Background: Hair represents a valued aspect of human individuality. The possibility of having an easy to handle hairstyle and changing it from time to time promoted an increasing search for chemical hair transformations, including hair straightening. Hair straightening is the process used to convert curly into straight hair. Aims: This review aims to discuss hair straightening, addressing techniques, products, methods of application, consequences to hair shafts, recommendations on this topic, and the risks involving the safety of both the user and the performing professional. Methods and Results: The terms “straightening” AND “hair,” “straightening” AND “alopecia,” and “straightening” AND “human hair” were used to perform a literature search in MEDLINE through PubMed until July 15, 2020. We limited the search to articles available in English, considering those mentioning alternatives to straighten the hair. We had a total of 33 relevant articles. Conclusions: This article will help dermatologists to advise their patients, providing a more suitable orientation on how to get the best outcome without risking one’s safety.

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