TOXICOLOGICAL ANALYSIS OF HAIR IN FORENSIC TOXICOLOGY: APPLICATIONS, LIMITATIONS, AND CLINICAL AND EXPERT PERSPECTIVES

Resumo

Hair toxicological analysis has become an important tool in clinical and forensic toxicology due to its ability to detect long-term exposure to drugs of abuse, medications, and other chemical substances. Unlike conventional biological matrices such as blood, urine, and saliva, hair provides a wide detection window, allowing the reconstruction of an individual’s history of substance use over weeks or months. This study aimed to analyze the applications and limitations of hair toxicological analysis in clinical and forensic investigations, highlighting its relevance for detecting psychoactive substance use, the analytical methods employed, and the challenges associated with result interpretation. This is a qualitative, descriptive bibliographic review based on the analysis of scientific articles, books, international guidelines, and technical documents retrieved from national and international databases. The findings demonstrated that techniques such as Gas Chromatography–Mass Spectrometry (GC-MS) and Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS) provide high sensitivity and specificity, contributing to the reliability of toxicological examinations. However, factors such as external contamination, hair pigmentation, cosmetic treatments, hair growth rate, and the lack of universal standardization in result interpretation remain significant limitations to their application. It is concluded that hair toxicological analysis is a valuable scientific tool for clinical and forensic investigations, provided that results are interpreted comprehensively by considering laboratory, clinical, and forensic aspects, together with validated analytical protocols and internationally recognized technical guidelines.