permanent hair straightening , also known as thermal reconditioning or Japanese straightening, is a chemical process that permanently transforms curly or wavy hair into straight hair. It is a popular method for individuals who desire long-lasting straight hair without having to use heat styling tools on a daily basis.The process typically involves several steps. First, the hair is washed and treated with a relaxant solution containing chemicals such as ammonium thioglycolate or sodium hydroxide. This solution breaks down the hair's natural protein structure, allowing it to be reshaped.Permanent hair straightening can take several hours, depending on the length and thickness of the hair. It is important to note that this process permanently alters the hair's structure, so the newly straightened hair will grow out with a natural texture.