What Is a Keratin Treatment? How It Works, Safety, Results & Cost
PURE KERATIN on 4th Nov 2026
Quick answer: A keratin treatment is a semi-permanent smoothing treatment. A keratin-based formula is applied to clean, dry hair, then sealed in with a blow dryer and a flat iron. It reduces frizz, adds shine and makes hair faster to dry and easier to style. It is not permanent: the effect fades gradually over about 3 to 5 months, depending on your hair and how you care for it.
Keratin treatment at a glance
- What it does: smooths frizz, adds shine, cuts drying and styling time
- How long it lasts: usually 3 to 5 months
- How long it takes: around 2 to 4 hours, depending on hair length and thickness
- Where: in a salon, or at home with a kit, a blow dryer and a flat iron
- Best for: frizzy, wavy, curly, thick or hard-to-manage hair
- Check before you buy: that the formula is formaldehyde-free (see Is a keratin treatment safe?)
What is a keratin treatment?
Keratin is the protein your hair is naturally made of. Colouring, bleaching, heat styling, sun and hard water wear it down over time, which leaves the hair cuticle rough and open. That rough surface is what you see as frizz and dullness.
A keratin treatment, also called a keratin smoothing treatment or Brazilian keratin treatment, coats the hair with a keratin-rich formula and uses heat to seal it onto the hair fibre. The cuticle lies flatter, so hair reflects more light, tangles less and resists humidity. "Brazilian Blowout" is often used as a general name, but it is actually the brand name of one specific salon treatment.
How does a keratin treatment work?
Whether it is done in a salon or at home, the process follows the same four steps:
- Clarifying wash. A clarifying (purifying) shampoo removes oils, silicones and product build-up, so the formula can attach to the hair.
- Application. The hair is dried, divided into sections and the treatment is brushed on strand by strand, avoiding the scalp.
- Blow-dry. The hair is dried completely with the product in it.
- Flat iron. Thin sections are flat-ironed several times. The heat activates the formula and seals it into the hair.
The smoothing effect does not come from keratin alone. Most formulas combine keratin with active smoothing ingredients that are activated by heat. Which active ingredient a product uses is what makes the biggest difference to the result and to safety, so it is worth reading the label (more on that below).
Want to do it yourself? Follow our step-by-step guide to keratin treatment at home.
What does a keratin treatment do for your hair?
- Less frizz, even in humid weather
- More shine and a softer feel
- Faster blow-drying and easier styling, often cut by half or more
- Smoother, more manageable curls and waves, or straighter hair with higher-strength formulas
- Fewer tangles and less breakage from daily brushing
What it does not do: it does not permanently change your hair's structure like a chemical relaxer, it does not repair split ends, and it does not make hair grow.
Types of smoothing treatments compared
| Treatment | How it works | Typical result | Typically lasts |
|---|---|---|---|
| Keratin treatment | Keratin formula sealed in with heat | Smooth, frizz-free, straighter depending on strength | 3 to 5 months |
| Express keratin | Lighter formula, shorter application | Less frizz, softer hair | 4 to 6 weeks |
| Hair botox | Deep-conditioning filler treatment, no strong smoothing agent | Fuller, softer, shinier hair; little straightening | 2 to 4 months |
| Nanoplasty | Smoothing treatment based on amino acids and other agents | Smooth, straighter hair | 3 to 5 months |
| Chemical relaxer | Permanently breaks the hair's internal bonds | Permanently straight (until regrowth) | Permanent on treated hair |
For a detailed comparison, read keratin vs. hair botox vs. Brazilian blowout.
Is a keratin treatment safe?
The safety of a keratin treatment depends on its ingredients, not on the keratin itself. The main one to avoid is formaldehyde. Some smoothing products contain formaldehyde, or ingredients that release it when heated by the flat iron. The fumes can irritate the eyes, nose and throat, and formaldehyde is classified as a carcinogen. That is why more and more people choose formaldehyde-free formulas, and why it is worth reading the full ingredient list before you buy any smoothing treatment.
Safe-use checklist, whatever product you use:
- Read the full ingredient list (INCI) before you buy, and avoid formaldehyde.
- Work in a well-ventilated room and wear gloves.
- Keep the product off the scalp and away from skin cuts or irritation.
- Follow the product's timing and flat-iron temperature exactly.
- Do a strand test first, especially on bleached or very fragile hair.
- If you are pregnant, breastfeeding or have a health condition, ask your doctor before any chemical hair treatment.
- If you feel unwell during or after any chemical hair treatment, stop and seek medical advice.
Our formulas
Pure Keratin treatments are formulated without formaldehyde. You can find the full ingredient list on each product page. Learn more about our formaldehyde-free formula.
Does a keratin treatment damage your hair?
A well-formulated treatment applied correctly should leave hair feeling healthier, not weaker. Damage usually comes from three things: too much heat (flat-ironing at a higher temperature than recommended, or too many passes), a formula that is too strong for the hair type, and repeating treatments too often. Already bleached or very fragile hair needs a lower strength and a strand test first. Most people should wait until the previous treatment has mostly washed out, often around 3 months, before repeating it.
How long does a keratin treatment last?
Usually 3 to 5 months. The result fades gradually as you wash your hair, so how long it lasts depends on:
- Your shampoo: sulfate-free shampoo makes the biggest difference
- How often you wash: fewer washes per week means longer results
- Your hair type: porous or bleached hair absorbs more but can lose it faster
- Swimming: chlorine and salt water shorten the result
Read more: how long a keratin treatment really lasts.
How long does a keratin treatment take?
Around 2 to 4 hours in total. Short or fine hair is at the lower end; long, thick or very curly hair takes longer because there are more sections to flat-iron. At home, set aside an afternoon the first time.
How much does a keratin treatment cost?
In a salon, a keratin treatment typically costs from about $150 to $500 or more, depending on the city, the salon and your hair length. An at-home kit costs a fraction of that and can be a good option if you are comfortable using a blow dryer and a flat iron. See our full breakdown of keratin treatment costs, or browse our at-home keratin kits.
Can you do a keratin treatment at home?
Yes. At-home kits use the same steps as a salon treatment: clarifying shampoo, application, blow-dry, flat iron. The keys to a good result are choosing the right strength for your hair, working in thin sections and following the instructions exactly. Our at-home guide walks you through every step.
Which keratin treatment is right for your hair type?
| Your hair | Suggested strength |
|---|---|
| Fine, coloured or fragile hair, or you want to keep your natural wave | Free to 5% |
| Natural blonde or fine European hair | 5% |
| Wavy, thick or frizzy hair | 5% to 8% |
| Very curly, coily or Afro hair | 8% to 12% |
Still unsure? Try our keratin calculator or see the full keratin treatment range.
Keratin treatment aftercare
- Wait before the first wash for the time given in your product's instructions, and avoid tying, clipping or tucking hair behind your ears during that period.
- Use a sulfate-free shampoo and conditioner. See which shampoo to use after keratin.
- Use a weekly hair mask to keep hair soft.
- Rinse after swimming in chlorine or salt water.
- Planning to colour? Read keratin and hair colour: what comes first.
Who should (and shouldn't) get a keratin treatment?
Good candidates: anyone with frizzy, wavy, curly or thick hair who wants smoother, shinier hair and less styling time, without permanently straightening it.
Think twice if: your hair is already very fine and flat (it can lose volume), you want to keep strong curls (choose a low strength or skip it), your hair is severely damaged from bleaching, or you are pregnant or have a health condition (ask your doctor first).
Keratin treatment FAQ
Is a keratin treatment good for your hair?
Done correctly with a suitable formula, yes: it smooths the cuticle, reduces frizz and makes hair easier to manage, which means less daily heat styling. Problems usually come from overheating, overly strong formulas or treating too often.
Does a keratin treatment straighten hair?
It smooths hair and removes frizz. Higher-strength formulas give a noticeably straighter result, especially on curly hair, while lower strengths keep more of your natural wave. It is not a permanent straightener like a relaxer.
Can I wash my hair after a keratin treatment?
Yes, but wait for the time stated in your product's instructions before the first wash, then use a sulfate-free shampoo. Read how soon you can wash after keratin.
Is keratin the same as a Brazilian blowout?
"Brazilian blowout" is often used as a general name for keratin smoothing, but it is the brand name of one salon treatment. Both smooth and de-frizz hair; formulas and ingredients differ from brand to brand.
How often can you get a keratin treatment?
Usually every 3 to 5 months, once the previous treatment has mostly washed out. Repeating too often increases the risk of dryness and breakage.
Can men get a keratin treatment?
Yes. It works the same way on any hair; shorter hair simply needs less product and less time. See keratin treatment for men.
Written by the Pure Keratin team, specialists in formaldehyde-free keratin hair treatments since 2017. Last updated: November 2026.
