Is applying hair protein using a flat iron considered among the "cauterization" mentioned in the Hadith that describes the people of Paradise who enter without reckoning or punishment, or is the Hadith specific to skin cauterization only? And does that deprive a person of the opportunity to enter Paradise without reckoning? And have scholars differed on its ruling? And does this protein prevent water from reaching the hair and head during ablution and ritual bathing?

It has been authentically reported from the Prophet, peace and blessings be upon him, that cauterization (al-kayy) is a beneficial medicine, yet he forbade it because it is contrary to the perfection of reliance upon Allah, and because it exposes the patient to severe pain. The process of protein treatment with a hair straightener is not among the forbidden types of cauterization, as it is not a medical treatment; rather, it is a heating of the hair to soften it and set the substance onto it. It does not cause pain and is considered an permissible adornment for women, provided it does not lead to harm or if the materials used are not impure. Protein treatment does not invalidate purity if it does not prevent water from reaching the hair.