates, it doesn't build up on the skin like heavier silicones can.
What does Cyclotrisiloxane do in a beauty product?
When applied, cyclotrisiloxane spreads into a thin, even film and then quickly evaporates, leaving behind a smooth, dry feel. This temporary film can help other active ingredients spread more evenly and may reduce the sticky or greasy feel of heavier oils or emollients.
Is Cyclotrisiloxane safe for most people?
Generally considered safe for topical use in cosmetics at typical concentrations. Skin irritation and allergy are rare. The main concerns are environmental rather than human health, though some regulatory bodies have flagged potential long-term risks.
Who should be careful with Cyclotrisiloxane?
Individuals concerned about environmental impact of silicones Those with very dry or dehydrated skin who may prefer more occlusive ingredients
Research sources
Ingredient reviews are educational and are not medical advice. Patch test new products and ask a licensed clinician about persistent irritation, allergies, pregnancy-specific questions, or diagnosed skin conditions.