Methodological Considerations for Hair Cortisol Analysis: Effects of Resuspension Solution, Hair Weight, Extraction Duration, and Degree of Hair Shredding on Hair Cortisol Concentrations

This study addresses methodological factors affecting hair cortisol concentration (HCC) analysis, focusing on resuspension solutions, hair weight, extraction duration, and hair shredding. The researchers used a standard protocol to analyze hair samples, examining the impact of ultra-pure water versus phosphate buffer for resuspension, the effect of hair sample weight (5 mg, 7.5 mg, 10 mg) on HCC, and varying extraction durations (20, 24, 72 hours). They also investigated the influence of hair shredding methods on cortisol extraction. The study highlights the need for standardized procedures due to variability in practices across laboratories, as current findings on these factors are scarce and inconclusive.