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How Do Perms Make Your Hair Curly?

By Author Hollee Wood

When you think of a perm, you probably think of some dry, frizzled 80’s hair. However, in reality, perms are used a lot in today’s world to add texture to hair. Trust me, they are a lot more common than you think. But have you ever asked yourself, “how do perms work”? I know I used to wonder about things like that before I went to beauty school. In this quick article, I want to teach you a thing or two about perms and the science that powers them…

When you think of perms, you probably think of frizzy 80's hair. However, they are more common then you think... but how do perms work?

Maybe you remember the famous scene at the end of Legally Blonde, in which Elle Woods cracks the case by talking about some perm science.

When you think of perms, you probably think of frizzy 80's hair. However, they are more common then you think... but how do perms work?

In case you were wondering, her explanation was pretty accurate….

First things first, the term, “perm” stands for “permanent wave”. Perms work by breaking down the hair structure and rebuilding it in a new form.

Step 1: Clarify

When you think of perms, you probably think of frizzy 80's hair. However, they are more common then you think... but how do perms work?

The first step of a perm is to wash the hair with clarifying shampoo. I usually will let the shampoo sit on the hair for a few minutes to make sure it gets all of the minerals and hair product buildup out of the hair. This will ensure even-penetration of the perm solution.

Step 2: Wrapping The Hair

When you think of perms, you probably think of frizzy 80's hair. However, they are more common then you think... but how do perms work?

There are a lot of different techniques on how to wrap a perm, and there are also different types of perm rods. What technique and type of rods you use, depend on what the desired end-result is. I’m not going to get too much into all of that in this article. If you want to learn more, there is a lot of good information about perm wraps on the internet. For the purpose of this article, the main thing you need to know is that the diameter of the perm rod will determine how tight the curl will be. For instance, if you are going for more of a body wave, I would suggest using bigger perm rods. If you are looking for really tight afro curls, you should use smaller rods.

If you are working with longer hair, the weight of the hair may pull down the curl, making it appear to be looser than it is. How you place the perm rods in position on the head, will also determine how the curls will fall.

Wrapping A Perm:

To wrap a perm, you want to be working with wet hair. You can spritz the hair down with a water bottle (or some perms come with pre-wrap solution) to make sure it stays damp. You want to section the hair into smaller sections (each section should be no wider than the perm rod). Then you will section each of those sections into smaller subsections (about the same size as the perm rod).

You want to fold an end wrap over the subsection of hair, and drag it all the way down to the bottom of the section. End wraps make sure the ends of the hair stay flat and smooth, which allows a more even penetration of the perm solution, while also protecting the ends from damage. Place the perm rod at the end of the hair and roll it up to the scalp. Use the locking mechanism of the perm rod to keep the rod in place.

Here is a quick video that shows you how its done:

Step 3: Applying The Perm Solution

When you think of perms, you probably think of frizzy 80's hair. However, they are more common then you think... but how do perms work?

Now that your hair is completely wrapped into perm rods, you will need to prepare it for the perm solution. Rope cotton is placed around the perimeter of the hairline to prevent the solution for falling into the customer’s face. I usually also hand the customer a towel to hold in case they have any dripping. To allow the optimal flow from the bottle, use a push-pin to poke a small hole into the top of the nozzle. To apply the solution, squeeze the bottle to allow enough solution to line the top of the perm rod and the bottom of the perm rod. You want to make sure the hair is completely saturated with perm solution.

After the hair is saturated, place a plastic cap over the hair (the perm should come with one). The inside of the cap will heat up with the aid of the body heat from the scalp. This helps the perm process. The amount of time that the perm solution stays on the hair is determined by the type of perm you use. Always follow the instructions on the box of the perm.

How Perm Solution Works:

Hair is made of keratin, a single protein with a long, helical shape. Keratin molecules are rich in the amino acid cysteine, which contains reactive sulfur atoms. Two cysteine residues on two mol­ecules of keratin can form a disulfide bond, a strong connection that links the keratin molecules, preventing them from slipping past each other. (YaleScientific.org)

Perm solution contains ammonium thioglycolate. This breaks down the disulfide bonds of the hair, allowing it to move freely. In other words, perm solution breaks down the shape of the hair.

Types of Perm Solution:

There are two types of perms that are used today…

The most common type of perm used is an alkaline perm, also known as a “cold perm”. This type of perm uses ammonium thioglycolate (like I mentioned above) to break down the disulfide bonds and they don’t need any external heat to process. This type of perm works best on virgin hair (hair that has not been chemically treated) and resistant hair.

Acid perms are slightly different. They have a lower pH level and are less damaging on the hair. Because of that, they should be used with damaged hair and fine hair. They use glyceryl monothioglycolate instead of ammonium thioglycolate, and do not produce as firm of a curl.

Step 4: Rinsing the Hair

When you think of perms, you probably think of frizzy 80's hair. However, they are more common then you think... but how do perms work?

Now that the disulfide bonds are broken down, you will want to wash the perm solution out of the hair. Do not remove the perm rods because we still need them. If you loose a few in the process, make sure to wrap them back in. Make sure to rinse all of the perm solution out of the hair by letting the water run over the hair until it eventually runs clean. This will usually take about 5 minutes of rinsing. Also, make sure to get all of the hard-to-reach places like the nape of the neck and around the ears.

Once the perm solution is all rinsed out, the hair will be pretty wet. Spend the next few minutes blotting the hair with a towel until it is damp. Make sure the hair is not dripping water; if it is that wet, it will not absorb the neutralizer correctly.

Step 5: Neutralizer

When the hair is damp, you will apply neutralizer in the same fashion that you applied the perm solution. The neutralizer rebuilds the disulphide bonds in their new shape (the shape of the perm rod). This is why the size of the perm rod determines how tight the curl is. Let the neutralizer process for 5 minutes.

Step 6: Rinse The Hair Again

At this point, I remove the perm rods while the neutralizer is still in the hair. Then, you want to rinse the hair again until the water runs clear. It should also take about 5 minutes.

After you are done rinsing, you should just towel-dry or air-dry the hair. If it is cold outside, or you want to dry it, do it without vigorously brushing through the hair. If you brush it, or style it right away, you risk pulling out the freshly-formed curls. It is also recommended that you don’t wet your hair for 24-48 hours after the perm.. that includes washing it. Let’s let Elle Woods tell us why:

Have you ever had a perm? Did you know how they worked before reading this article? I’d love to read your feedback in the comments section below…