Dimethicone 350 cSt

Non-Volatile Silicone for Smooth, Silky Skin & Hair Formulations

Dimethicone 350 cSt is a clear, non-volatile polydimethylsiloxane silicone fluid widely used in skincare, hair-care, makeup and personal-care formulations.

It is valued for its ability to improve:

• Slip
• Spreadability
• Smoothness
• Hair manageability
• Softness
• Shine
• Water repellency
• Sensory feel

Unlike volatile silicones such as Cyclopentasiloxane, Dimethicone 350 remains on the skin or hair after application and contributes to a smooth, lubricious film.

What Is Dimethicone 350?

Dimethicone is a silicone polymer based on polydimethylsiloxane.

The number 350 refers to its approximate viscosity:

350 centistokes (cSt)

This grade is more viscous than very low-viscosity Dimethicone fluids such as 5, 10 or 50 cSt.

INCI Name: Dimethicone
Chemical Family: Polydimethylsiloxane
Typical Viscosity: Approximately 350 cSt
Form: Clear, Colorless Silicone Fluid
Primary Functions: Conditioning / Emollient / Lubricity / Spreading / Sensory Modification

Main Cosmetic Functions

Dimethicone 350 can help provide:

• Smooth application
• Silky skin feel
• Hair conditioning
• Reduced tackiness
• Reduced greasy sensation
• Easier combing
• Increased shine
• Improved surface slip
• Water-repellent film

It is especially useful in formulations where a smooth and elegant sensory profile is desired.

Is Dimethicone 350 a Moisturizer?

Dimethicone is not a humectant like glycerin.

It does not actively attract water.

Instead, it forms a thin hydrophobic film on the skin surface that can help reduce excessive moisture loss and improve skin feel.

It is therefore more accurately described as:

• Emollient
• Skin-conditioning ingredient
• Protective film-forming ingredient

rather than a primary moisturizer.

Use in Skincare

Dimethicone 350 is widely used in:

• Face creams
• Body lotions
• Hand creams
• Facial serums
• Barrier creams
• Primers
• Body-care products

It can help improve:

• Spreadability
• Smoothness
• Slip
• Reduced tackiness
• Soft after-feel

Skin Barrier & Water Loss

Dimethicone can form a water-repellent film over the skin.

This may help reduce transepidermal moisture loss and support a smoother skin feel.

However, it should not be marketed as permanently repairing the skin barrier or treating irritated skin.

Hair Conditioning

Dimethicone 350 is particularly useful in hair-care formulations.

It can help improve:

• Wet combing
• Dry combing
• Detangling
• Smoothness
• Shine
• Softness
• Frizz control

It coats the hair surface and reduces friction between individual hair fibers.

Does Dimethicone Repair Hair?

Dimethicone does not biologically repair damaged hair.

Instead, it forms a temporary film over the hair fiber that can make damaged hair feel:

• Smoother
• Softer
• Easier to comb
• More uniform
• More glossy

This is a cosmetic conditioning effect rather than permanent structural repair.

Use in Hair Serums

Dimethicone 350 may be used in:

• Hair serums
• Anti-frizz products
• Shine products
• Leave-in treatments
• Split-end appearance products

Because it is non-volatile and more viscous than low-viscosity silicone fluids, it provides a more persistent conditioning film.

Use in Shampoo

Dimethicone can be used in shampoos, but simple Dimethicone 350 is not water-soluble.

This means it usually requires:

• Suitable emulsification
• Silicone dispersion technology
• Pre-emulsified silicone
• Appropriate surfactant system

to remain uniformly dispersed.

Directly adding neat Dimethicone 350 to a shampoo may lead to separation or poor distribution.

Use in Conditioners

It is more straightforward to incorporate into properly emulsified:

• Hair conditioners
• Hair masks
• Leave-in creams

where it can improve slip and conditioning.

Use in Makeup

Dimethicone 350 may be used in:

• Makeup primers
• Foundations
• BB creams
• Concealers
• Cream makeup
• Lip products

It helps create:

• Smooth application
• Improved slip
• More even spreading
• Reduced tackiness
• Soft-focus sensory feel

Use in Sunscreen Formulations

Dimethicone may be incorporated into sunscreen formulations to improve:

• Spreadability
• Water repellency
• Sensory properties
• Film uniformity

However:

Dimethicone is not a UV filter.

It does not provide SPF or UVA/UVB protection by itself.

All sun-protection claims must come from permitted UV filters and appropriate finished-product testing.

Use in Soap Making

Dimethicone 350 is not a conventional soap-making ingredient.

Traditional cold process soap relies on:

• Vegetable oils
• Fats
• Sodium hydroxide
• Saponification chemistry

Dimethicone does not participate in the saponification reaction.

Cold Process Soap

Routine addition of Dimethicone 350 to cold process soap is generally unnecessary.

Because silicone fluids can also have antifoaming properties, excessive use may reduce lather.

If tested experimentally:

• Use a low concentration.
• Evaluate compatibility.
• Monitor lather.
• Test bar hardness.
• Confirm final sensory performance.

Melt & Pour Soap

Small experimental amounts may be evaluated in some melt and pour bases.

However, excessive silicone may affect:

• Lather
• Clarity
• Bar hardness
• Surface feel
• Base compatibility

Always follow the soap-base manufacturer’s additive limits.

Typical Usage Levels

The correct level depends strongly on formulation type.

General formulation starting points may include:

Creams & Lotions

0.5–5%

Hair Conditioners

0.5–3%

Hair Serums

1–10%

Makeup Products

0.5–5%

Selected Cleansing Products

Usually low levels, depending on formulation and dispersion technology

These are practical starting ranges rather than universal limits.

Always follow the supplier TDS and test the finished product.

Oil & Water Compatibility

Dimethicone 350 is not water-soluble.

It is compatible with many:

• Silicone fluids
• Cosmetic esters
• Oils
• Waxes
• Anhydrous cosmetic systems

In water-containing formulations, it normally requires an appropriate emulsification or dispersion system.

Dimethicone 350 vs. Cyclopentasiloxane

These two silicones behave very differently.

Dimethicone 350

• Non-volatile
• Approximately 350 cSt viscosity
• Remains on skin and hair
• Provides lasting slip and conditioning
• Forms a persistent film

Cyclopentasiloxane

• Volatile
• Very lightweight
• Evaporates after application
• Mainly used as a volatile carrier
• Leaves a lighter dry-touch finish

They should not be treated as interchangeable ingredients.

Dimethicone 350 vs. Low-Viscosity Dimethicone

Dimethicone is available in many viscosity grades.

Examples include:

• 5 cSt
• 10 cSt
• 50 cSt
• 100 cSt
• 350 cSt
• 1,000 cSt
• 10,000 cSt+

Lower viscosity grades generally:

• Spread faster
• Feel lighter
• Flow more easily

Higher viscosity grades generally:

• Provide richer slip
• Produce a more substantial film
• Remain more strongly on hair and skin

Dimethicone 350 offers a balance between spreadability and persistent conditioning.

Is Dimethicone 350 Volatile?

No.

Dimethicone 350 is considered a non-volatile silicone fluid.

It does not rapidly evaporate from the skin or hair.

This distinguishes it from volatile silicones such as D5.

Antifoaming Properties

Dimethicone can reduce foam in some systems.

This property is useful industrially but may be undesirable in products where rich foam is expected.

Formulators should therefore be cautious when using it in:

• Shampoo
• Body wash
• Liquid soap
• Foaming cleanser
• Traditional soap

Excessive silicone can reduce foam performance.

pH Information

Dimethicone 350 is an anhydrous silicone oil.

Assigning it a fixed specification such as:

pH 5.0–7.0

is not particularly meaningful.

The pH of the complete water-containing finished product should instead be measured.

Product Details

Product Name: Dimethicone 350
INCI Name: Dimethicone
Chemical Type: Polydimethylsiloxane
Typical Viscosity: 350 cSt
Form: Clear, Colorless Liquid
Volatility: Non-Volatile
Water Solubility: Insoluble
Primary Functions: Hair Conditioning / Skin Conditioning / Emollient / Lubricity / Spreading
Applications: Hair Care, Skincare, Makeup and Personal-Care Formulations

Purity

Only describe the product as:

100% Dimethicone

if supported by the actual supplier COA.

Professional users should confirm:

• Viscosity
• Purity
• Cyclic siloxane content
• Specific gravity
• Refractive index
• SDS
• TDS
• COA

for the actual supplied batch.

Storage

Store Dimethicone 350:

• In tightly closed packaging
• In a cool and dry environment
• Away from contamination
• Away from excessive heat
• Away from direct sunlight where practical

Keep the package tightly closed after dispensing.

Safety Information

• For cosmetic formulation use.
• Avoid direct eye contact.
• Avoid ingestion.
• Avoid generating sprays or aerosols without appropriate safety evaluation.
• Use appropriate protective equipment during professional handling.
• Follow the supplier SDS and TDS.
• Evaluate the final cosmetic formulation for its intended use.

Wholesale, Private Label & Contract Manufacturing

We also supply Dimethicone 350, cosmetic silicones, emollients, esters and other formulation raw materials in wholesale quantities for cosmetic brands, laboratories, manufacturers, retailers and professional formulators.

In addition to raw material supply, we provide private label and contract manufacturing services for hair serums, conditioners, creams, lotions, primers, skincare products and other customized cosmetic formulations.

Custom products can be developed with different silicone systems, botanical oils, conditioning agents, active ingredients, fragrances, textures, viscosities, packaging formats and private label designs.

For bulk Dimethicone 350 orders, private label cosmetic products or contract manufacturing, please contact us with your required quantity, intended application, viscosity requirements, packaging format, target market and estimated production volume.