Zoltan Hair · Mayfair · A Down treatment
Straightment Demi
Volume down, frizz gone, hair that dries close to straight on its own and behaves through rain, gym and weather. Four to six months, and it grows out with no line.
See prices & bookAll Down treatmentsby length and density
frizz 80–90%
soft grow-out, no line
Before anything else
Everything you do to your hair costs it something. Including nothing.
This is the part most salons leave out, so I would rather you had it first.
Think about a bag you actually like
Not the one in the box — the one you have carried every day for three years. Rained on. Put down on the floor of the tube. Stuffed too full. Keys rattling around in it. It does not look like it did in the shop and it never will again. That is not neglect. That is what carrying it every day does.
Your hair has been with you far longer
The lengths on hair past your shoulders are often four, five, six years old — grown, then worn, every single day since. Rain. Sun. Hard London water. A hairband. A brush pulled through it when you are late. A towel. A pillow. A blow-dry. An iron at 200 degrees because it would not sit down otherwise. None of it dramatic, all of it adding up — and unlike skin, hair does not repair itself. What happens to it stays happened.
And you never notice you are doing it
Nobody stands at the mirror thinking that is damage. You put it up because it is windy. You go over it again because one bit will not sit down. You rub it dry because you are late. It is automatic, it is every day, and it is a couple of thousand small decisions a year that nobody counts. A treatment is the one thing on that list you actually decide to do — which is why it feels like the risky one, and why it gets all the blame.
So the honest question is not “will this damage my hair?”
Everything does. The question is what you spend, and what you get back for it.
Yes, it has a cost
I will not pretend otherwise. It changes the structure of the hair, and that is the whole reason it works.
But it is not only a cost
The cuticle gets sealed, so the hair holds moisture instead of losing it. It reflects light properly, so it looks and feels better than it did — and that is genuine, not a trick of the blow-dry. Most people's hair is in better condition after a well-chosen treatment than before it, because the thing being repaired is the damage they were already doing.
And the daily spend drops
Hair that lies down does not get gone over five times with an iron. Hair that is not fighting you does not get brushed hard when you are rushing. Hair that dries smooth does not need thirty minutes of heat every morning. For a lot of people the damage they stop doing is larger than the damage I do.
It only works if there is something to spend
That is my part of it — choosing chemistry the hair can actually afford. Some hair has already spent more than it had, and for that hair the answer is no, or not yet. You will get told which one you are.
What I promise
The three numbers, honestly
An honest range, not a headline. If a salon tells you "board straight" for a treatment in this family, they are selling you something else.
Salon time
2 – 4 hours
Two hours for fine or wavy hair at any length. Longer as density and length increase — up to four hours on thick, curly, extra-long hair. Timed to the hair, not to a clock on the wall: porosity and history change how fast it develops.
How much it takes out
Frizz 80–90% · Volume 60–80% · Curl 50–70%
Frizz is what largely disappears, and volume comes down with it — for most people the bulk is the real complaint, not the curl. Curl itself is softened, not removed — the hair dries close to straight on its own and behaves in weather, but this is not a pin-straight treatment and I will not pretend otherwise. If pin-straight is the goal, you want Straightment Permanent.
How long it lasts
4 – 6 months
And more importantly, how it ends: it softens gradually and washes out. There is no demarcation line, no shelf where treated meets new growth, and no bad month five. That is the reason people re-book this one rather than escalating to something permanent.
What it actually does
Not what the marketing says. What happens to the hair.
It works inside the hair, not on the surface
The active penetrates the cortex and loosens the hair's internal links, and then heat forms new ones in the new position. That is why it outlasts a blow-dry — a blow-dry only ever moves hydrogen bonds, which water breaks again in the first shower. This reaches further in, and holds for months.
Demi-permanent means it fades, not that it stops
Demi is about time, not about how much of your head is treated — the whole head is done. Not every bond is broken and reformed, so your hair keeps a degree of its own character and its own bounce. Those untouched bonds are exactly why it grows out softly instead of leaving a hard shelf where treated meets new. (Treating one section only — a fringe or hairline — is a different service.)
The cuticle closes behind it
The process opens the cuticle to let chemistry into the cortex, then closes it again. A closed, smooth cuticle reflects light — which is where the shine comes from, and why hair often feels better afterwards than it did before.
In the chair
What actually happens on the day
No mystery, and nothing that should be a surprise once you are sitting in it.
1 · Read and clarify
I read the hair — pattern, frizz, damage, and what has already been done to it — then wash with a clarifying shampoo to strip product, oils and the mineral build-up London water leaves behind. Chemistry cannot get into hair that is coated, and this step is why treatments fail elsewhere.
2 · Apply and develop
The active is applied section by section and left to develop. It works into the cortex and begins loosening a proportion of the disulfide bonds. Timed to the hair, not to a clock — porosity and history decide how fast it moves, which is why the same service takes different lengths of time on different heads.
3 · Blow-dry and shape
Dried in, with tension and direction. This is where the shape you are going to live with is decided — the hair is being taught where to fall, and a blow-dry done badly here shows up for months.
4 · The iron — sealing it in
Thin sections, controlled heat, several passes. The iron is not there to make it look straight for the afternoon: the heat drives the reaction that locks the new shape into the bonds and flattens the cuticle down over it. Too cool and it will not hold; too hot, too many passes, or sections too thick and you are buying damage. This is the step that separates a good result from an expensive one.
5 · Nothing is rinsed out — it leaves with you
No neutraliser, and no rinse at the basin. A neutraliser belongs to thio chemistry — perms, relaxers, rebonding — where bonds are broken and then oxidised back closed. Here the heat is what forms the new links, so there is nothing to neutralise and nothing to wash away. The treatment goes home in your hair and carries on settling, which is exactly why what you do in the next two days matters.
6 · Your first wash — at home, by you
The first wash is yours to do, and it is simple: warm water, a mild shampoo, no scrubbing, and dry it smooth rather than leaving it to dry in a bend. Forty-eight hours is what I recommend; the same day is possible and I will tell you plainly which yours is before you leave. Blow-dry and finish are included, so you go out able to see exactly what you have bought.
What you actually get
Frizz gone
Through rain, humidity and the gym. London never drops below about 66% humidity and peaks at 85% in December — this is a year-round problem here, not a summer one.
5 minEasy, not just quick
Styling time drops sharply — most people go from a daily fight with a hairdryer and straighteners to a rough dry and out. The bigger change is how little effort it takes: it behaves without technique, product or patience.
Condition improves
Because you stop attacking it with a 200°C iron every day. Over a year that is hundreds of passes the hair never takes.
No hard line
It softens rather than stops. There is no bad month five where a shelf appears — the reason people re-book this rather than escalate.
Who it suits — and who it does not
Ideal
W8 – C5 · natural to lightly processed
Wave through to defined curl, frizzing in humidity, where the complaint is manageability rather than a wish to be poker straight. Frizz at F2–F3 responds best, because there is a visible problem to remove.
Possible, with care
C4 – Z3 · or damage at D
Tighter patterns and coarser hair can take this, but the strength and timing have to be matched precisely — and on damaged lengths I will often treat roots at full strength and the ends far more lightly.
Usually no
DD – DDX · heavily bleached or over-processed
Where the cystine has been oxidised to cysteic acid the damage is irreversible. A result can be forced in; it will not hold and the hair pays for it. The honest answer here is often recovery first, or a lighter treatment instead. Do not write it off on my say-so from a web page — this is exactly what a consultation is for, and I would rather look at it than guess.
Book a mini consultation →No surprises
Things I would rather you heard from me than found out in the chair
None of this is in anybody else's brochure. It is all true, and knowing it in advance is the difference between a surprise and a plan.
It will smell
Anything heated to 200 degrees smells — think of food. Your own mousse or styling product on there smells too. Some treatments frankly smell like wet dog for a day. I work next to an open window and it clears, but I am not going to pretend it does not happen.
Some treatments shift your colour
Not all, but some will lift or warm what is already on your hair. If that applies to yours I will tell you before we start and we plan around it. I spent years as a colourist, so this is a conversation rather than a surprise at the mirror.
It can go flat
Certain hair looks bouncy for a fortnight and then sits down. I can usually work around it — leaving the roots alone, choosing a lighter strength, changing where I place the tension. But only if I know beforehand that volume matters to you. Say it at the consultation, not afterwards.
Damage is the thing we are trying not to do
These are chemical services and they are not free. Done properly on suitable hair the trade is small and worth it. Done wrong, or on hair that has already been through too much, it is breakage — which is exactly why sometimes the answer is no.
The first two visits, we are getting to know each other
This is the most useful thing on the page, and the thing almost nobody says out loud.
The first appointment is a learning appointment
I do not know your hair yet — and I do not know you. I know the chemistry; I do not yet know how yours takes it, what the last person left in it, or the life it has to survive: your mornings, your training, your travel, how much time you will honestly give it. So I work carefully the first time, and careful means slightly under rather than slightly over. That is deliberate. I can always add more next time. I cannot take it back out.
The second visit is where it comes together
By then I have seen how your hair behaved, how long it held and what it did in week six — and you have lived with it, and can tell me what you actually thought. Now I can push further or pull back with something real to go on. If the first result is good but not quite it, that is not a failure. That is the information.
My “perfect” and your “perfect” may not be the same thing
I might look at your hair and see a result I am pleased with — even, healthy, doing exactly what the chemistry should do. You might look in the mirror and want it flatter, or curlier, or with more root left in. Neither of us is wrong. We are looking at different things.
So tell me, in your own words
Tell me what you want it to look like before we start, and tell me afterwards if it is not that. Not to complain — so I can adjust it next time. The clients whose hair I get right consistently are almost always the ones who told me what they actually wanted on visit two.
And the honest end of it: maybe I am not the right stylist for you. I am not saying I am — I am trying, and by the second visit we will both know. I would rather give you that sentence than a guarantee nobody could honestly make.
Whatever it is called elsewhere, this is the category.
Keratin treatment · Nanoplastia · Taninoplastia · Cysteine · Escova definitiva · Progressive blow-dry · Hair smoothening
Those are brand names and market names for a family of chemistry, not seven different things. Each one is a particular reducing agent at a particular pH, sold under a particular label — and the label tells you nothing about whether it suits your hair.
Straightment Demi is my own system. I carry the range rather than one supplier's line, and the actives, strength and timing are chosen against your reading on the day — pattern, frizz and damage — not poured out of whichever bottle the salon has a deal on.
Ask me about glyoxylic acid and you will get the regulators' evidence rather than a sales line. If you would rather read it all up first, the complete guide to smoothing and straightening is free and holds nothing back.
The terms, plainly
The same glossary appears on every treatment page here, so the language means the same thing wherever you read it — with what each term means for this particular treatment underneath.
pH
The acid-to-alkaline scale. Hair sits at about 4.5–5.5, slightly acidic. Alkaline products swell and open the cuticle so chemistry can get in — more change, more cost to the hair. Acid products close and smooth it — gentler, shinier, less penetration.
On Straightment Demi: acid-side. The cuticle is coaxed rather than forced. Alkaline chemistry would give a stronger result and cost the hair more — that trade is the entire point of a demi.
Disulfide bonds
The strong, permanent sulphur-to-sulphur links. They give hair both its strength and its bounce. Hydrogen bonds, by contrast, are weak and temporary — broken by water and heat, which is why a blow-dry drops in the rain.
On Straightment Demi: a proportion are loosened and re-set by heat, not all of them. The ones left alone are why it grows out softly with no line and no shelf.
Porosity
How easily hair absorbs and holds water and chemicals. High porosity means a raised, damaged cuticle: it soaks product up fast and processes quickly and unevenly. Low porosity is resistant and needs more time.
On Straightment Demi: sets the strength and the timing. Porous or previously treated hair takes it faster and unevenly — which is why the ends are often treated more lightly than the roots.
Bounce (elasticity)
The ability to stretch and spring back, governed almost entirely by disulfide bond health. You can impose a shape on almost any hair. You cannot impose bounce — it has to be earned from healthy bonds.
On Straightment Demi: reduced deliberately but not removed. On very fine hair I go lighter, because losing root lift is a genuine risk.
Reduction and neutralisation
The two-step chemistry of any perm or relaxer. Reduction breaks the bonds so the hair can be reshaped; neutralisation reforms them in the new shape and locks it in.
On Straightment Demi:not how this works. Heat forms the new links, so there is no neutralising step and nothing is rinsed at the basin — it leaves in your hair.
Processing time
Timed to the hair, not to a clock on the wall. Porosity, texture and history all change how fast a treatment develops.
On Straightment Demi: two hours on fine or wavy hair, up to four on thick, curly, extra-long hair.
Colour
When to do your colour
The single most common mistake, and the one that costs the most to undo. Colour and smoothing chemistry pull against each other — the order matters, and it is not the same order for every version of this treatment.
If we use a keratin or protein system
Colour first
Colour before the smoothing, or on the same day immediately before it. Once the cuticle is sealed down, colour struggles to get in and takes unevenly — and a fresh colour put on top of a sealed treatment tends to sit on the surface and fade fast.
If we use an acid or plastia system
Colour after
Acid plus heat can lift the hair one to three shades and pull warmth through a toner. Colouring first means watching it change in front of you. Here we treat first, let it settle, then colour to the shade you actually end up with.
Bleach and highlights
The real conversation
Bleach is not colour — it is damage with a colour result. How much, how recently and how high a lift decide whether this treatment happens at all, and at what strength. Tell me the bleach history before anything else, including work done years ago. It is still in there.
Which system yours needs is decided at the consultation, from your reading — so the honest answer to "should I colour first?" is ask me before you book the colour, not after.
Skin test
I do not routinely do one for straightening or perming, and there is no blanket UK requirement for these services — it is the product manufacturer and the insurer that drive it, not the law. Where a specific product calls for one, I will tell you and we will do it. Hair colour is a different matter: there it is effectively mandatory.
Strand and elasticity testing
Also not routine. I read the hair at the consultation and again on the day. Where I judge it necessary, I will say so before we start — and we test before anything else happens, rather than finding out halfway through.
What actually protects the hair
Knowing what has already been done to it. Colour history, previous chemistry and how it was cared for tell me more than any test — which is why I ask for the history before I ask what you want.
Making it last
The first 48 hours
Recommended, not compulsory. Most salons tell you 72 hours as though it were law. Leaving the shampoo out for 48 hours gives the best result — but washing the same day is possible, and I will tell you honestly whether yours needs the wait. What matters more is keeping it loose: no tight ties, no clips, no tucking behind the ears for long stretches, because a mechanical bend set now can stay.
What you wash it with
You do not have to give up lather. The rule is not "no sulphates ever" — it is no harsh ones. A gentle sulphate cleanser is fine; the heavy strippers (high-strength SLS and SLES, salt-loaded formulas) are what shorten the result, and washing every single day shortens it further. Two or three washes a week with something mild is the whole of it.
Not sure about the one in your shower? Send me a photo of the ingredient list and I will tell you whether to keep it. That offer stands whether you booked with me or not.
London water
Thames Water classifies its entire supply as hard. Peer-reviewed work shows chemically treated hair binds considerably more mineral than untreated hair — because processing creates the sites minerals attach to — and that build-up stiffens the fibre and costs you the finish. A periodic chelating wash addresses it.
Read further
Where this sits in the wider family
Straightment Demi draws on chemistry from more than one tradition. These are the free guides covering each of them — what is in them, where they came from and who they suit.
Keratin & protein family
Every semi and demi-permanent smoothing treatment that coats and fills the hair rather than permanently restructuring it. Keratin, Brazilian blow dry, cysteine, smoothening.
Open the guide →Brazilian & plastia
Brazil's answer to its own formaldehyde crackdown — nanoplastia, taninoplastia and their siblings, built on organic acids rather than aldehydes.
Open the guide →Japanese & Chinese systems
Shukumo kyosei, permanent thermal reconditioning, and the acid-heat systems developed for hair too damaged for alkaline work. Where you go if Demi is not strong enough.
Open the guide →Rebonding family
Asia's structural straightening tiers, up to permanent pin-straight. The honest comparison point for anyone who wants more than Demi can give.
Open the guide →Korean systems
Magic straight, down perm and the Korean approach that straightens while keeping root lift — a genuinely different answer to the same problem.
Open the guide →The complete guide
Every smoothing and straightening treatment sold anywhere in the world, in one place. What is actually in it, what it does, how long it lasts and who it is wrong for.
Start here →Questions people actually ask
Will it make my hair poker straight?
No, and it is not meant to. Curl is softened by roughly half to two thirds and volume comes down with it — the hair dries close to straight on its own and behaves in weather. If you want genuinely pin-straight, that is Straightment Permanent and I would rather sell you the right one than disappoint you with this one.
Will my hair go flat and lifeless?
Volume comes down deliberately, but the hair keeps its own bounce because not every bond is reformed. On very fine hair I use a lighter strength for exactly this reason — losing root lift is a real risk on fine hair and I will say so before we start rather than after.
What happens when it grows out?
It softens and washes out gradually. There is no shelf, no hard line and no bad month five — which is the main practical difference between this and anything permanent.
Can I wash it the same day?
Often yes. Leaving it 48 hours gives the best result and is what I recommend, but same-day washing is possible and I will tell you honestly which yours is. What matters more in those first two days is keeping it loose — no tight ties, no clips, no tucking it behind your ears for hours.
Can I tie it up? Wear it up for an event?
Yes — loosely. A soft tie is fine even in the first two days; what sets a mark is anything tight, a hard clip, or hair jammed behind your ears for hours. After 48 hours you can do as you like. If there is a wedding in the diary, tell me the date and I will time the appointment around it.
How soon can I have it again?
As often as every two months, and I have plenty of clients on exactly that. Coming back while it has faded rather than vanished is easier on the hair, not harder — there is less to do each time. Four to six months is the outside edge, not the rule, and how often suits you is part of what we settle at the consultation.
Is it safe if I am pregnant or breastfeeding?
That is not my decision to make for you, and I will not pretend otherwise. What I will do is give you the full ingredient list for the exact product I would use on you, so you can put it in front of your midwife, GP or pharmacist and decide with someone qualified to advise. Ask before you book and I will send it over.
Will it work on my hair if I have had it done badly before?
Usually, and often that is exactly why people come. What I need is the truth about what was used and when, even if you do not know the brand name — where it was done and what it smelled like tells me more than you would think.
Real prices, published.
Four questions about your hair and the calculator gives you the exact price for your length and texture, and the appointment to book. No "from" prices that grow once you are in the chair.
See prices & bookCompare the Down treatmentsNot sure this is the right one? A mini consultation online is £9.95 — it is not a deposit and it does not come off the treatment, and every treatment includes a full consultation on the day at no charge.