Hair perming – what you need to know

Why are everybody’s hair not curly?

Hair shape is an inherent characteristic of every individual. A curve-shaped hair follicle gives rise to curly hair while a straight one gives rise to straight hair. By understanding what process in the body determine the shape of the hair follicles, someday a drug might be developed to change the shape of hair follicles.

Hair bonds

Hair is made up of a protein called keratin. The bundles (polypeptide chains) of keratin molecules in hair are held together by 3 type of side bonds:

• Hydrogen bonds – Hydrogen bonds are physical bonds. These are weak bonds that can be easily broken by water or heat. They can be reformed by drying or cooling the hair.
• Salt bonds – Salt bonds are also weak physical side bonds. These can be easily broken by weak alkaline or acid solutions and changes in pH.
• Disulphide bonds – Disulfide bonds are chemical side bonds. These bonds are stronger (but fewer) than hydrogen and salt bonds. Disulfide bonds cannot be broken by heat or water. The more disulphide bonds there are in a hair, the stronger it is. 

The disulphide bonds keep the keratin molecules fixed, so that the shape of the hair fiber stays the same. When you wish to change the shape of their hair (perming, straightening), these disulphide bonds need to be broken. Heat is an easy method of breaking these chemical bonds. This is the basic concept of hair perming.

How is hair perming done?

Perming process is quite similar to “rebonding” (hair straightening) process where hair is treated with chemicals to disrupt and rearrange covalent disulphide bonds in hair shaft.

Perming is a two-step process:

• Initially, a perming lotion is applied on hair that disrupts the bonds and chemically relaxes the hair. Mercaptans are used to soften the hair. Hair is wound over rollers or curling rods, to take their shape.
• Then, a fixing lotion that is a oxidising agent is applied on hair that fixes the cysteine bonds at new sites in curled hair shape.

Hair rollers are removed and hair is rinsed. Shampooing is advised two days later. Curled hair should be cleansed and conditioned with special curl enhancing products only. Avoid dye, highlight or any other chemical treatment of hair for next few months, to avoid extra damage of hair with chemicals.

The curls usually open a bit in a few weeks. A touch-up would be required for newly grown hair after 6-8 weeks.

Types of hair perming

Digital perm or hot perm

This process uses a combination of heat and chemicals to form looser curves and waves. Heating rods are used and hair is put in several rollers hooked to an electronic device that regulates temperature. If done properly, digital perming produces big, soft curls that are more defined when the hair is dry. The curls appear more natural. But this process is expensive and more time taking (3-4 hours) than cold perming.

Cold perm

This process perms use small and medium plastic curlers. It creates small, kinky to medium curls, which are more defined when wet or using styling products as mousse, gel or lotions. It is less expensive and less time taking than digital perms. It is the more commonly practised method of hair perming.

When should you avoid hair perming

Chemical treatment of hair can cause permanent damage to your hair. To avoid damage to your hair, you should avoid perming of your hair in the following situations:

• If your hair is already treated with chemicals, including hair colours and hair straightening chemicals
• If you have dry hair (perming would leave your hair more dry and frizzy)
• If your hair is fine (perms usually work better on thick hair)

Drawbacks of hair perming

• Chemicals used in perming damage outermost cuticle layer of hair. It makes your hair dry, frizzy and brittle, lacking tensile strength, more fragile and prone to breaking.
• Repeated use of chemicals on your hair can cause hair fall and baldness in long run
• Improper use of perming chemicals can cause scalp damage. Potent ammonium thioglycolate chemical solution can cause itching, redness, burning and peeling on scalp.
• Some women might experience perming as a painful and unpleasant procedure. Hair tightly wound on curlers or rollers can cause pulling or tearing of the hair which makes the pain even worse.
• Last but not the least, the most obvious disadvantage of hair perming is that you don’t know the outcome whether the curls would suit you or not.