There's a moment, just after a keratin blowdry, when the guest stands up from the chair and the hair carries a particular weight. It feels denser. It falls flatter. The shine is there but not yet fully settled. What happens in the days and weeks after that moment decides whether the treatment was worth booking. Aftercare carries the second half of the work.
We apply the keratin at the bowl, and then the work continues under the guest's own hands for twelve weeks. So this is the briefing we send home in writing, the way we'd talk it through across the chair at No. 386 Paisley Road West.
The first seventy-two hours are the bond setting
The treatment needs uninterrupted time to bond with the shaft. Most credible UK salon guidance puts that window at seventy-two hours, and what we see at the chair matches it. For three days, the hair stays dry. No washing, no rain caught without a hood, no gym session that ends in damp roots. No ponytails or grips. No tucking behind the ears.
Anything that puts a bend in the hair while the bond is still pliable leaves a mark that lasts weeks. A soft scarf is fine, draped rather than knotted. Sleeping flat on the back is fine. Hair worn loose is fine. Everything else can wait until the third day clears.
Sulphates, salt, and what to read on the back of the bottle
After the seventy-two hours, the shampoo matters more than most guests realise. Sulphates strip the keratin layer the treatment has laid down. Sodium chloride does the same, and it turns up in cheaper formulas more often than the label front suggests. The instruction we send guests home with is to read the ingredient list and avoid sodium lauryl sulphate, sodium laureth sulphate, and sodium chloride.
A sulphate-free shampoo, run through twice a week, sometimes three, is what the keratin wants. Daily washing is not the right rhythm for this hair. Co-washing, in our experience, is unnecessary. The shaft is already conditioned to within an inch of itself. For guests who also colour, the further question of whether the hair is asking for protein or moisture comes up at every visit, and reading what colour-treated hair needs is the companion piece for that diagnosis.
Drying, brushing, and the pillow you sleep on
A microfibre towel, or a clean cotton t-shirt, is the correct tool for getting the water out. A terry towel roughens the cuticle and starts the keratin lifting in patches. Squeeze, blot, wrap. Don't wring.
Brush with a wide-tooth comb while the hair is still damp, working from the ends upward. A round brush comes back at the blow-dry stage, not before. If a silk or satin pillowcase is in the house, use it. We've seen the difference at the eight-week mark on guests who do and guests who don't.
For the chemistry of what the treatment is doing inside the shaft, we wrote a separate piece on what a keratin blowdry does to the hair shaft, which is the companion read to this one.
Heat tools at a ceiling of one-eighty
The blow-dryer is fine. Straighteners and curlers are fine, with the dial set no higher than 180°C. A heat protectant goes on first, every time. Most modern tools mark 200°C as their default. Turn the dial down before you turn it on.
If you used to iron the hair every morning, the keratin should make that habit redundant. The shaft is already smoothed. The dryer alone gets you there. The treatment does the work the iron used to do.
Pools, sea water, and the holiday question
Chlorinated pools and sea water both strip the keratin faster than ordinary shampoo. The protocol for a holiday is to saturate the hair with fresh water before going in, apply a leave-in oil, and wear a cap if a cap is acceptable. After, rinse with fresh water immediately. For colour clients asking the same question about tap water, we wrote separately on hard water and colour fading in Glasgow.
A week on the Mediterranean coast will take some shine off a keratin blowdry. Two weeks will take more. Guests planning a long trip do better to book the appointment for the week they fly home, not the week they fly out.
Weeks eight to twelve, when the diary opens
Through the first eight weeks, very little needs doing. Wash on the schedule above, dry with the right tools, sleep on the right fabric. The hair sits where you put it. The dryer works in half the usual time. A guest with shoulder-length hair who used to fight for thirty minutes most mornings is looking at closer to fifteen.
Around week eight, the shine starts to dim a notch. By week ten, the ends are usually telling you the keratin is thinning. By week twelve, the next treatment goes in. That's our window. Some salons push to sixteen weeks. In our experience on a Glasgow head of hair, twelve is where the shaft still has enough integrity for the next application to bond cleanly.
This isn't a hard rule. A guest who keeps to the aftercare strictly can stretch past twelve. A guest who swims twice a week, or who washes daily, will land closer to ten. The protocol decides.
The full menu, with what the blowdry and treatment services include, sits on the services page.
To put the next keratin blowdry in the diary, or a first one, an appointment is the way in. The chair, on Paisley Road West since 2020, is by appointment.