Hair straightening is a hair styling technique which involves flattening and straightening of hair in order to give it a smooth and sleek appearance. It may be accomplished by using flat irons and hot combs, chemical relaxers, Japanese hair straightening, or Brazilian hair straightening. In addition flat irons and hair gels can help to make hair temporarily straight.

Flat irons and hot combs can only temporarily modify hair texture, whereas relaxers and the other methods permanently alter the structure, although new hair growth is not affected.

Japanese straightening, also known as thermal reconditioning or yuko straightening is a method for permanent straightening. Whereas other straightening procedures involve applying relaxers to smooth out the hair, in Japanese straightening the hair is treated with chemicals, then separated into sections. Each section is ironed, rinsed, and blow dried. The procedure takes from one to eight hours depending on the length, thickness and condition of the hair. The effect is permanent, though new growth is unaffected.

Brazilian straightening also called escova progressiva or Brazilian blowout is a method of temporarily straightening hair by sealing it with keratin with a flat iron.

Chemical straightening
Chemical hair straightening also known as relaxing is a procedure where the basic structure of curly hair is changed to straight form. This process utilizes strong chemicals that are applied directly to the shaft. It is best to have the relaxing process performed by a professional. After the treatment you must use the recommended protein rich shampoo and conditioner to wash. If the hair is not maintained properly then it may result in breakage and also loss.

Brazilian hair straightening
In Brazilian straightening or non-chemical treatment, a solution made with Keratin is applied to the hair and then sealed using a 450 degree flat iron. This product traps in moisture and hydrates the hair leaving it lustrous and smooth looking. This keratin treatment is found to have no side effects and makes the hair strong and healthy. This is a temporary straightening technique and lasts for 2 to 4 months. You have to use only sodium chloride free or sulfate free shampoos and conditioners to wash the hair after the treatment to avoid the salt content from stripping the keratin.

Brazilian straightening works best on chemically treated hair because the cuticles are open as all chemicals will raise the PH levels in the hair and that is what opens the cuticles and this enables the keratin to penetrate into the hair shaft.

There is Intant lizz of talk about the formaldehyde content in keratin treatment and many hesitate to take this treatment due to this reason. Formaldehyde is a colorless and pungent gas which can irritate the eyes and lungs if the fumes are inhaled. But off late many reputed brands have come out with formaldehyde free hair treatments which are absolutely safe to use.