11 Best Shampoos for Keratin-Treated Hair

This article is all about the best shampoos to maintain your keratin hair treatment for longer.

The beauty of keratin treatments

If you’ve ever battled frizzy hair and unmanageable strands, you know the transformative power of a good keratin treatment. And yes, I know it sounds dramatic, but trust me—it’s a total game-changer. A keratin treatment doesn’t just give you smooth, sleek hair—it simplifies your whole hair care routine. Suddenly, you can air-dry your wet hair and leave the house without using a blow dryer or straightener, knowing your strands will dry glossy and frizz-free. But there’s a small catch: you must use the right shampoo to maintain the effects of the treatment.

Here, I’ll take you through the best shampoos for keratin-treated hair, breaking down which ones to choose based on your specific hair type—whether you’re looking for a clarifying shampoo, or a hydrating shampoo, you’ll find the best sulfate-free formula that won’t compromise your keratin treatment results.

Why Special Shampoos Are Crucial After a Keratin Treatment

After you’ve had your keratin treatment, your stylist will always recommend using a sulfate-free shampoo to preserve the smooth, frizz-free results. Believe me, this isn’t just a sales tactic—it’s essential for keeping the integrity of your hair intact. The main ingredient in many shampoos, sodium chloride, can strip the keratin protein from your hair cuticles, leaving your hair vulnerable to moisture loss, brittle bits, and frizz. That’s why finding the best shampoo with a gentle, sulfate-free formula is a must.

I’ve learned this the hard way. A stylist once washed my keratin-treated hair with regular shampoo a month after my treatment. The results were immediate—my hair dried with frizz creeping back in, and the smoothness vanished. It’s devastating after paying for an expensive salon treatment, but the good news is that using the right shampoo can extend your keratin treatment aftercare results for months.

The Science Bit: Why Sulfate-Free Shampoos Matter

When you get a keratin treatment, the keratin protein fills in the porous spots in your hair shaft, smoothing the cuticle and sealing the strands. This process transforms unruly hair, leaving it silky and frizz-free. However, after the initial application, your hair becomes more vulnerable to damage. Using harsh shampoos with sodium chloride, benzyl alcohol, or even citric acid can strip the keratin coating away, leaving your hair back where it started.

A sulfate-free shampoo is necessary to maintain the protective layer the treatment provides. Look for shampoos that contain ingredients like cocamidopropyl betaine and natural oils like castor oil or coconut oil. These will nourish your hair without stripping the fibrous protein layer that the keratin provides.

Here’s my list of the best sulfate-free shampoos to keep your keratin-treated hair looking smooth, healthy, and frizz-free for months. I’ve personally tried these and can vouch that my keratin survived each wash unscathed. For each category, I’ve included a “save” and “splurge” option, so there should be something to suit all budgets and hair types.

Best Hydrating Shampoos for Keratin-Treated Hair

If your hair tends to be dry, you’ll need a shampoo that provides moisture without stripping away the keratin. These are my favorite hydrating shampoos for dry, damaged hair after a keratin treatment.

Save: Umberto Giannini Curl Jelly Wash

Image: Amazon

I got this in a local pharmacy when I was desperate for sulphate-free shampoo and there were only a few on offer. Despite it being marketed for curly and wavy hair, it works well for all dry, damaged hair types and provides a thorough gentle wash. It’s not groundbreaking, but a good lower-cost vegan option that works nicely to keep your lengths hydrated without leaving your scalp greasy. I like keeping a bottle of it on hand and switching it with my more expensive shampoos to help save a bit of cash.

Splurge: Bumble and Bumble Hairdresser’s Invisible Oil Hydrating Shampoo

Image: Amazon

A constant in my shower for the past 3 years, this is a truly lovely shampoo for anyone with dry, frizzy hair. It’s formulated with 6 “featherlight” oils, and hydrates without leaving the hair heavy or greasy. It gives that instant “wow” effect on the first wash, and my hair is noticeably different after using this shampoo – frizz-free, smoother, shinier, and silkier. I use it every second hair wash or any time I need my hair to behave. The conditioner is fabulous too – highly recommended.

Best Volumizing Shampoos for Keratin-Treated Hair

For those with fine hair, finding a shampoo that adds volume without compromising the smoothness of your keratin treatment can be tricky. Here are my top recommendations for thickening shampoos that work well with keratin-treated hair.

Save: Burt’s Bees Pomegranate Seed Oil Very Volumizing Shampoo

Image: Amazon

I must be honest and say I this is the only shampoo on the list I haven’t personally tried, but it has excellent reviews. It contains pomegranate seed oil and jojoba protein and promises to nourish hair while adding volume. Reviewers say it smells amazing and rave that it’s great for boosting thin hair – the price is very reasonable, I’ve got one in my Amazon basket!

Splurge: Rahua Voluminous Shampoo

Image: Amazon

This stuff is (for want of a better word) lush! Formulated with plant-based ingredients from the Amazon rainforest, this thick, sumptuous gel creates a creamy lather with a rich botanical fragrance. Although there’s a limit to how much ‘volume” a thickening shampoo can give, this definitely makes hair feel fuller and gives it a lovely shine. I love this brand and always return to it if I want a treat.

Best Color-Safe Shampoos for Keratin-Treated Hair

If you’ve got colored hair, finding a color-safe shampoo that doesn’t strip your keratin treatment is key. In theory, any sulfate-free shampoo will look after your color, but if you have a particularly vibrant or rich shade to maintain, it may be worth getting a color-care-specific formula. 

Save: L’Oreal Paris Sulfate-Free Glossing Shampoo

Image: Amazon

L’Oreal Ever Pure is worth looking into for your sulfate shampoo fix – they have a wide range with something for every hair type and much of the range comes in value bundles with conditioner and a styling product included. The Glossing collection really does what it says on the tin and will make your colored hair shine! A great, purse-friendly option.

Splurge: ORIBE Shampoo For Beautiful Color

Image: Amazon

This shampoo takes splurge to the next level, but it feels like pure luxury to use, from the first swirl of pearly liquid into your palm, to the moment the rich lather rinses away. Of course, it smells fantastic (expensive) and leaves your hair like silk thanks to baobab tree extract.  If you fancy taking your color preservation seriously, this is the shampoo for you – it even contains UV protection to prevent sun fade.

Best Scalp-Friendly Shampoos for Keratin-Treated Hair

A healthy scalp is crucial for maintaining healthy hair, especially after a keratin treatment. These shampoos are gentle on the scalp while keeping your hair smooth and frizz-free.

Save: Aveeno Apple Cider Vinegar Clarifying Shampoo

Image: Amazon

I think I’ve mentioned this product before on The Glazed. There aren’t many low-cost, sulfate-free scalp care shampoos, but this one is good. As with most Aveeno products, it’s formulated with an oat blend that will care for and nourish your scalp while cleansing. It’s gentle enough for daily use (not all clarifying shampoos can say the same) and smells pleasant – not like vinegar at all!

Splurge: Davines Naturaltech ENERGIZING Shampoo

Image: Amazon

I created an extra category because I really want to include this fantastic shampoo. The formula is laced with caffeine and enriched with “Hair Energy Complex” to help stimulate hair growth and reinforce weak hair. I enjoyed using it as it creates a cooling minty sensation as it lathers, extremely refreshing and soothing if your scalp is itchy or tight. It gives a good cleanse, without that stripped “squeaky-clean” feeling and leaves your hair soft – love it.

Honorable Mention

Pureology Hydrate Sheer Shampoo

Image: Amazon

I couldn’t wrap up this list without mentioning Pureology.  This brand goes under the radar but you will find it in many top salons in London and it is really good – the sort of shampoo where you notice a difference when you’re drying your hair. It’s all vegan and sulfate-free and the collection includes something for every hair type and concern; purple shampoo for blondes, volumizing for thin hair, hydrating for damaged strands…My favorite is the purple bottle which is super hydrating for fine hair. You only need a very small amount of shampoo for a good wash, so the bottle will last for a long time. Excellent stuff.

To Conclude

You might be tired of the old salon upsell but trust me, post-keratin treatment is the one time you do need to buy a new product to make the results last. Using a sulfate-free shampoo is absolutely essential to keep your hair smooth, shiny, and frizz-free for as long as possible. Don’t let your expensive treatment wash down the drain; invest in a keratin-friendly shampoo now and you’re guaranteed to enjoy the results for longer.

I hope my list and endless shampoo experimentation have been helpful and introduced you to a new brand or formula you love.

FINAL TIP: While you might have your products nailed at home. Don’t forget to remind hair stylists to wash with sulfate-free in the salon. I made the mistake of assuming my “salon notes” would identify my shampoo needs and this cost me big time. A quick reminder can save your keratin.

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