Measurement of Hair Cortisol as a Retrospective Stress Marker: Effects of Prewashing, Pulverization, Temperature, and Sonication

This study investigated the efficiency of different methods for extracting cortisol from hair as a marker of chronic stress, using samples from 20 men. The methods compared included prewashing, cutting versus pulverization, and the application of temperature and sonication. Results showed that pulverization yielded higher cortisol levels than cutting (22.0 vs. 17.4 pg/mg, P = 0.002), but prewashing, temperature, and sonication did not significantly affect cortisol extraction. The study concluded that while pulverization was more effective, the large interindividual differences in cortisol levels suggest that any method could be used, considering the time and cost of analyses.