Ingredient review
Myristyl Trisiloxane
INCI: MYRISTYL TRISILOXANE
A lightweight silicone that smooths skin and hair without heaviness, generally well-tolerated but not biodegradable.
In plain English
Myristyl trisiloxane is a type of silicone oil used in cosmetics. It feels very light and silky on the skin, unlike heavier oils that can feel greasy. It helps products spread smoothly and leaves a soft, velvety finish. Because it sits on the surface, it can also help lock in moisture and reduce frizz in hair. It is considered safe for most people but is not easily broken down in the environment.
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
Myristyl Trisiloxane 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 Myristyl Trisiloxane.
- 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
Myristyl trisiloxane is a synthetic silicone polymer made from a trisiloxane backbone (three silicon atoms) with a myristyl (14-carbon) alkyl chain attached. It belongs to the class of volatile or low-viscosity silicones, similar to dimethicone but lighter.
How it works
It forms a thin, flexible film on the skin or hair surface. This film reduces friction, making the skin feel smooth and hair feel silky. It also helps other ingredients spread evenly and can temporarily fill in fine lines or rough patches by creating an even surface. Because it is non-occlusive (does not completely block pores), it allows some water vapor to escape, reducing the risk of clogged pores compared to heavier silicones.
Pros
Lightweight feel
Unlike heavier oils or silicones, myristyl trisiloxane spreads thinly and leaves a velvety finish that doesn't weigh down skin or hair.
Good spreadability
It helps creams and serums glide on evenly, so you need less product to cover your face, making it cost-effective.
Cons and cautions
Environmental persistence
As a silicone, it does not readily biodegrade, which raises concerns about accumulation in waterways and ecosystems.
Potential buildup
On hair, frequent use without clarifying shampoos can lead to a dull, heavy coating over time.
Best for
- People with normal to oily skin who want a lightweight moisturizer
- Those looking for a primer that smooths skin without heaviness
Use caution if
- Individuals who prefer completely silicone-free or biodegradable formulations
Usage tips
Safety summary
Myristyl trisiloxane has a low irritation and sensitization potential based on available safety data. It is considered safe for use in cosmetics at typical concentrations. However, long-term environmental concerns exist.
Research notes
Safety assessments by the Cosmetic Ingredient Review (CIR) panel have concluded that trisiloxane compounds are safe when used as intended. Most evidence comes from industry-sponsored studies and expert panel reviews rather than independent clinical trials.
Common label clues
- Typical concentration
- 1% to 10%
- Regulatory status
- Approved for use in cosmetics in the US (FDA), EU (CosIng), and many other regions. No concentration restrictions are typically imposed.
- Common uses
- Moisturizers, Serums, Primers, Hair conditioners, Styling products
- Environmental note
- Silicones like myristyl trisiloxane are not biodegradable and can persist in the environment. Some brands are moving toward biodegradable alternatives.
Good to know
- Myristyl trisiloxane is often used in 'silicone blends' to adjust the feel of a product.
- It is considered non-comedogenic by most dermatological sources, but individual reactions vary.
Common questions
What is Myristyl Trisiloxane in beauty products?
Myristyl trisiloxane is a type of silicone oil used in cosmetics. It feels very light and silky on the skin, unlike heavier oils that can feel greasy. It helps products spread smoothly and leaves a soft, velvety finish. Because it sits on the surface, it can also help lock in moisture and reduce frizz in hair. It is considered safe for most people but is not easily broken down in the environment.
What does Myristyl Trisiloxane do in a beauty product?
It forms a thin, flexible film on the skin or hair surface. This film reduces friction, making the skin feel smooth and hair feel silky. It also helps other ingredients spread evenly and can temporarily fill in fine lines or rough patches by creating an even surface. Because it is non-occlusive (does not completely block pores), it allows some water vapor to escape, reducing the risk of clogged pores compared to heavier silicones.
Is Myristyl Trisiloxane safe for most people?
Myristyl trisiloxane has a low irritation and sensitization potential based on available safety data. It is considered safe for use in cosmetics at typical concentrations. However, long-term environmental concerns exist.
Who should be careful with Myristyl Trisiloxane?
Individuals who prefer completely silicone-free or biodegradable formulations
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.