What Does Keratin Do for Hair? Guide to Keratin Treatments

Key takeaways (TL;DR)

• Keratin is a naturally occurring protein that your body uses to form hair, nails, and skin.



• Many in-salon and at-home hair treatments use keratin to help repair and smooth hair and add a glossy finish.



• In-salon keratin treatments can leave hair smoother and frizz-free for up to 6 months.



• At-home treatments, like L’Oréal Professionnel’s Keratin Alpha Sleek range, offer similar benefits without a trip to the salon, controlling frizz for up to 2 weeks*.

You might’ve heard of keratin treatments, especially in the salon – but what actually is keratin and what does it do to your hair? In simple terms, keratin is a protein your hair naturally contains, and it plays a big role in keeping strands strong, smooth and healthy-looking.

Over time, things like heat styling, colouring and everyday wear and tear can deplete it, leaving hair feeling rough, frizzy or a little lacklustre.

That’s where keratin-infused treatments come in. In this article, we’ll dive into keratin’s benefits for hair, break down what it really does, and how you can work it into your routine for softer, sleeker results. We’ll also look at the best keratin treatments for hair, both in the salon and at home.

What this article will cover

• What is keratin for hair?


• What does keratin do for hair?


• What does a keratin treatment do?


• What are salon keratin treatments?


• Can you do a keratin treatment at home?


• Who are keratin treatments suitable for?


• Best keratin treatments for hair

Keratin is a naturally occurring protein that your body produces and uses to form your hair, nails, and skin. Keratin is a strong protein and provides protection and support to the hair and other parts of the body in which it is found.

When hair is damaged, due to age, heat, or the use of strong chemicals, it can lose some of its keratin, making it weaker, frizzier, and less healthy than it otherwise would be. Keratin treatments and at-home products aim to ‘undo’ this damage by replenishing your hair's supply of keratin.

Because of its crucial role in the development of hair, keratin shampoos, conditioners, and in-salon treatments have become go-to methods for some people looking to revitalise dull hair.

Whether you’re in the salon or at home, there are several keratin treatment benefits. These include:

• Thicker-looking hair: Keratin treatments reinforce hair's strength, which can contribute to a fuller, thicker appearance.



• Smoother hair: A key keratin treatment benefit is smoother hair. Keratin smooths the cells in our hair, which helps to create a smoother, glossier finish.



• Quicker drying: Some people find that keratin treatments make drying their hair easier, quicker, and result in less frizz.



• Hair growth: While keratin does not make hair grow, it does strengthen hair, meaning it can reduce breakage and split ends.



• Repairing hair: Replenishing your hair’s supply of keratin can help to strengthen it, preventing and repairing some of the effects of damage from heat, ageing, and chemicals.

The best keratin treatments replenish your hair’s strength and make hair far more manageable in the short to mid-term. Some keratin treatments can make hair look straighter and reduce frizziness, meaning you can spend less time taming your hair.

What does a keratin treatment do?

As we age, our hair loses keratin, both from damage we cause (drying, styling, chemicals) and damage we can’t avoid (UV rays, our environment). This keratin loss causes pores to develop in hair, and porous hair is one of the number-one causes of some common hair nemesis – frizz, tangles, and split ends.

So, what does keratin do, exactly? It fills in these porous gaps in the hair and smooths hair cuticles. Keratin’s ability to fill in these gaps and seal the hair reduces signs of damage, contributing to a healthier, smoother and glossier finish.

Salon keratin treatments can vary, but in most cases, your stylist will apply an intensive form of keratin in small doses to sections of your hair after a thorough wash and cleanse. The intensive form of keratin used in professional treatments can have a smoothing effect on hair for up to 6 months after it’s applied (but this will vary by salon, the keratin treatments used, and your hair type and routine).

Keratin’s benefits for hair are not exclusive to in-salon treatments. At-home products, like L’Oréal Professionnel’s Keratin Alpha Sleek range, replicate some of the benefits of salon treatments without needing to pay your stylist a visit.

Like salon treatments, the Smooth Transformer Professional Smoothing Treatment for all hair types works to reprogram hair at the deepest level, resulting in 5x smoother hair and 2x less frizz*. Our at-home treatments provide up to 2 weeks of frizz control, making them a simple but effective solution for short-term hair regeneration and keratin replenishment.

*Instrumental test after 4 uses of Smooth Transformer.

You don’t have to go to a salon to experience keratin benefits for hair. The main difference between at-home keratin treatments, like L’Oréal Professionnel’s Keratin Alpha Sleek, and in-salon treatments is time.

While in-salon keratin treatment benefits tend to be higher strength and therefore last longer (most lasting for around 6 months), L’Oréal Professionnel’s at-home treatments have around a 2-week lifespan. However, it can be done from the comfort of your home, and you can save the cost of a keratin treatment in the salon.

Apart from the difference in time, the benefits are similar. When you use the Keratin Alpha Sleek range, you can expect to see:

• Up to 2 weeks of frizz control*.



• 5x smoother hair**.



• 2x less frizz**.



• Unwanted volume is controlled and smoothed for styling that takes half the time***.



• Softness and instant shine that lasts up to 5 days****.

With smooth hair that is significantly quicker to style, at-home keratin treatments offer a simple and effective alternative to salon trips. You can enjoy keratin's benefits for hair without the cost and time of a salon visit.

*Consumer test on 68 participants, 1 application/week for 4 weeks. Based on 15-day break observation.
** Instrumental test after 4 uses of Smooth Transformer.
***Instrumental tests with routine 4 times of Shampoo + Smooth Transformer + Leave-on.
****Instrumental test after 1 application of shampoo, mask & serum.

How to do an at-home keratin treatment

In order to fully unlock the benefits of our Keratin Alpha Sleek range, you’ll need to know how to do an at-home keratin treatment effectively. Here’s a simple guide on how to use our Keratin Alpha Sleek range for the best keratin treatment possible.

Step 1. Cleanse with shampoo

Begin your at-home keratin treatment with our Professional Sulphate-Free Shampoo. Once a week, lather the shampoo onto a head of wet hair until a rich foam is obtained. Allow the shampoo to sit for a moment before rinsing out.

Step 2.a. Massage conditioner in

After rinsing your hair and washing off your shampoo, massage our Smooth Transformer Professional Smoothing Treatment from the lengths to the ends of your hair (again, using once a week). Leave the treatment in your hair for between 10 and 15 minutes before gently rinsing it off.

Step 2.a. Deeply moisturise with a mask

On other wash days where you aren’t using the Smooth Transformer, keep your hair topped up with keratin treatment benefits and apply the Sleek Hair Mask evenly from lengths to tips to deeply nourish and hydrate. Leave on for 5 minutes before rinsing.

Step 3. Finish with serum

Finish your weekly keratin treatment with our Mirror Sleek Serum. Apply 2-4 sprays (for thin to medium hair) or 6-8 sprays (for thick hair) of Mirror Sleek Serum to your hair once it has been washed and towel-dried. Apply the hair serum from the lengths to the ends of your hair and do not rinse it off. The serum is heat-activated, so for the best results, dry your hair with a hairdryer, a curling or straightening iron, or L’Oréal Professionnel’s SteamPod 4.0 on it.

L’Oréal Professionnel’s keratin treatments are suitable for a range of hair types and conditions. In most cases, keratin’s benefits for hair are best suited for those with:

• Frizzy hair: One of keratin’s biggest benefits is its ability to tame frizz. If you struggle to manage frizz, then keratin treatments may be for you.



• Curly hair: If you have naturally curly hair and straighten it regularly, then keratin treatments may suit you as they can calm curls for prolonged straightness.



• Damaged hair: Damaged hair, from split ends to tangles, can be helped and restored by keratin treatments.



• Thick hair: Thick hair can be left smooth and glossy, and easier to style with keratin treatments.



• Colour-treated hair: Hair damaged by strong dyes can be restored by keratin treatments.

To find out more about your hair type and understand what haircare and treatments are best for you, try our At-Home Diagnostic Tool.

Product type	Example product	How to use
Shampoo	Keratin Alpha Sleek Professional Sulphate-Free Shampoo	Apply evenly on wet hair. Lather until a rich foam is obtained. Rinse.
Treatment	Keratin Alpha Sleek Smooth Transformer Professional Smoothing Treatment	Use Smoothing Treatment once a week after shampoo. Leave on for 10-15 minutes and then rinse off.
Serum	Keratin Alpha Sleek Mirror Sleek Serum	Apply to washed and towel-dried hair. Use 2-4 sprays for thin to medium hair, and 6-8 sprays for thick hair. Heat activated – blow dry for best results.
Hair Mask	Keratin Alpha Sleek Professional Hair Mask	Use on hair wash days of the week that you do not use Keratin Alpha Sleek shampoo. Leave on for 5 minutes and rinse.

 

If you’re looking to calm frizzy hair, keep curls in check, or add a glossy finish to hair damaged by colour or heat, then keratin treatments may be for you. L’Oréal Professionnel’s Keratin Alpha Sleek range makes it easy to enjoy keratin’s benefits for hair at home. For instantly smoother hair and a smooth, glossy finish, try the range.

Discover Keratin Alpha Sleek from L’Oréal Professionnel

SOURCES:

Keratin: Benefits and Uses for Hair

Keratin Hair Treatment Pros and Cons

Keratin: Protein, Structure, Benefits, Uses & Risks

Keratin: Types, Structure, Benefits, Uses, and Safety

Before and After: How a Keratin Treatment Changes Your Hair

Types of Keratin Treatments: Which One Is Right for You?