salon-treatment
Keratin smoothing treatment
A chemical smoothing service that coats and reshapes the hair's surface behaviour, sealed in with heat, to reduce frizz and drying time.
Indicative cost
£120.00–£350.00 per treatment
Downtime
None to the hair, but many formulas require you to avoid washing or tying hair for 24–72 hours.
Typical course
One treatment, repeated when it wears off
Keeping it up
Every three to five months
How it works
A solution is applied and then sealed with a straightening iron at high temperature. The result is a smoother cuticle and reduced volume, which relaxes gradually as the hair grows and is washed.
What a session actually involves
Hair is clarified, the solution applied section by section, then blow-dried and flat-ironed in fine sections. It takes a long time and can smell strong; salons should be well ventilated.
What people usually consider it for
- Frizz
- Dryness
- Curl definition
- Dullness
This reflects what the treatment is commonly used for — not a claim that it will work for you.
When it may not be suitable
- You are pregnant or breastfeeding
- You have asthma or airway sensitivity
- You have a sensitive or broken scalp
- Your hair is already severely compromised by bleaching
This list is not exhaustive. A qualified practitioner should assess you before any treatment.
Things to weigh up
- — Ventilation is a genuine safety issue
- — It loosens curl pattern — not what you want if you wear your curls
What the evidence looks like
Effective for frizz and manageability. The important safety question is formaldehyde or formaldehyde-releasing ingredients, which are regulated and can irritate the eyes and airways — ventilation and product choice matter.
Questions worth asking first
Ask specifically whether the formula releases formaldehyde, what the ventilation is, and whether the stylist wears a mask.
What tends to sit alongside it
- Sulphate-free shampoo
- Hair mask
- Heat protectant
Others people compare it with
Treatments and devices are listed for information only. Nothing here is medical advice, a diagnosis, or a promise of a result. Suitability depends on your health, skin and the specific device or practitioner — always check with a qualified professional first.