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Hair Smoothening: The Complete Guide With Pros & Cons

Hair smoothening can be an excellent way to put vibrance and life back into your hairstyle, but it can also have drawbacks. There are various techniques to smoothen your hair, and each has its own pros and cons.

Here, we’ll go over the types of hair smoothing techniques, how they affect the hair, and how long they will last so you have a better idea of whether or not you should smoothen your hair.

What Is Hair Smoothening?

Hair smoothening

Hair smoothening is a process that takes frizzy, dry hair and makes it straighter, shinier, and more vibrant. Stylists apply chemicals to the hair to make it appear smoother and healthier.

There are several types of hair smoothening treatments, which differ mainly in terms of their chemical compounds. It’s essential to know their differences when evaluating the pros and cons.

Types of Hair Smoothening

Formalin Hair Smoothening

Types of Hair Smoothening - Formalin

Formalin hair smoothening protects the hair shaft completely. They make the hair smoother, shiny, and straight. Studies show that hair is healthier and more elastic after using formalin smoothening chemicals than with other techniques. However, this method isn’t safe to do alone.

One of the byproducts of formalin is formaldehyde, which is very toxic to humans while the process is occurring. Once complete, it’s very safe to have formalin-smoothed hair.

However, while the mixture is doing its job, it must be handled by a professional.

Ammonium Thioglycolate Hair Smoothening

Ammonium Thioglycollate Hair Smoothening

Ammonium Thioglycolate uses the same chemicals as a perm, but it keeps the hair straight instead of curly.

These treatments are very effective, but your hair must be kept clean and dry for several days to maintain straightness while the product absorbs. While this is true for most hair smoothening treatments, it’s especially vital regarding Ammonium Thioglycolate.

Thioglycolate-based treatments don’t cause much harm to the hair in the short term, but they can do long-term damage, so consult a stylist before you take on this treatment.

Keratin Treatments

Types of Hair Smoothening - Keratin

Keratin is a very middle-ground approach to smoothening treatments. While some methods use harsh chemicals to apply the keratin, most people use heat instead.

Keratin is less likely to damage your hair than ammonium thioglycolate, but it doesn’t protect your hair as well as stronger treatments.

Like the other treatments, you cannot get your hair wet for several days after receiving a keratin hair smoothening. Additionally, you cannot put your hair up or let it get any kinks in it the first three days after your treatment.

Pros and Cons of Hair Smoothening

Now that you know a little more about different hair smoothing treatments, it’s time to look at the pros and cons.


  • You won’t have to worry about straightening your hair for 2-3 months.
  • Some types of hair smoothening treatments protect your hair.
  • Hair smoothening treatments can make damaged hair look sleek and shiny.
  • You can do some kinds of hair smoothening treatments at home.
  • Some hair smoothening treatments can lock in color and keep it looking fresh and vibrant.


  • You will not be able to wash your hair for 2-3 days.
  • With some types of hair smoothening, you won’t be able to put your hair up or use bobby pins or barrettes for three days.
  • Most hair smoothening treatments don’t last long if you go to the pool often.
  • Only professionals can perform some types of treatments, as they are dangerous.
  • You won’t be able to use a curling iron or a crimper on your hair if you want the smoothening treatment to last.

Things to Consider Before Smoothening Hair

If you are thinking about smoothening your hair, there are several things you should consider before going through with the procedure.

Do You Like To Alternate Your Hairstyles Frequently?

If you like to have your hair curled one day or straight the next, you probably shouldn’t smoothen your hair. Curling or waving your hair later will ruin the treatment.

Do You Have to Have Your Hair Up or in a Hairnet for Smoothening To Work?

Some hair smoothing treatments require you to leave your hair down for several days. If this is the case for you, you might have to wait until a holiday or a long weekend to get a hair treatment done.

Do You Have a Hobby Such as Swimming Which Puts You in Frequent Contact With Harsh Chemicals?

The chlorine in pool water reacts poorly with most hair smoothening treatments. While it isn’t likely to ruin your hair in one go (as long as it isn’t within the first few days of performing the procedure), it will decrease the time your hair will stay smooth.

How To Do Hair Smoothening

Process of Hair Smoothening

The process for smoothing your hair depends on which type you use. You should always follow the directions that come with the chemical that your hair-styling professional gives to you.

However, the process for hair smoothening generally goes as follows:

  • Wash and condition your hair as normal
  • Blow dry your hair if you’re using a keratin treatment. If you’re using a chemical treatment, leave your hair wet
  • Apply the hair smoothening chemicals to your hair
  • Do not allow the chemicals to touch your skin or scalp; wear gloves for protection
  • Allow the mixture to set in your hair as long as the directions or the hair stylist recommends
  • If you’re using a keratin treatment, flat iron your hair at this point. If you’re using a chemical treatment, rinse the product out without shampoo
  • With a chemical treatment, you will next blowdry your hair and use a flat iron to straighten it
  • If needed, add a smoothening cream
  • Allow any cream to sit in your hair according to the directions from the box or your stylist
  • Rince any cream from your hair
  • Regardless of the technique, you should avoid washing your hair with shampoo for a few days

Natural Ways for Smoothening Hair At Home

There are some natural smoothening remedies if you don’t want to use harsh, artificial chemicals on your hair. While they don’t last as long as professional treatments, they help hair look healthier and straighter!

Coffee Smoothening

smoothen hair naturally with coffee

Begin by brewing a pot of your favorite coffee, then let it cool to room temperature. Distribute it evenly onto your hair and let it sit for 10-15 minutes. Do not let the mixture touch your scalp, as it can stain the skin. Once it sets, rinse your hair with cool or lukewarm water.

Coffee smoothening typically lasts about three days but can last up to a week.

Egg and Honey Smoothening Mask

Egg and Honey Smoothening Mask

Mix two egg yolks with ⅓ cup of honey and three tablespoons of coconut oil to create a hair mask.

Apply the mask from the tips of your hair to the roots. The mask is excellent for hair and scalp and can decrease dandruff. Allow the mixture to set on your hair for 40 minutes and then wash and condition with lukewarm water.

This treatment should last approximately one week.

Honey and Oil Hair Smoothing

Honey and Olive Oil Hair Smoothing

This natural hair smoothening is slightly different from the other two methods. While the other two aim to smoothen the hair that has already grown from your scalp, the honey and olive oil mask attempts to make your hair straighter naturally.

Dampen your hair and apply a mixture of honey and oil in equal parts. You may use coconut oil or olive oil. Make sure to spread the mixture liberally onto your scalp. Allow the mixture to set for at least 20 minutes, and then wash your hair.

This treatment will make your hair shinier, but it will also make your scalp healthier. Any new hair growth should have a bit of extra moisture and shine.

After Care for Hair Smoothening

Whether you use professional or natural hair smoothening, there are several things to remember about caring for your straight and smooth hair:

  • Don’t wash your hair with harsh shampoos and conditioners.
  • Don’t use curing irons or wavers on smoothened hair.
  • The chemicals in pool water can harm your hair and ruin smoothening.
  • Hair ties and bobby pins aren’t good for some types of hair smoothening.

With a little patience and some extra care, you can make your hair smoothening treatment last.

Hair Much Does Hair Smoothening Cost?

Generally, professional smoothening costs between $75 and $300, depending on the type of treatment that you get. Prices can be a little higher or lower depending on what part of the country you live in.

If you do a natural treatment, you can generally smoothen your hair for a few days for less than $15.

How Long Does Hair Smoothening Treatment Last?

The length of time a hair smoothening treatment lasts depends on what type of treatment you get. Professional hair smoothening treatments typically last six to twelve weeks, and natural methods usually last between three days and one week. The better you care for your hair, the longer the treatment will last.


Now that you know more about hair smoothening treatments, here are some of the questions people frequently ask.

What is the difference between hair rebonding and hair smoothening?

Hair rebonding has the same goals as hair smoothening but is a much harsher treatment.

Hair rebonding lasts longer and works on stubborn, thick hair that a typical smoothening can’t tame. However, hair rebonding can cause severe damage to your hair.

Are hair smoothening and straightening similar?

The two are similar, but they aren’t the same. Hair smoothening is a semi-permanent procedure. It straightens the hair but uses chemicals to do it and makes the hair shinier.

Straightening hair is done with a flat iron and typically only lasts until the next time you get your hair wet. Read more in our post about the differences between hair smoothening and hair straightening.

Can I do hair smoothening if I am pregnant?

Yes. However, some hair treatments are safer than others. Avoid formalin-based hair smoothening treatments if you are pregnant, but most keratin treatments are safe for pregnant women and their children.

Always confirm with a professional that the treatment you want is safe before proceeding.

Can hair smoothening cause hair to fall out?

Hair smoothening shouldn’t cause your hair to fall out. However, most hair smoothing techniques do cause minor damage to your hair.

If your hair has already suffered from damage, consider the method that won’t cause much more damage, such as formalin or keratin treatments.

Are there any side effects of hair smoothening?

Side effects depend on the hair smoothening method that you use. Ammonium Thioglycolate can cause damage to the cuticle of your hair. If you misuse it, formalin can cause the same side effects as exposure to formaldehyde.

Should I apply oil after hair smoothening?

Depends! For some hair smoothening techniques, this will help. For others, it will hurt. Read the instructions carefully to see if it will help.

Can I smoothen my curly hair?

It depends. If your hair is frizzy or lightly curly, you can likely smoothen your hair. If you have tight, thick curls, you may need to consider hair rebonding instead.

Can I permanently smoothen my hair?

Hair rebonding can be permanent, but chemical smoothening methods are not. Hair smoothening can last up to twelve weeks, but it does not last forever. 

There are many ways to smoothen your hair, each with pros and cons. Be sure to carefully consider each type of hair smoothening technique so you can use the best method for you and your hair!