Co-Wash: What It Is, Who It’s Best For & How to Formulate It

For curly, coily, textured, dry, and fragile hair, a co-wash provides a gentle way to cleanse while helping the hair retain softness, moisture, slip, and manageability.

But from a cosmetic formulator’s perspective, a co-wash is more than simply “washing the hair with conditioner.”

A well-formulated co-wash is a cleansing conditioner, a product designed to provide enough cleansing to remove light oils, sweat, dirt, and everyday buildup while simultaneously conditioning the hair.

The result is a product that sits somewhere between a traditional shampoo and a traditional rinse-off conditioner.

What Is a Co-Wash?

The term co-wash is short for conditioner wash.

Instead of cleansing with a conventional shampoo containing a stronger surfactant system, a co-wash uses a much milder cleansing system combined with conditioning ingredients.

A traditional shampoo is primarily designed to:

• Cleanse the scalp and hair
• Remove oil
• Remove dirt
• Remove styling-product buildup
• Produce noticeable lather

A conditioner is primarily designed to:

• Detangle
• Reduce static
• Smooth the hair
• Improve softness
• Add slip
• Improve manageability

A co-wash brings these two functions together.

A Co-Wash Should:

Cleanse + Condition + Detangle + Soften

The cleansing portion should be mild enough that the hair does not feel stripped after rinsing, while the conditioning system should leave the hair soft and manageable.

Commercial formulation examples show this combination clearly. A low-foaming co-wash formula can pair the mild amphoteric surfactant Cocamidopropyl Betaine with a cationic conditioning ingredient, fatty alcohol, emollient oils, cationic guar, humectants, and other conditioning ingredients.

Who Is Co-Washing Best For?

Co-washing can technically be formulated for many hair types, but it is particularly useful for hair that tends to become dry when shampooed frequently.

It is especially well suited to:

Curly Hair

Curly hair tends to be more susceptible to dryness because natural scalp oils do not travel as easily down a curved hair strand.

Curly and tightly coiled hair is more prone to dryness and breakage and often benefits from more conditioning and less frequent washing.

Coily and Type 4 Hair

Co-washes can be particularly useful for:

• Type 3C
• Type 4A hair
• Type 4B hair
• Type 4C hair
• Highly textured hair
• Very dry hair
• Hair prone to tangling
• Hair prone to breakage

For these hair types, the conditioning and detangling portion of the formulation can be just as important as cleansing.

Dry Hair

People with dry hair may find that frequent shampooing leaves the hair feeling rough or stripped.

A co-wash provides a way to refresh the scalp and hair while depositing conditioning ingredients at the same time.

Thick or Coarse Hair

Thicker and coarser hair generally tolerates richer conditioning systems well and may particularly benefit from the creamy texture and additional slip of a co-wash.

Color-Treated or Chemically Processed Hair

Mild cleansing systems can also be useful when formulating for hair that is:

• Color treated
• Bleached
• Relaxed
• Chemically processed
• Heat damaged
• High porosity

The goal is not to eliminate cleansing, but to make cleansing less stripping.

Is Co-Wash Good for Fine or Oily Hair?

It can be, but the formulation needs to be different.

Fine hair generally needs a lighter conditioning system than coarse or tightly coiled hair.

Too much:

• Fatty alcohol
• Oil
• Butter
• Cationic conditioning agent
• Conditioning polymer

can leave fine hair feeling weighed down.

Fine or straight hair usually requires lighter conditioning than dry or curly hair.

Someone with a very oily scalp or significant product buildup may also need a traditional or clarifying shampoo periodically.

Co-washing does not necessarily need to replace shampoo completely.

Think of it as another cleansing option within the hair-care routine.

How Do You Use a Co-Wash?

A co-wash is used somewhat differently from a regular conditioner because the scalp needs to be cleansed.

Step 1: Thoroughly Detangle and Wet the Hair

Detangle all strands of hair and completely saturate the scalp and hair with warm water.

Water helps loosen dirt, oil, sweat, and water-soluble buildup before the product is even applied.

Step 2: Apply Co-Wash to the Scalp and Hair

Apply the co-wash to the scalp, roots and hair.

Use enough product to distribute throughout the scalp.

Step 3: Massage the Scalp

Massage gently with the fingertips.

This mechanical action is very important with a low-lather cleansing product.

Massage for approximately one to two minutes, paying particular attention to areas where oil and product accumulate.

Step 4: Distribute Through the Hair

Work the product through the lengths of the hair.

For curly, coily, or easily tangled hair, this is also an excellent time to gently detange.

Step 5: Rinse Thoroughly

Rinse thoroughly with water.

Depending on the formulation and hair type, a separate conditioner may not be necessary.

Does a Co-Wash Lather?

Usually very little.

This is one of the most important characteristics of a co-wash.

A co-wash is generally:

Low Lather → Low Foam → Mild Cleansing

It should not normally produce the large amount of foam associated with traditional shampoo.

However:

Low lather does not mean no cleansing.

Foam and cleansing are related to surfactant selection, but a product does not need abundant foam to clean the hair.

For example, Cocamidopropyl Betaine is a mild amphoteric surfactant that can provide cleansing and foam and is compatible with nonionic, anionic, and cationic surfactants.

How Much Lather Should You Formulate For?

For a traditional creamy co-wash, I prefer:

Low to very low lather.

You may see a light creamy foam when massaging the scalp, but the goal is not to create shampoo-like bubbles.

Too much surfactant can begin moving the formulation away from a cleansing conditioner and closer to a conditioning shampoo.

How Is a Co-Wash Formulated?

When I formulate a co-wash, I think of it as a conditioner structure with a gentle cleansing system incorporated into it.

This is very different from simply taking a shampoo formulation and adding extra conditioner.

The formulation needs to balance:

Cleansing

Enough to remove light soil, sweat, excess oil, and everyday buildup.

Conditioning

Enough to leave the hair soft, smooth, and manageable.

Slip

Especially important for curly and coily hair because the product may be used while detangling.

Rinse

The product should rinse cleanly without leaving the scalp heavily coated.

Deposition

Conditioning ingredients should remain on the hair after rinsing without causing excessive accumulation.

That balance is what makes co-wash formulation interesting.

Main Categories of Ingredients in a Co-Wash

A professional co-wash formulation will generally contain ingredients from several important categories.

1. Water Phase

Most co-washes are water-based products.

The water phase may include:

• Distilled water
• Hydrosols
• Aloe
• Botanical waters

Water makes up the continuous phase of the formulation and carries many of the water-soluble ingredients.

2. Mild Cleansing Surfactants

This is what separates a true cleansing co-wash from simply applying conditioner to the scalp.

The surfactant system should generally be much milder than the system used in a conventional shampoo.

Useful categories include:

Amphoteric Surfactants

Examples include:

• Cocamidopropyl Betaine
• Coco Betaine
• Cocamidopropyl Hydroxysultaine
• Sodium Cocoamphoacetate
• Sodium Lauroamphoacetate

These are particularly useful because they can contribute cleansing while maintaining mildness.

Nonionic Surfactants

Depending on the complete system, formulators may also work with mild nonionic surfactants such as glucosides.

The surfactant package should be evaluated as an entire system rather than selecting ingredients solely because an individual surfactant is described as “mild.”

3. Cationic Conditioning Ingredients

Conditioning is one of the defining characteristics of a co-wash.

Cationic ingredients are attracted to damaged and negatively charged areas of the hair and help improve:

• Detangling
• Slip
• Smoothness
• Static control
• Manageability
• Wet combing
• Dry combing

Depending upon your formulation system, examples may include:

• Behentrimonium Methosulfate
• Behentrimonium Chloride
• Cationic Emulsifying Systems

A low-foaming co-wash, for example, can combine a betaine surfactant with Behentrimonium Chloride as its conditioning ingredient.

4. Fatty Alcohols

Fatty alcohols are extremely important in this type of formulation.

Examples include:

• Cetyl Alcohol
• Cetearyl Alcohol
• Behenyl Alcohol

Fatty alcohols can contribute:

• Viscosity
• Creaminess
• Body
• Slip
• Softness
• Improved sensory feel

These are very different from drying alcohols such as ethanol.

In fact, dermatologists specifically identify fatty alcohols such as cetyl and stearyl alcohol as useful ingredients in conditioning products for curly and dry hair.

5. Conditioning Polymers

Conditioning polymers can dramatically improve the performance of a co-wash.

Examples include:

• Guar Hydroxypropyltrimonium Chloride
• Polyquaternium-7
• Polyquaternium-10

These can improve:

• Wet combing
• Slip
• Detangling
• Hair feel
• Frizz control
• Conditioning deposition

A cationic guar, for example, is included in one published low-foaming co-wash formulation.

Do not assume that more is better. Too much conditioning polymer can cause buildup or leave the hair feeling coated.

6. Humectants

Humectants can support hydration and improve the feel of the formulation.

Options may include:

• Glycerin
• Panthenol
• Sodium PCA
• Betaine
• Saccharide Isomerate

The type and amount should be adjusted to the hair type, climate, and desired finished feel.

7. Emollients

A small oil phase can add richness and improve softness.

Examples might include:

• Jojoba Oil
• Argan Oil
• Marula Oil
• Meadowfoam Seed Oil
• Hemisqualane
• Lightweight esters

For coarse, very dry, or coily hair, slightly richer emolliency may be desirable.

For fine hair, keep the oil phase lighter.

Again, the objective is:

Conditioning without excessive buildup.

8. Hair-Care Actives

This is where a formulator can customize the product.

Depending on the desired benefits, you might consider:

• Panthenol
• Hydrolyzed plant proteins
• Plant keratin alternatives
• Amino acids
• Beta-glucan
• Botanical extracts
• Hair and scalp soothing ingredients

These should enhance the primary formula rather than compensate for an unbalanced cleansing and conditioning system.

9. Preservative

Because a co-wash contains water, it requires an appropriate broad-spectrum preservation system.

Preservative selection needs to take into consideration:

• Finished-product pH
• Ingredient compatibility
• Manufacturing process
• Packaging
• Intended market
• Supplier recommendations

Preservation should always be verified through appropriate microbial and stability testing.

10. Chelating Agent

A chelating agent can be very helpful in a hair-cleansing product.

Examples include:

• Sodium Phytate
• Tetrasodium Glutamate Diacetate
• Other suitable cosmetic chelators

Chelators bind metal ions and can help support product stability and preservation.

11. pH Adjuster

The final pH should always be measured after the formulation is complete.

Citric acid or lactic acid solutions are commonly used when the pH needs to be lowered.

What Should the pH of a Co-Wash Be?

A useful target for many co-wash formulations is approximately:

pH 4.5–5.5

I especially like the range around:

pH 4.5–5.0

for many conditioning hair products, provided that range is appropriate for all of the ingredients and the preservation system being used.

Interestingly, a published low-foaming co-wash formulation specifies a finished pH of 4.5–5.0.

An acidic finished pH is useful in conditioning hair-care formulations and generally contributes to a smoother hair feel.

Always remember:

The final pH belongs to the finished formulation—not simply the water phase.

Measure after the product has been fully manufactured and cooled.

What Should the Viscosity of a Co-Wash Be?

There is no single required viscosity for a co-wash. I’ve formulated low-medium and medium viscosity co-washes.

However, I generally think of a traditional co-wash as having a:

Medium to Medium-High Viscosity

The finished product often resembles:

• A creamy conditioner
• A cleansing cream
• A medium-viscosity lotion
• A pumpable conditioner
• A squeezable conditioner

rather than a thin shampoo.

The exact viscosity depends on:

• Surfactant system
• Conditioning emulsifier
• Fatty alcohol level
• Cationic polymer
• Gum or rheology modifier
• Oil phase
• Electrolytes
• pH

Packaging Matters Too

A pump bottle generally requires a more pumpable viscosity.

A squeeze tube or jar can accommodate a thicker formulation.

So viscosity should never be developed independently of the packaging and consumer experience.

Instead of automatically adding more thickener, build viscosity through the entire formulation structure.

The Importance of Slip in a Co-Wash

For me, this is one of the most important performance characteristics of a co-wash.

Especially for curly, coily, thick, and textured hair:

A good co-wash should have excellent slip.

Slip is the lubricated, silky feeling that allows the fingers or comb to move through wet hair with less resistance.

Good slip can make detangling easier and reduce pulling and manipulation of fragile wet hair.

Slip can come from the combination of:

• Cationic conditioning ingredients
• Fatty alcohols
• Conditioning polymers
• Emollients
• The emulsifying system

It is the complete formulation—not one magic ingredient—that creates great slip.

How Much Cleansing Should a Co-Wash Provide?

This is one of the most important questions when developing the formulation.

Too little cleansing and the user may experience:

• Oily roots
• Heavy buildup
• Flat hair
• Scalp residue

Too much cleansing and you lose the purpose of the co-wash.

You may experience:

• Dryness
• Roughness
• Tangling
• Increased frizz
• A stripped hair feel

For formulation development, I generally begin with a low active surfactant level compared with a conventional shampoo and then evaluate cleansing through actual hair testing.

A useful development range may be approximately 3–8% total active surfactant matter, depending upon the surfactants selected and the intended hair type.

This is a formulation starting point, not a rule.

Always calculate the active surfactant matter, because a raw material supplied at 30% active is very different from one supplied at 50% or 100% active.

Co-Wash vs. Shampoo

Neither product is inherently better.

They simply perform different jobs.

Does Someone Who Co-Washes Ever Need Shampoo?

Usually, yes.

Even someone who regularly co-washes may periodically benefit from a traditional shampoo and clarifying shampoo to remove buildup, particularly if they use:

• Heavy oils
• Butters
• Waxes
• Styling creams
• Gels
• Edge-control products
• Dry shampoo
• Products prone to buildup

Formulating Co-Wash for Different Hair Types

One co-wash does not need to work for every hair type.

This is where professional formulation becomes exciting.

Fine or Wavy Hair

Consider:

• Lower conditioning-emulsifier level
• Lightweight emollients
• Lower fatty alcohol
• Minimal oil
• Good rinse
• Slightly stronger cleansing

Curly Hair

Focus on:

• Mild cleansing
• Excellent slip
• Detangling
• Moisture
• Moderate conditioning

Coily / Type 4 Hair

Consider:

• Richer conditioning system
• Excellent wet slip
• Strong detangling performance
• Good substantivity
• Emollients
• Conditioning polymers
• Low stripping potential

Hair With Heavy Product Buildup

Increase cleansing carefully or position the co-wash for use between periodic shampoo or clarifying treatments.

A Simple Co-Wash Formulation Structure

Instead of thinking first about specific percentages, begin by designing the functional architecture of the formulation.

A professional co-wash might contain:

Water Phase
Distilled water + humectants + chelator

↓

Mild Cleansing System
Amphoteric and/or mild nonionic surfactants

↓

Conditioning System
Cationic conditioner or conditioning emulsifier

↓

Structure + Slip
Fatty alcohols + conditioning polymer

↓

Emollients
Lightweight oils and/or esters

↓

Hair-Care Actives
Panthenol + proteins/amino acids + botanical ingredients

↓

Protection
Broad-spectrum preservative

↓

Final Adjustment
pH approximately 4.5–5.5, as appropriate for the complete formula

The exact percentages depend upon the specific ingredients, their active concentrations, supplier requirements, target hair type, packaging, and desired performance.

Free Download Co-Wash: What It Is, Who It’s Best For, & How To Formulate It

The Goal of a Well-Formulated Co-Wash

A good co-wash should not simply feel like conditioner being rubbed onto the scalp.

It should provide a noticeable, but gentle, cleansing effect.

After rinsing, the hair should feel:

• Clean
• Soft
• Smooth
• Conditioned
• Detangled
• Manageable
• Moisturized

without feeling:

• Stripped
• Squeaky
• Dry
• Greasy
• Excessively coated
• Heavy

That balance between cleansing and conditioning is the key to formulating an exceptional co-wash.

And just like shampoo and conditioner, a co-wash can be customized for very different hair types and concerns.

That is the beauty of cosmetic formulation: rather than trying to make one product work for everyone, we can understand the function of each ingredient and create a formulation specifically designed for the hair and the consumer using it.

Learn about active surfactant matter in the Professional Natural Hair Care Formulation Course.