If you want the sleekest, most manageable and frizz-controlled hair of your life, there's only one word you need to know: Keratin.
Keratin is "the main protein of the hair, skin and nails", says Jez Barnett, founder of .
"Keratin makes up to 91 percent of hair and contains 16 different amino acids, with cysteine being the most important one as it creates the sulphur bridges in hair that give it it's internal strength."
In fact, it even has the royal seal of approval and is loved by none other than Meghan Markle.
According to Meghan's former hairstylist, Theonie Kakoulli at Nicky Clarke, it's the secret behind Meghan's sleek ends.
She told PEOPLE: "Meghan came to see me at least twice for keratin treatments. It’s great for people with naturally curly hair like Meghan, it takes the frizz out and makes it more manageable — she said it made a real difference."
Here's everything you need to know about Meghan's go-to treatment...
What is a keratin treatment?
A keratin treatment forms a coating over the hair to mimic smoothness and shine. But despite the name, keratin isn't the main ingredient.
"Hair cannot accept more than around one per cent extra keratin in a treatment without losing the moisture-protein balance", says Jez. "This balance is essential for the hair to retain it's strength, suppleness and malleability."
Therefore most keratin treatments use other sources of protein to repair the hair including corn, vegetable, soy and wheat. But really create that smooth, sleek and shiny finish, in-salon keratin treatments rely on more than just proteins.
"Early keratin treatments contained formaldehyde or methylene glycol, but these were banned due to concerns over health and safety, says Jez.
"Modern formulations use ingredients like a glyoxylic acid-carbocysteine mix, which strengthens, repairs, smooths and straightens."
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People often associate keratin treatments with straightening, and while it does do this, modern formulas are based on rebuilding and strengthening the hair just as much.
Ideal candidates are those with curly, wavy, frizzy or unruly hair; "essentially anyone who doesn't enjoy their natural movement", says Jez.
"For clients who find their hair too thick and therefore takes too long to style, a major bonus post-treatment is that it's so much quicker and easier to manage."
What happens at a keratin treatment appointment?
Different products and salons have different methods, so make sure to do your research before booking your appointment.
Most will start off with a gentle clarifying shampoo to prep the hair, before applying the keratin (some will dry the hair first, others will leave it damp) and then leave it on for anywhere between 15-60 minutes depending on the product.
"The older treatments were then dried in and ironed, whereas the newer, more advanced treatments are lightly rinsed off (to remove excess product) before being dried and ironed", says Jez.
Lorraine Rose, Hairdresser and Founder of , says "flat irons are taken through the hair in small sections to close down the cuticles and lock the keratin into the hair."
The shiny, glossy and lightweight result at the end of the appointment should then remain for up to five months, or until the treatment naturally breaks down.
Kerastraight keratin treatment review
With exceedingly thick, mid-length hair that is growing slowly out of its bob hairstyle, GLAMOUR's Jen Garside decided to try the new Kerastraight treatment to tame her unruly mane.
I'd always wondered whether a keratin treatment would help with my hair woes, but was nervous about the time involved and any potential after-effects. However, much like new tanning innovations, the Brazilian blow dry has come on leaps and bounds since first coming to UK salons - and the Kerastraight Ultimate Treatment is living proof.
The lovely and talented Ben at explained the benefits of the new Ultimate keratin treatment, and I was completely sold on the fact I could leave the salon without worrying about tying it up into a ponytail hairstyle and causing a kink.
The increased hydration levels offer the highest levels of simultaneous repair and straightening. The new customisable formula claims that it can target not only thick, curly hair like mine, but also work on "resistant, very curly and Afro-Caribbean hair".
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After a clarifying shampoo, the Kerastraight treatment was combed through each part of my hair in segments individually, then left to work for 45 minutes before being lightly washed. If you have extremely curly hair, the product is blow-dried into your hair at this stage. As I wanted the straightening and thinning effects, reducing styling time but still meaning I can use my favourite curlers when desired, I skipped this stage and opted for a light blow dry before having the product straightened into my hair with the special Kerastraight irons.
Each segment is ironed up to ten times, depending on the coarseness of your hair in that area - it can vary wildly across your head due to styling, colour and cut - during which a vapour rises into the air. To prevent any other customers thinking your hair is being damaged, Trevor Sorbie place you in a private room at this stage.
Once straightened, your hair looks amazing but feels as if you've left your conditioner in. At this point, there's a waiting time before washing out the product and styling as normal. Being lazy, I opted for the full salon-experience and had it washed out before Ben effortlessly blow dried it straight. It took approximately half the time it normally does, and was poker-perfect with just a hair dryer, no need for straightening.
If you're looking for super-sleek, stress-free summer hair without reaching for the straighteners, a keratin treatment is your answer. Two days on, I have had my hair in up-dos, down, exposed to rain and not needed to touch my GHDs once! It also seems to have lightened my hair slightly, a golden blonde bonus I can certainly work with...
What's the post-care routine following a keratin treatment?
Back in the day, hair would have to be left completely alone for three days. No washing, no hair ties – you couldn't even tuck it behind your ears!
"With , a major plus is that the client can shampoo their hair anytime after just 30 minutes", says Jez.
But with other brands you may still have to wait a day or two before washing to allow the treatment to settle.
When you DO wash your hair, Guest Artist, Lisa Whiteman says to avoid sulfate-free and sodium chloride shampoos and conditioners. "Keratin is actually broken down by sulphates in shampoo quite quickly", she says. So if you want your treatment to truly last, use these recommended products:
2. (both £19.00)
3. (both £6.99)
Are there any downsides to getting a keratin treatment?
If completed correctly, a keratin treatment should have no negative effects on the hair. Over time, the keratin will break down and the hair should return to its natural state.
As for your hair colour, Lisa recommends getting your regular refresh after the treatment, saying "the hair can be slightly discoloured after the effects of ironing".
You may also want to add a hydrating hair mask into your routine to keep your hair in peak silky condition.
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