Keratin Straightening vs Chemical Straightening – How to Decide?

Keratin Straightening vs Chemical Straightening – How to Decide?

Posted by Peter McGuinness on

"I’ve been wanting to get my hair straightened for a long time, I’m tired of frizz and spending ages blow drying my hair. What is better, chemical or keratin straightening?" – Amanda


Hair is curly or out of hand and you spend hours straightening your hair every day of the week. You are on your last straw, enough is enough, you want control!

Some hairdressers swear by chemical straightening, while others recommend the keratin treatment without a doubt. What they say conflict, you are confused and want to make the right choice for yourself.

That’s why you are! You want to learn about the science behind the Keratin Treatment and decide what is the best way to straighten your hair professionally: Keratin Straightening or Chemical straightening?

 It can be confusing so we will help clarify and help you make a decision.


  • Difference between keratin and chemical straightening
  • Pros and cons of each treatment
  • How to decide which one is right for you


Keratin straightening uses a relatively new solution to straighten the hair called the Keratin Treatment. Your hair, skin and nails are made of keratin and just a few years ago scientists discovered how to break down keratin into its smaller amino acid compounds and were able to re-bind them to the hair, effectively repairing damaged hair with liquid hair.


The answer is, it depends. Every brand has its own formula. Some keratin treatments will straighten your hair but will not achieve what the industry calls a ‘pin-straight look’. The natural straightness has the advantage of being able to be styled and even curled which most people love the ability to choose to have a straight or styled look.

Along with straightening your hair, the treatment eliminates frizz, increases shine and also repairs your hair. Keratin treatments either use a low pH formula or formaldehyde (a toxic chemical) to achieve the hair straightening you are looking for. The low pH formula allows the keratin amino acids to bond the hair using heat. We recommend the low pH formula and to avoid any that contain formaldehyde.

PRO TIP: Terre a Mers formula is designed to Straighten Hair, is Formaldehyde Free and has been tested for peace of mind in Australian Labs. 


Keratin treatments are not a permanent treatment and do not affect your hair’s disulphide bonds like chemical straightening (which is a good thing). It instead coats your hair and fills up the porosity (gaps) with keratin. It lasts on the hair between 4 and 6 months depending on the formula and the technical process followed when application occurred and how well you maintain it. 

Keratin treatments are considered the natural alternative when choosing a hair straightening system as they use chemicals which don’t damage your hair. They also give you the flexibility to style your hair and it slowly wears out of your hair over time.


The other name for these treatments; Thermal Reconditioning, Reverse Perms, Japanese Straightening and Relaxers. How does it work? The simple explanation these treatments essentially break your hair's disulphide (internal) bonds using a strong chemical formulation of sodium hydroxide, ammonium thioglycolate to permanently straighten hair.

Disulphide what now? It changes the internal structure of your hair, effectively breaking the bonds which hold your hair together. This chemical change makes the effect permanent but damages your hair in the long term. It can even cause short term immediate damage.



The good (actually the very good) is that you can permanently straighten even the most tightly curled hair. Permanent means that your hair will remain straight until new hair is grown (regrowth). And in the past 90s and 00s, it was the go-to treatment (no keratin technology). It gives your hair the ‘pin-straight’ look’ which is the straightest hair you can get.


The bad is that the ingredients break your hair internally so that you can set the hair into a straighter alignment to achieve permanent straightening. Hair breakage can occur after a chemical hair straightening depending on the previous condition of the hair. You will also need to deal with regrowth in a few months when new hair grows which can make your hair look inconsistent.

hair breakage 

Other side effects cause your hair vulnerable for future damage, makes it brittle and super dry. You will need to give your hair continuous care. Most hair professionals do not recommend applying this straightening method on bleached, colour or highlighted hair and you will need to leave it for 2 weeks for your hair to recover.









  1. How healthy or damaged is your hair currently?

If your hair is currently damaged a chemical hair straightening application cause your hair to become weaker or at worst break or snap off in the future.If your hair is healthy chemical straightening would be an option to consider.

With a keratin treatment, your hair can be in almost any condition to do a keratin straightening. There is no risk of further damage, but it makes your hair healthier by getting the treatment done. Many people find getting your hair straightened and healthier at the same time is ideal.

  1. What is the end result you want to achieve?

If all you are aiming for is a ‘pin-straight hair’ and do not care about other factors such as hair damage or regrowth and you want to achieve the straightest look possible. Chemical hair straightening is probably the way to go.

If you want straight hair but are happy with a more ‘natural straightness’ and keeping your hair healthy is a high or equal priority to you then we would recommend a keratin treatment.

  1. Do prefer a more natural approach or a chemical approach?

We have noticed people a prioritising the healthier options in their life over the traditional chemical approach. These treatments both use chemicals to achieve the results wanted to perform hair straightening but the keratin treatment is a more natural and risk-free alternative.

There are no health benefits of a chemical hair straightening. It uses harsh chemicals in its formulas, which can possibly result in skin burns and over-processing if left on too long or if the hair technician does something wrong or is careless.

In contrast, the keratin treatment uses keratin amino acids which is broken down protein which is basically liquid hair which is its core ingredient. It also uses other ingredients such as shea butter to achieve the result of straight healthy hair. The actual keratin treatment is a lot lighter won’t irritate most skin and there is no risk for over-processing. This we view the keratin treatment view as a more natural and safer option.


The great thing is you have options to straighten your hair and get the control you want. This article is aimed to have shown you a comparison of both options so you can make an educated decision. At Terre a Mer we prefer the natural approach as it does not risk more hair breakage, makes your hair straight and healthier and you can still have the option for styling. We have done thousands of treatments and believe in what we do.

If you have any questions just comment below or call or email us we are happy to help.

To book a keratin hair straightening with us click here

PH: 1300 824 685


The Team at Terre a Mer

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  • Hi 6 weeks ago I had my chemical permanent straight on my hair, but it didn’t go well as I expected . Instead it damaged my hair. Should I do a keratin treatment? What is your advice thanks

    Ping on

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