How to Wash Your Hair After Keratin Treatment Step By Step

Written by Camelia Smith
Reviewed by Kayla Davis

Updated on

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instructions on how to wash hair after keratin treatment

Washing hair after a keratin treatment is about keeping your hair clean while preserving the treatment. This guide aims to walk you through the precise steps and considerations to ensure you get the most out of your keratin treatment, particularly when it’s time to reintroduce your keratin-treated hair to water and shampoo.

Why do you need to handle washing keratin-treated hair with care?

Understanding Keratin Treatment

A keratin treatment is a procedure where liquid keratin and preservative solutions are applied to hair strands. This treatment seals the hair cuticles with keratin, a protein naturally found in hair and nails, to reduce frizz and make the hair appear straighter and more refined. Some keratin treatments, like Brazilian hair straightening (Brazilian Blowout), may contain Formaldehyde or its derivatives to help lock the hair in its smoother state. The effect of keratin treatments can last for up to 3 months, depending on your aftercare routine – particularly your shampoo.

Importance of your shampoo and hair washing technique

Shampoo is a hair cleansing product that removes dirt, oil, and product build-up from the scalp and hair. A shampoo can significantly impact the integrity of a keratin treatment. The cleansing agents (surfactants) that remove impurities from the hair and scalp can also inadvertently strip away the protective keratin layer applied during the treatment, especially if they are harsh or not pH-balanced.

Besides the shampoo, your hair washing technique, how you detangle your hair, and how you dry it can all play a crucial role in preserving your keratin treatment.

That’s why, in this guide, I will show you how to wash your hair after a keratin treatment using the correct washing techniques and hair products. I will also give some exclusive tips from my experience performing keratin treatments on my clients and close friends.

So, let’s dive in.

how to wash hair after keratin treatment or Brazilian Blowout with step by step instructions

1. Wait 72 Hours Before Your First Wash

Wait 72 hours (3 days) for your first wash after a keratin hair treatment. Waiting 72 hours allows the keratin solution to bond to the hair effectively. Washing your hair too soon, like within 24 hours or 48 hours, could disrupt this bonding process, preventing the keratin from properly sealing and diminishing the desired effects.

After applying the keratin solution, the hair is straightened using a flat iron. The applied heat helps seal the keratin and sets the hair in its new, smoother shape. The 72-hour waiting period allows the hair to achieve its results, says Lana Grand, a celebrity hairstylist and owner of Los Angeles-based salon Petite Mason.

From my experience, I have noticed that early external interference, like washing or even tying your hair up, could introduce kinks or waves that might become semi-permanent. The 3-day wait aims to maximize these benefits.

However, in the evolving world of hair treatments, there are now versions of keratin treatments that are “same-day wash”. Same-day wash keratin treatments, also known as 24-hour keratin treatments, are formulated differently than traditional ones, allowing for a quicker bonding process. After the same-day wash treatment, you can wash your hair 24 or 48 hours afterward.

2. Use a Sulfate-Free and Salt-Free shampoo With Keratin Infusion

Sulfate-free and salt-free shampoos remove dirt and buildup without stripping your hair, while micro keratin infusion in the shampoo progressively enhances the effect of the keratin treatment.

Sulfate in shampoo acts as a surfactant to bind to oils and contaminants, similar to soap. It is a chemical that reduces surface tension in liquids, allowing them to mix or spread more easily. Often found in shampoos, sulfates help create lather and effectively clean oils and dirt from hair.

The reduction in surface tension by surfactants, particularly sulfates, can significantly affect the keratin treatment coating on hair. The strong cleaning ability of sulfates can interfere with the coated keratin bonds, causing them to break down faster than intended. The change in surface tension can also increase water penetration into the hair shaft during washing. Excess water can cause the hair to swell, further stressing and potentially compromising the keratin bonds.

Salt (Sodium Chloride) can also be drying for hair. Like sulfates, salt is sometimes added to shampoos to aid cleansing.

That’s why using a shampoo that does not contain sulfates and salts is crucial.

Here are the sulfates and salts you need to watch out for:


  • Sodium Lauryl Sulfate
  • Sodium Laureth Sulfate
  • Sodium Chloride

I’ve been doing keratin treatment for years, and the one shampoo and conditioner set I always use and recommend to my clients and friends is the Arvazallia Advanced Hair Repair Moisturizing Set.

best shampoo to use after keratin treatment for washing hair

Arvazallia Advanced Hair Repair Moisturizing and Conditioner


3. Use Lukewarm Water to Wash Your Hair

The best water temperature to wash hair is lukewarm, which is typically around 30°C to 38°C (86°F to 100°F). This temperature range is gentle on both the hair and scalp and helps to effectively remove dirt and oils without stripping natural moisture or causing damage.

Too hot water can strip the hair of the keratin coating applied during the treatment. Heat causes hair cuticles to open up, allowing the keratin to wash out more easily, thus reducing the longevity and effectiveness of the treatment.

If the keratin treatment is applied over colored hair, hot water can accelerate the fading of hair dye. Using water that’s too hot can lead to increased dryness and frizz, which is counterproductive given that one of the primary goals of a keratin treatment is to reduce frizz and enhance smoothness.

4. Apply Conditioner After Shampooing

Conditioners help to replenish moisture, ensuring the hair remains soft and hydrated after shampooing.

Even with sulfate-free shampoos, shampooing can strip some moisture from the hair. Conditioners usually have ingredients that help to smooth and seal the hair cuticle. This complements the action of keratin treatments, ensuring the hair remains smooth, shiny, and less prone to frizz.

Shampoos, even mild ones, can alter the hair’s pH. Conditioners usually help to bring the hair back to its natural pH level, ensuring it remains healthy and resilient.

Additionally, conditioners assist in detangling the hair, making it easier to comb or brush in the shower. Smooth detangling reduces the risk of breakage, which is crucial for maintaining the integrity of the hair after a keratin treatment.

5. Detangle With a Wide Tooth Comb

Detangling hair that has undergone a keratin treatment is a delicate process. That’s why you must use a wide-tooth comb to detangle while your hair is still saturated with conditioner.

After a keratin treatment, the hair structure has been altered, making it smoother and straighter. While this process fortifies the hair, it also means it can be slightly more vulnerable to mechanical damage, especially during the initial post-treatment days. A wide-tooth comb, gentler than a regular brush or fine-tooth comb, minimizes the risk of snapping or breaking hair strands during detangling.

I use a wide-tooth comb as part of my hair-washing routine regularly. I find it easier to detangle my hair from the bottom up. I can easily undo knots and tangles to avoid ripping through my hair.

Applying conditioner and using a wide-tooth comb helps distribute the product evenly throughout the hair. Conditioner also helps the spaced-out teeth of a wide-tooth comb glide more easily through the hair as the conditioner provides lubrication and slip. The slip reduces friction on the hair shaft, which can lead to cuticle damage, frizz, and split ends.

Remember, the primary aim of a keratin treatment is smoothness and frizz reduction, so any action that can potentially induce frizz must be mitigated.

Tugging or pulling on wet, freshly keratin-treated hair can weaken the bonds formed during the treatment. Using a wide-tooth comb on conditioned hair reduces the chances of this happening, ensuring the longevity and effectiveness of the keratin treatment.

6. Rinse Thoroughly

Thorough rinsing is necessary to prevent conditioner buildup and stickiness in the hair. Leaving conditioner residues on the hair can result in product buildup over time. This buildup can weigh down the hair and make your keratin-treated hair feel greasy and sticky.

Rinse the conditioner out with pure water until the water runs clear.

7. Do a Final Rinse With Cold Water

A final rinse with cold water helps contract the hair cuticle, making it flatter and more aligned. A flattened cuticle increases the hair’s shine and helps keep the keratin coating intact.

Cold water helps in preserving the structural integrity of the keratin treatment. Minimizing potential damage and keeping cuticles sealed indirectly ensures that the benefits of the keratin treatment last longer.

8. Gently Towel Dry

Gently towel-drying keratin-treated hair prevents roughening of the hair cuticle, which can disrupt the keratin coating on the hair strands.

Hair, especially when wet, is more vulnerable to mechanical damage. Aggressively towel drying, like rubbing or wringing, can lead to breakage, frizz, and lifting of the hair’s cuticles.

For gentle drying, you must use a microfiber towel on keratin-treated hair. Microfiber towels can absorb a significant amount of water, making drying quicker and more efficient than regular cotton towels. The smooth structure of microfiber reduces friction against hair strands, resulting in less frizz and potential damage. Microfiber towels also have a soft texture, which is gentler on hair compared to the rougher texture of regular terrycloth towels, minimizing the risk of breakage.

the best keratin aftercare products for drying your hair after keratin treatment

Aquis Microfiber Hair Towel


The best way to use a microfiber towel on keratin-treated hair is to wrap it around your head like a turban and leave it for about 3 minutes until it absorbs all the water from your hair. Then unwrap it and allow your hair to dry naturally.

9. Air Dry Your Hair

Allowing your hair to dry naturally by the surrounding air, instead of using a hair dryer, is better because of reduced exposure to heat.

The main idea behind air drying is avoiding direct heat application. Heat styling tools like blow dryers, flat irons, or curling wands can reach extremely high temperatures. These temperatures can weaken or break down the keratin bonds formed during the treatment, thereby reducing the lifespan and effectiveness of the keratin process.

One of the lesser-discussed benefits of air drying is preserving hair’s natural texture and wave pattern. Without manipulating brushes and heat, hair finds its shape as it dries. For those with keratin-treated hair, this showcases the sleek, smooth treatment results without any additional intervention.

How to Take a Bath After a Keratin Treatment

After a keratin treatment, bathing requires extra care to protect your hair from hot water and steam.

Here’s a step-by-step guide on how to bath after a keratin treatment:

  1. Use a Shower Cap: Before you submerge in the bathtub, wear a shower cap to prevent any water or steam from coming in contact with your hair. Please note: Bath salts are common products used for bathing and relaxation. Salt is bad for keratin-treated hair as it may strip the keratin coating. Be extra cautious to protect your hair from the water if it contains salts.
  2. Avoid Hot Water and Steam: Even if you’re wearing a shower cap, try to keep the water temperature moderate. Excessive steam from hot water can penetrate the cap and affect the hair.
  3. Use Gentle Products: When it’s finally time to wash your hair, use sulfate-free and salt-free shampoos and conditioners. These products are gentler on the hair and won’t strip away the treatment.
  4. Minimize Friction: Be gentle when washing your body, face, and hair. Avoid excessive movement or friction around the hairline, leading to unintentional wetting or sweating.
  5. Careful Drying: After bathing, if any part of your hair gets wet, don’t rub the hair. Instead, gently pat it dry with a microfiber towel or an old t-shirt to minimize friction.
  6. Avoid Hair Products: For the first few days post-treatment, steer clear of hair gels, sprays, or other products. They can affect the setting of the keratin treatment.
  7. Watch the Humidity: After bathing, make sure the bathroom is well-ventilated to reduce humidity buildup. High humidity can melt the keratin coating from your hair and make the keratin smell.
  8. Keep Your Hair Straight: Ensure your hair remains straight and untucked behind the ears while sitting. Keeping it in its natural position after the bath will prevent unwanted kinks or bends.
  9. Post-Bath Routine: Once you’re done with your bath and your hair is dry, if you notice any bends or slight waves, use a blow dryer on a cool setting or a flat iron on low heat to gently straighten them out.

How Often to Wash Hair After Keratin Treatment?

Wash keratin-treated hair only once a week. Limiting the frequency of hair washing is essential to prolong the treatment’s effects. However, if your hair type and lifestyle necessitate more frequent washing, there are ways to do so without compromising the treatment’s benefits.

Keratin-treated hair washing frequency based on hair type and lifestyle:

Hair Type / Lifestyle Frequency / Tips
Greasy/Oily Hair Wash 2-3 times a week if your hair feels greasy after a keratin treatment. For in-between washes, consider using a dry shampoo that is safe for keratin-treated hair to absorb excess oil and freshen the roots.
Dry Hair Stick to washing your hair once a week if it feels dry and brittle.
Active Lifestyle If you have an active lifestyle that results in sweating, like frequent workouts, you may need to wash your hair more often. In such cases, try rinsing with water and using conditioner on the lengths of your hair without necessarily shampooing every time. This way, you’re refreshing your hair without stripping away the keratin.

Can You Use Dry Shampoo After Keratin Treatment?

Yes, you can use dry shampoo on keratin-treated hair. It’s a good option for absorbing excess oil and freshening up the roots between washes, which helps extend the longevity of the keratin treatment. However, choosing a dry shampoo free from sulfates and alcohol is essential to ensure it doesn’t compromise the treatment’s effects.

Here are the best dry shampoos for keratin-treated hair we recommend.

Why Does Hair Smell Bad When Washing After a Keratin Treatment?

Keratin contains proteins and other chemicals. When the hair is wet, these chemicals, which are still attached to the hair’s surface, become soluble and dissipate until the hair is completely dry.

Just allow yourself plenty of ventilated space to disperse the smell, or mix essential oil with your shampoo to mask the odor.

Read more: How to get rid of smell after keratin treatment.

How Many Washes Does a Keratin Treatment Last?

A keratin treatment can last for up to 20 washes, assuming you wash your hair once a week. Given that the treatment lasts up to 3 months (about 12 weeks), that’s 12 washes plus, give or take, another 8 washes as and when needed.

How to Make Keratin Treatment Last Longer

To make your keratin treatment last longer, you must adopt a hair care routine involving sulfate-free and keratin-infused hair products, gentle handling, and styling techniques.

It would help if you also made small lifestyle changes, like avoiding heavy workouts in the first few weeks and sleeping on a silk pillowcase.

To learn more, check out our articles on how to make keratin treatment last longer (aftercare tips).

To Wrap It Up:

Good planning and the right set of hair products make washing your hair after a keratin treatment easier and hassle-free.

To summarise:

  • Wait 72 hours for your first wash
  • Avoid hot water
  • Use sulfate-free shampoo and conditioner
  • Apply conditioner to the hair. Not to the scalp
  • Detangle with a wide-tooth comb
  • Use a friction-free microfiber towel
  • Do a final rinse with cold water
  • Do not blow-dry. Air dry instead
  • When bathing, keep your hair out of the water
  • Use dry shampoo in between washes
  • Avoid staying in humid spaces
  • Wash your hair only once a week


  1. Lana Grand, celebrity hairstylist quote on Oprah Daily.

About the Author

Camelia SmithCamelia Smith

Camelia Smith can color hair, perform keratin treatments, bleach hair, and even cut curly hair. She is our go-to person whenever we have hair treatments and styling questions.

She's also currently training as a freelance makeup artist and is passionate about helping others feel beautiful in their skin. When she's not writing or doing hair, she's usually spending time watching British period dramas.