Hair is primarily made up of protein, called keratin and grows from a follicle, which is a sac. Proteins have sulphur atoms and when two sulphur atoms combine they form a disulphide bond. The texture of our hair mainly depends on the disulphide bond. The greater the number of these bonds, the curlier our hair would be and vice versa.
The percentage of humidity in the air not only determines how our hair looks but also its straightness or curliness. When there is more humidity, its effect forces the water to return to hair fibre. This affects the protein structure of the hair, forcing it to become original. No matter how many times a person gets his or her hair straightened, the new hair that grows will always be in its original form.
