I know you are all shocked by this, but I am not a natural blonde. I know, I know, You are all flabergusted. It must be my dark roots that give it away.. But I’ve had blonde hair in one form or another for years, highlights, full head, balayage, you name it, and if you’re blonde, You know the struggle is real! Keeping blonde looking fresh, bright, and healthy is a full-time job. The wrong shampoo can leave it dull, dry, or, worst of all, brassy.
I have natural mousy brown hair, although that was so long ago I hardly remember it. My hair is long and fine, but there is so much of it. My lovely new hairdresser is half stylist and half miracle worker, and I leave the salon looking and feeling like a million dollars. But this is where her responsibility ends and mine begins. You blondies feel me. We spend a fortune to look this good, right, and the maintenance is no joke. I am always trying to find the holy grail product that will make my blonde pop and give me time in my routine.
So, at the end of the day, with so many people talking about this product, I had to buy it right. Im talking Kérastase Blond Absolu Bain Lumière Shampoo and give it a proper test for you all.
This is the hydrating, shine-boosting one in the Blond Absolu family, and it’s designed to care for blonde hair without weighing it down, which spoke to me as a fine-haired gal. I also use the Kérastase Blond Absolu Bain Ultra-Violet Shampoo about twice a month to keep brassiness fully at bay, so I’ll talk about how they work together, too and let me know if you want a full Violet shampoo review too.
Super Quick Take
Price: ~£25–£30 (250ml)
Pros: Hydrating, lightweight, brightens blonde hair, adds shine, smells gorgeous, protects against brassiness
Cons: Premium price tag, needs Ultra-Violet version for heavy brassiness
Best For: Natural blondes, highlighted hair, balayage, bleached hair that needs hydration without heaviness
What is Kérastase Blond Absolu Bain Lumière?
Bain Lumière is part of the Kérastase Blond Absolu range. This the brand’s first-ever haircare line created specifically for us blondes. Kérastase, if you’re not familiar, is a French luxury haircare brand known for blending salon-grade science with indulgent, sensorial products. Blond Absolu was developed to tackle the two biggest blonde hair struggles: keeping colour vibrant and keeping hair healthy after lightening.
Bain Lumière is the “clear” shampoo in the line, so unlike the purple Bain Ultra-Violet (which is packed with violet pigments to cancel brassiness), this one is all about hydration, protection, and that fresh-from-the-salon glow. It gently cleanses without stripping, nourishes with high-performance ingredients, and leaves hair feeling light, bouncy, and luminous.
It’s ideal for anyone who doesn’t need weekly toning but still wants to maintain brightness and shine between colour appointments, whether you’re a natural blonde, highlighted, or rocking a balayage.
Overview of Blond Absolu Products
The range has two main shampoos:
Bain Lumière – hydrating and shine-boosting for all blondes
Bain Ultra-Violet – purple pigment formula to tone and neutralise brassiness
There’s also a conditioner, hair mask, heat-protecting serum, and an intense fortifying oil — all designed to work together for hydrated, healthy blonde hair.
Key Ingredients in Kérastase Blond Absolu Bain Lumière
If you're like me, you've got your eye on what's really in your shampoo. If you have read anything I write about product, you will know I love to actually know what's going in in each bottle. especially when it's on the pricier side items. So I dug in, and here’s what makes Bain Lumière such a hydration hero:
Hyaluronic Acid – A moisture magnet that strengthens and plumps the hair fiber, helping your blonde look and feel more resilient and less prone to breakage. Verified by Kérastase themselves as a cornerstone for “hydrating illuminating” care.
Edelweiss Flower Extract – Known for being antioxidant-rich, it protects your blonde from daily pollution and environmental stress while softening the cuticle.
Gentle Cleansing Agents – Bain Lumière uses mild surfactants like Sodium Laureth Sulfate, Coco-Betaine, and Cocamide MIPA to wash away dirt and build-up without stripping your hair dry.
Hyaluronic Acid + Antioxidant Blend – While it doesn’t contain purple pigment, the blend helps purify hair from dulling buildup and pollution, keeping your blonde brighter and more reflective.
And rest assured, this isn’t a greasy, silicone-laden formula. It feels light in your hair, leaving you with fresh, bouncy strands, not coated or weighed-down locks. We as blondes know light formulas that are not harsh are really important to the longevity of our locks.
Benefits of Using Blond Absolu Shampoo
For me, the big stand out wins in this forulam are:
Lightweight moisture – my hair feels hydrated but not flat
Shine boost – blondes can often look a bit dull, but this adds a glossy finish
Softness – my hair feels silky after washing
Colour protection – helps keep highlights looking bright for longer
Hydration and Care for Blonde Hair
Blonde hair, especially if bleached, can be prone to dryness and breakage. Its the bane or our life, right? I know, excuse the pun, but I had to. Bain Lumière is perfect for giving hair a drink without heaviness. The hyaluronic acid really does help. We love it for our skin, so hair is no differnt. My ends feel softer and less brittle, and my hair doesn’t get oily quickly. Which, if you're a gym person like me, this is key.
How to Use Kérastase Blond Absolu Shampoo
I reach for Bain Lumière about three times a week, and it’s my go-to for keeping my blonde fresh and hydrated between toning sessions. About twice a month, I swap it out for the Bain Ultra-Violet (the purple one) to knock out any brassy tones.
Here’s exactly how I use it for the best results:
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Wet hair thoroughly – I make sure my hair is completely soaked so the shampoo can spread evenly.
- Foam up- This is really important take a small about of the shampoo and foam it in your hands first.
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First cleanse – then I take that small amount and work it through from roots to ends. This first wash is all about removing any product build-up, oils, or pollution from the week. So really think about root cleansing here.
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Rinse completely – Don’t rush this step; you want every bit of the first wash gone.
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Second cleanse – Another small amount (which has been foamed in your hands), this time focusing on massaging the scalp again and letting the hyaluronic acid and edelweiss extract work their magic. I leave it on for a minute or two to really let the hydration sink in. Let it do the work here.
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Rinse and follow with conditioner or mask – I usually pair it with the Blond Absolu Cicaflash conditioner or Masque Ultra-Violet if I’m toning that day.
Top tip: Always double cleanse with this shampoo. The first wash lifts away build-up, the second gives the active ingredients time to actually do their job.
Can Kérastase Blond Absolu Help Remove Brassiness?
No not on its own, it keeps brassiness at bay for mild cases, but if your blonde is heading into yellow territory, pair it with Bain Ultra-Violet for a deeper tone correction. I do this every couple of weeks, and it keeps my blonde perfectly cool-toned. It has no pigment so there is no way of it changing the colour but it does help prolong your colour and stop fading.
How the Shampoo Protects Against UV Damage
Keeping blonde hair bright isn’t just about toning; it’s also about shielding it from sun stressors. On Kérastase’s site, they talk about how Edelweiss Flower Extract protects colour-treated hair from daily pollution and oxidative damage, which includes UV and environmental stress. That’s basically your blonde wearing a little sunscreen for your strands. If I understand it right.
In short, it doesn’t rely on chemical UV filters, but those antioxidant-power ingredients actively defend your hair's colour and health if you’ve been out in the sun, whether you’re beach-bound or just gardening on a sunny day. But this is not a sunscreen, so I wouldn't rely on this for UV protection.
Cost & Where to Buy
Blond Absolu Bain Lumière is definitely a salon-quality shampoo
On the official Kérastase UK site, 250 ml is around £29.60, with a 500 ml refillable bottle priced at £50.40. You can get it online stores like LookFantastic, Boots, Sephora UK, and Allbeauty typically stock it between £24–£28. Depending on sales and discount codes. AS I always say, check for discounts and sales.
I bought my big bottle from Amazon when they had a sale. Yes, its expensive, but it lasts a long time I've had mine for around three months. You need very little each wash. But start with the small bottle to make sure. you like it.
Is Kérastase Blond Absolu Worth the Investment? My Review
For me, yes. It’s one of the best shampoos for blonde hair in the UK, especially if hydration and shine are your main concerns. The results last, my hair feels healthier, and I genuinely notice less breakage. I would say when I first got this shampoo, I was blown away. Initially, it lathers great, feels nice on the hair and does what a shampoo should do. But it was the after effect that my hair looks silky and smooth. I found myself reaching less for the purple shampoo. Meaning I was getting longer between needing to use it. It seems to have restored my hair in a way i didn't think anyone could. I still love my Pureology strength cure , but this one is just lighter and better for me at the moment. It is gentle and deeply nourishing at the same time. My split ends have even become less noticeable to me. Did I mention even as a woman who works out at least 4 times a week, I could go an extra day without shampooing? Well, this is new in my world and very welcome.
I team it with a good conditioner, but it teams with any, to be honest. I have used it with high-end and drugstore products, and it gives the same results. Will I keep buying this? Hell yes, and as a blogger, I think that is the ultimate compliment. Plus, even my hairdresser asked what I had changed up as my condition had got better, I mean, from the words of a queen in hair. How can I not have this in my collection now?
Yes, I still use my Olaplex no 3 about every 6 to 8 weeks, too. I love that product, but you all know that if you have read my full review No 3 on that.
Final Thoughts
If you’re a blonde looking for a hydrating, shine-enhancing shampoo that won’t weigh your hair down, this is worth every penny. Pair it with the purple Bain Ultra-Violet shampoo, and you’ve got the ultimate blonde care routine covered.
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