Japanese hair straightening: what is it exactly?

Temps de lecture : 5 minutes environ

Let’s face it, standing in front of the mirror every week with a dodgy hair straightener, and getting burnt is not exactly what you’d call fun. It gets even worse when you step outside and it starts raining!

colored hair straighttening

Luckily, there is a permanent answer to all your hair straightening needs that you may not yet know about!  Japanese hair straightening (aka thermal reconditioning) unsurprisingly began life in Japan as more and more women desired the straight hairstyle permanently.

Since the early 2000s, it quickly travelled west and has been a particularly huge hit in the US. It’s a one-time, quick win to ensure sleek, straight hair forever! But how does it work exactly? Are there any risks, and how does it compare to other hair treatments? 

Here, we will explain everything you need to know about this unique treatment option.

The science behind the treatment

The process consists of four parts and works by re-structuring your hair’s chemical makeup. That’s right, stylists are also scientists! 

Let us explain:

  1. First of all, a chemical solution is applied to the hair to break down the structural bonds that give it those natural curls and frizz.  
  2. Next, the stylist thoroughly moisturises and conditions the hair to ensure it’s sleek and shiny before straightening.
  3. Then the hair is carefully straightened, in small sections, with hot iron tongs. This can be the longest process as they need to ensure it is completely straightened without causing damage to your hair. 
  4. Finally, another solution known as a neutraliser is applied to restore the hair’s bonds. This will lock them into place causing them to remain straight forever! 

In the 3 days following your appointment, it is important not to agitate your hair too much! Whilst the neutraliser is still taking effect, hair must be worn down to prevent creases or unpleasant indentations. 

Japanese hair straightening vs keratin treatment?

You’ve probably heard of the keratin treatment a little more than Japanese permanent hair straightening. It rose to fame as a temporary straightening solution and was originally seen as the ‘healthy’ option when it came to hair treatments. Both create the desired sleek, straight look, however, there are some significant differences.

Is it permanent?

Japanese hair straightening is a permanent treatment that completely alters your hair’s natural state. Hair will stay straight until it’s completely grown out. Keratin on the other hand is temporary, lasting only a few weeks, as it doesn’t break the bonds of your hair. 

While both cost around the same price, keratin treatment takes a lot longer and usually has to be spread out across two days. Japanese straightening only takes one session and the job is done! 

Which hair treatment is better?

It was also discovered that keratin contained a pretty strong chemical called ‘formaldehyde’. The side effects of which can be pretty nasty! It’s for this reason that the popularity of keratin treatment has diminished in recent years and Japanese hair straightening is seen as the most effective and less risky choice.  

Is Japanese hair straightening bad for your hair?  hair straightening

As with all chemically applied treatments, it carries certain risks. We are talking about permanently altering the state of your hair so caution, of course, needs to be exercised! 

Find out what condition your skin is in and whether it requires a fortifying treatment to make it stronger by consulting a hairdresser.

The chemicals used aren’t as damaging as the formaldehyde in keratin treatments. However, if your stylist has little experience or the straightening process is not performed with enough care, long-lasting damage is a possibility. Choosing the right stylist is extremely important, shop around and make sure they’re confident in performing the treatment.

Hair with previous colour treatments is also at higher risk of damage. The mixing of different chemicals, then breaking the hair’s bonds, and finally applying heat have clear risks so discuss with your stylist before making any hair and life-altering decisions. A little research, in the beginning, will go a long way in the end! 

Some other important questions you may have are outlined below:

How long does Japanese hair straightening last?

Although it’s seen as a process that will last forever, your hair will grow out at some point. It can last anywhere from six to ten months depending on how fast your hair grows!

How much does Japanese hair straightening cost?

Hold onto your hats because it’s certainly not the cheapest treatment option! Prices can vary between £350 and £700 depending stylist’s experience. The upside is that it could last the majority of the year and it certainly pays to go for quality over price! 

How long does Japanese straightening take?

The whole process is relatively quick compared to other treatments, lasting anywhere between 3-5 hours depending on the salon and stylist. 

So is Japanese hair straightening worth it?

This all depends on you and your needs! If you’re after permanently straight hair with relatively little upkeep and are happy to spend a bit more cash then absolutely. But our advice is to take some time to shop around, research and discuss with the professionals before making the ultimate commitment.


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