Smoothing & Frizz Control · London
Smoothfiller: smoother, frizz-free hair in one salon visit
A demi-permanent treatment that smooths, fills and restructures your hair from the inside. Less frizz, more shine, humidity resistance – and your natural texture stays your own. Results last up to three months.
Up to 3
months of results
~90 min
approx. in-salon time
No regrowth
fades softly, no harsh line
01 What Smoothfiller is
A demi-permanent treatment that works inside the hair
Smoothfiller is Wella Professionals’ demi-permanent smoothing service – a newer take on keratin-style treatments. In a single in-salon session it smooths, fills and restructures the hair, leaving it shinier, easier to style and far more resistant to humidity. It is not a relaxer and not a permanent straightener: your waves and curls stay, they just behave.
- Fill. The active ingredient is an organic acid that fills gaps in the hair’s protein structure, where frizz and roughness come from.
- Bond. A thermal activation step – a flat iron worked through in sections – sets new, stable internal bonds.
- Restructure. Those new bonds smooth and restructure each strand from within, so the result is built into the hair, not coated on top.
02 Why clients book it
What Smoothfiller gives you
Frizz control that holds in humidity
The treatment that survives damp air, drizzle and central heating – the things that usually undo a blow-dry by lunchtime.
Smoother, shinier hair
Noticeably glossier and softer to the touch, with a polished finish that still moves naturally.
Faster, easier styling
Quicker to blow-dry and easier to manage day to day – even a rough dry comes out neater.
Your natural texture kept
Curls and waves are softened and elongated, not flattened. It refines your hair rather than replacing it.
No harsh regrowth line
Results fade gradually over the weeks. There’s no demarcation line and no awkward grown-out stage.
A gentle, low-fume formula
Eight ingredients, low fume, dermatologically tested, vegan, silicone- and fragrance-free. A comfortable service from start to finish.
03 Your appointment, step by step
What happens in the chair
- 1
Consultation & patch test
We assess your hair and goals first. A patch test is required before your Smoothfiller service, so book this in ahead of your appointment if it’s your first time.
- 2
Cleanse & prep
Hair is shampooed and dried to around 80% before the treatment goes on.
- 3
Apply & develop
Smoothfiller is applied section by section, kept off the scalp, and left to develop for about 20 minutes – no heat, no covering.
- 4
Rinse & dry
The product is rinsed out fully, then hair is blow-dried completely dry, ready for activation.
- 5
Thermal activation
Your stylist works through in small sections with a flat iron – more passes for maximum smoothness, fewer for a softer frizz-reduction finish. This is the step that locks in the result. Around 90 minutes in total for medium-length hair.
04 Colour & Smoothfiller together
Having colour done too?
Smoothfiller fits around colour rather than fighting it. You can have a demi-permanent toner straight after the treatment in the same visit, and highlights or a small regrowth touch-up can be done beforehand. For a full head of permanent colour, we’ll usually leave it a few washes after Smoothfiller. The simplest thing is to tell us your colour plans at the consultation and we’ll sequence it properly.
05 Is it right for you?
Honestly, who Smoothfiller suits
A great fit if you
- Have naturally frizzy hair – straight-but-frizzy, wavy or curly
- Spend ages blow-drying smooth only for humidity to undo it
- Want easier, faster everyday styling
- Like your texture and don’t want it straightened away
- Prefer a result that fades softly with no grown-out line
Worth a chat first if you
- Want poker-straight hair – this manages frizz, it doesn’t straighten curl
- Rarely blow-dry or style – the smoothest results show when you do
- Are sensitive to smell – some clients notice a faint odour on wet hair for the first several washes
- Have a big colour change planned – we’ll want to sequence colour and treatment carefully
06 The results
Smoothfiller at Hair Culture
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07 Before & after
The difference, side by side
Wavy, frizz-prone mid-lengths – before and after one Smoothfiller service.
Curly hair – frizz reduced and curls elongated, natural pattern kept.
08 Making it last
Aftercare
One of the best things about Smoothfiller: no fussy rules. There are no post-service restrictions – you can wash your hair whenever you like, with any shampoo. To keep it looking its smoothest for the full three months, a little gentle care helps.
Keep it smooth
Smoothing and conditioning products help maintain the polished finish between washes. Browse our take-home range:
Style it out
The result shows best when you blow-dry or style after washing – even a quick rough dry comes out smoother than it used to.
A note on the first washes
Some people notice a faint scent on wet hair for the first few washes. It settles – it’s a normal part of how the treatment works.
09 Good to know
Smoothfiller questions, answered
How long does Smoothfiller last?
Up to three months. It fades gradually with washing – there’s no harsh regrowth line, the smoothing just softens over time.
Will Smoothfiller straighten my curls?
No. It reduces frizz and softens and elongates your curls for a more polished shape, but keeps your natural pattern and movement. If you want poker-straight hair, this isn’t the service – say so at consultation and we’ll talk options.
How long does the appointment take?
Around 90 minutes for medium-length hair. Longer or thicker hair takes a little more. Your stylist will give you a realistic time at booking.
Do I need a patch test?
Yes. We require a patch test before your Smoothfiller service, so please arrange it ahead of your appointment if you’re new to the treatment.
Can I colour my hair at the same appointment?
Often, yes. A demi-permanent toner can go on straight after, and highlights or a small regrowth touch-up can be done before. Full-head permanent colour is usually best left a few washes later. Tell us your colour plans and we’ll sequence it.
Are there any aftercare restrictions?
None – you can wash your hair right away, with any shampoo. There’s no sulphate-free requirement and no waiting period.
Is it suitable for coloured or sensitised hair?
Generally yes – the activation is adjusted for coloured and sensitised hair. We’ll assess your hair’s condition at consultation and tailor the service to it.
Will my hair smell?
The product is low-fume during the service. Some clients notice a faint scent on wet hair for the first several washes – it fades as the weeks go on.
Effortless hair, every day
Book your Smoothfiller treatment with Eva or Gabby – every appointment at Hair Culture is with a senior, Sassoon-trained stylist. Not sure if it’s right for you? Start with a consultation.
Official Sassoon Professional Partner Salon since 2012 · Multi-award-winning – Trendvision, English Hair & Beauty Awards, British Hairdressing Business Awards