MissLJBeauty

 Let’s face it, keeping blonde hair looking bright, soft, and cool-toned is no easy task. Being a fake blonde is hard, by the way. Between hard water, sun exposure, and my fitness lifestyle, my hair faces constant challenges. Blonde hair fades fast, turns brassy even faster, and needs regular toning to stay fresh. Brassiness and yellow undertones are the bane of my life. It's a lot of work to look naturally blonde, don't you know. 

I have tried more of this type of product than I would like to admit. The hype on this one was too much to ignore, and that's why I decided to put the famous Kérastase Blond Absolu Bain Ultra-Violet Shampoo to the test. It’s a luxury purple shampoo from Kérastase’s award-winning Blond Absolu range, designed to neutralise brassiness, brighten blonde tones, and nourish bleached or highlighted hair. You might remember I have reviewed their shampoo and loved it, but that doesn't mean I will love this one, so I had to give it a really good test. 

After using it for several months, I can honestly say it’s become one of my favourite shampoos for blonde hair. Here’s my full, honest review, including results, tips, and how it compares to other toning shampoos.

Quick Take

If your blonde hair is losing its brightness or looking yellow, this Bain Ultra-Violet purple shampoo is a total game changer. It tones, hydrates, and strengthens all in one go,  leaving hair glossy, smooth, and cool-toned without any hassle. 

Best for: Platinum, ash, highlighted, bleached, or grey hair
Texture: Lightweight violet gel with rich, creamy lather
Scent: Fresh, floral, and salon-like
Price: Around £28–£32 for 250ml
How often to use: Once or twice a week
Verdict: One of the best purple shampoos for blonde hair,  powerful yet gentle, deeply nourishing, and totally worth it.

Why You Need to Use Purple Shampoo

Blonde hair doesn’t stay perfect on its own,  no matter how good your colourist is and mine is excellent.  Over time, sunlight, heat styling, and even minerals in tap water cause blonde tones to shift. That’s when the yellow and orange hues start creeping in and your once-cool blonde starts to look a little tired.

A purple shampoo acts as your colour-correcting step between salon visits. The violet pigments in formulas like Kérastase Blond Absolu Bain Ultra-Violet help to cancel out those unwanted warm tones, restoring balance and brightness to your hair. WE are trying to achieve that natural blonde looking perfection, not that yellow Barbie hair. Although I think modern Barbie knows how to bleach and tone. 

It’s not just about tone, though. The right purple shampoo also maintains shine, protects your colour, and prevents long-term dullness caused by pollution or product build-up.

I always say that if you’re investing in blonde hair, you should protect it properly, and a good purple shampoo is your secret weapon. It keeps your colour looking freshly toned and salon-clean, even weeks after your appointment.

In short, purple shampoo isn’t optional for blondes; it’s essential if you want your hair to stay bright, glossy, and beautifully cool-toned. Let's face it, we pay a lot to be blonde in the first place. 

What Makes the Kérastase Blond Absolu Range So Special

The Kérastase Blond Absolu line is all about repairing and reviving blonde hair. It’s not just about removing brassiness,  it’s about caring for hair that’s been bleached, coloured, or lightened, so basically my hair. 

The Bain Ultra-Violet shampoo uses ultra-violet pigments to cancel out unwanted yellow tones, while edelweiss flower extract protects against pollution and hyaluronic acid delivers deep hydration.

The result? Hair that feels silky, strong, and clean,  with that salon-fresh blonde tone we all crave.

What Hair Types Does Kérastase Blond Absolu Bain Ultra-Violet Work On?

The great thing about Kérastase Blond Absolu Bain Ultra-Violet is how versatile it is,  it suits most blonde and grey hair types because of its lightweight yet nourishing formula.

It works beautifully on:

• Bleached or highlighted hair – helping to strengthen fragile strands while neutralising brassiness.

• Natural blonde hair – to brighten and maintain cool tones without over-toning.

• Silver or grey hair – to remove dull yellow hues and restore a clean, icy shine.

• Fine or medium hair types – thanks to its soft, gel-like texture that doesn’t weigh hair down.

• Wavy or straight hair – it lathers evenly and rinses clean, leaving hair smooth and fresh.

If you have very dry, coarse, or curly hair, I’d suggest pairing it with a deeply hydrating mask like Cicaflash or Masque Ultra-Violet to lock in moisture after toning.

This shampoo is ideal for anyone who wants to keep blonde hair looking bright, soft, and cool-toned, whether your colour is salon-fresh or naturally sun-lightened.

How to Use Bain Ultra-Violet Purple Shampoo

1. Wet your hair thoroughly.

2. Apply a small amount and work it into a creamy lather.

3. Leave on for 2–5 minutes, depending on your desired tone. The longer you leave it, the more pigment your hair will take. But remember, this is strong so always worth a strand test unless purple hair is your thing. 

4. Rinse well.

5. Follow with Kérastase Cicaflash conditioner or Masque Ultra-Violet for extra nourishment or any really hydrating mask 

My tip: Alternate this with Bain Lumière,  it’s a gentle, hydrating cleanser that keeps your hair soft and shiny between toning washes.

Ingredient Breakdown: What’s Inside Kérastase Blond Absolu Bain Ultra-Violet

I always like to peek at what’s actually inside a product, because ingredients tell you everything about how it performs. The Kérastase Blond Absolu Bain Ultra-Violet isn’t just pigment and perfume; it’s a clever hydrating and toning formula designed for blonde, bleached, and silver hair.

 Key Actives

• Hyaluronic Acid – Attracts moisture into the hair fibre to keep strands plump, hydrated, and strong.

• Edelweiss Flower Extract – Protects against UV rays, pollution, and free radicals while adding smoothness and shine.

• Ultra-Violet Pigments – These tone-correcting pigments neutralise yellow undertones to keep blonde hair bright and cool.

Supporting Ingredients

• Sodium Laureth Sulfate – A mild cleanser that removes oil and product build-up, creating that satisfying lather.

• Citric Acid – Balances scalp pH and helps close the hair cuticle for extra shine.

• Cocamidopropyl Betaine – A coconut-derived foaming agent that softens the formula and keeps it gentle.

• Glycerin – Adds slip, moisture, and a silky finish.

• Fragrance & Colourants – Give the shampoo its signature clean scent and the rich violet tone that makes the product so effective.

Are There Any Ingredients to Watch Out For?

This isn’t a completely sulfate-free shampoo, but the cleansing agents are gentle enough for most hair types. If your hair is very dry, pair it with Bain Lumière or a nourishing conditioner from the same range to maintain balance.

It also contains fragrance, which gives that signature Kérastase scent is fresh and slightly floral. I love it, but it’s worth noting if you’re sensitive to scented products.

 My Take

The ingredient list perfectly explains why it performs so well. The blend of violet pigment, hydrating actives, and antioxidants gives you that salon-clean tone and softness in one wash. It’s not just a purple shampoo, it’s a treatment for blonde hair that truly nourishes while it tones. Which if youare blonde you know this is hard to find in a toner. 

Violet vs Blue Shampoo – What’s the Difference?

It’s a common question! The difference lies in which undertones you want to correct:

• Violet shampoo (like this one) is perfect for light blonde, platinum, or grey hair because violet cancels yellow tones.

• Blue shampoo is better for darker blondes or light brunettes, as blue neutralises orange or copper tones.

Since my blonde is on the lighter, ashy side, violet is perfect for me; it keeps my tone cool and bright. But if you’re a warmer honey blonde or bronde, blue might be better suited.

Tip: Don’t mix violet and blue shampoos in the same wash; alternate them if needed to balance tone naturally. They both leave pigment behind, so you need to be careful. 

Pros & Cons

Pros

• Instantly neutralises brassiness and yellow tones

• Hydrates and nourishes with hyaluronic acid and edelweiss flower extract

• Strengthens fragile, bleached hair

• Keeps blonde hair bright, soft, and cool-toned

• Lightweight formula, easy to rinse

• Works beautifully on blonde, grey, or silver hair

• Provides long-lasting colour protection and shine

 Cons

• Higher price point than drugstore purple shampoos

• Overuse may create a faint lilac tint (washes out quickly)

• Works best when alternated with Bain Lumière or a hydrating shampoo

Kérastase Blond Absolu vs Bain Lumière

People often ask which one to choose. The truth is: both.

• Bain Lumière is your everyday hydrating shampoo that boosts shine and moisture.

• Bain Ultra-Violet is your anti-brass purple shampoo that tones and brightens.

I use Bain Lumière during the week and Bain Ultra-Violet once or twice for colour correction — the perfect combo for keeping blonde hair fresh, strong, and glossy.

My Blonde Hair Care Routine

I have said it before, I will say it again. Being blonde is hard going. First, you pay a fortune to super super-talented hairdresser. Which, let's face it, it's hard to find your perfect hairdresser in the first place. You want that colour to look good day in, day out. No matter how good your hairdresser is, this is up to you and how much work you want to put in. I am a mountain bike athlete as well as beauty blogger so my hair and body is pushed to the extreme so is my hair. 

Here’s what I use to keep my blonde looking healthy, bright, and strong:

• Shampoo: Kérastase Bain Ultra-Violet (once a week) and Bain Lumière or Olaplex no4 for hydration

• Conditioner: Cicaflash or Masque Ultra-Violet for deep nourishment, or Olaplex no5

• Treatment: Olaplex No.3 once a month to repair and protect

• Styling: Leave-in serum for shine and heat protection, and the occasion hair oil. 

This combination keeps blonde hair soft, bright, and free from brassiness, even with my active outdoor lifestyle.

My Kérastase Blond Absolu Review – Real Results

So let's start at the start. I have bleached blonde fine hair. My hair might be fine but there is a lot of it. I mountian bike so I have my hair in a helmet all the time, and sometimes it might even get mud in it. So if anyone can really test this its my poor hair. I have tried so many of these shampoos over the years. I have had great results and awful ones. Yes I have been the victim of the purple rinse before. But what blonde hasn't? 

From the first wash with this, I noticed a visible change. The brassy yellow undertones disappeared, and my hair instantly looked cleaner and brighter. After two or three washes, my blonde had that cool, ashy finish I usually only get at the salon. It is almost too good. 

I leave it on anywhere from 5 - 10 minutes, depending on how brassy I have let my hair get. Then rinse out for a full 2 minutes, making sure there's no purple left in the water. Then add a doo mask for a few mins and boom. My hair is back to salon quility. 

The texture feels silky, and it creates a luxurious violet lather to which is just kinda fun. It leaves my hair soft and fresh without feeling stripped. It’s the perfect mix of anti-brass toning and deeply nourishing care.

Even after outdoor training or days under a helmet, my blonde still looks healthy, shiny, and cool,  not dull or dry. I’m genuinely happy with the results. I can 100% recommend this, and I will rebuy again and again, and that's something coming from me. 

Where to Buy & Cost-Per-Use

You can shop Kérastase Blond Absolu Bain Ultra-Violet Purple Shampoo (250 ml) from trusted UK retailers like:  Tip: Remember to look for a discount code or wait for a sale to make it cheaper, there are so many around at the moment. 

• Kérastase Official UK – £28.50 RRP

• LookFantastic – often with 10–20% off codes

• Sephora UK – £30 approx.

• Amazon UK – prices vary, but always check it’s sold by Kérastase or an authorised partner

Cost-per-use estimate:

I use this shampoo once a week, and my 250 ml bottle has lasted around six months, roughly 25–26 washes. That works out at just over £1 per use, which is incredible value for a luxury purple shampoo that tones, hydrates, and extends your salon colour.

Considering a single salon toner can cost £20 +, this bottle more than pays for itself. The texture is rich, the pigment is powerful, and you only need a small amount each time.

If you’re on a budget, LookFantastic and Sephora often run bundle deals on the full Kérastase Blond Absolu range (Bain Lumière, Cicaflash, and Masque Ultra-Violet), which can save you a few pounds while keeping your whole routine consistent

Kérastase Blond Absolu vs Olaplex No.4P

I’ve also used Olaplex No.4P, and while it gives slightly stronger toning, I find Kérastase Blond Absolu Bain Ultra-Violet far more hydrating and gentle on my hair. Olaplex can feel a little intense if you use it too often, whereas Kérastase keeps my blonde bright and soft week after week.

If you want deep repair and heavy toning, go for Olaplex No.4P.

But if you prefer a luxury, nourishing purple shampoo that tones and adds shine, Kérastase wins for everyday use.

Frequently Asked Questions About Bain Ultra-Violet Shampoo

Is Kérastase Blond Absolu Bain Ultra-Violet good for bleached hair?

Yes,  it’s formulated for bleached, highlighted, or lightened hair. It strengthens and hydrates while neutralising brassiness for a bright, clean blonde.

Does it dry out hair?

No. The hyaluronic acid and edelweiss flower extract make it incredibly moisturising and gentle. It’s one of the few purple shampoos that actually leaves hair soft and nourished.

Can I use it on grey or silver hair?

Absolutely! It brightens dull tones, adds shine, and removes any yellowing, ideal for silver or white hair.

How long before I see results?

Most people see results after one wash. After two or three uses, the colour tone is noticeably cooler and brighter.

What’s the difference between Bain Ultra-Violet and Bain Lumière?

Bain Ultra-Violet tones and removes brassiness, while Bain Lumière hydrates and adds shine. Use both for a complete blonde care routine.

Can I use it with Olaplex or other treatments?

Yes! It works perfectly alongside Olaplex No.4 and No.5, and also pairs beautifully with the Kérastase Masque Ultra-Violet for weekly deep care.

Will it make my hair purple?

Only if you leave it on too long. Keep it to 2–5 minutes, and you’ll achieve a clean, cool tone without over-pigmenting.

How often should I use it?

Use once or twice per week depending on how quickly your hair turns brassy. Alternate with a hydrating or repairing shampoo like Bain Lumière.

Final Thoughts

I’ve tested countless purple shampoos, and Kérastase Blond Absolu Bain Ultra-Violet is easily one of the best. It offers professional results at home toning, strengthening, and hydrating in a single step.

Neutralises brassiness and yellow tones
Deeply nourishes and strengthens bleached hair
Adds long-lasting shine and smoothness
Protects against pollution and UV damage

If you’re serious about maintaining a cool, bright blonde, this Kérastase Blond Absolu shampoo is the one to beat. 

Written by Laura Martin, qualified makeup artist and skincare therapist at MissLJBeauty.com