Related Experiment Video
Updated: Apr 4, 2026

Collecting Hair Samples for Hair Cortisol Analysis in African Americans
Published on: June 10, 2018
Ethnic hair care products may increase false positives in hair drug testing
David A Kidwell1, Frederick P Smith2, Arica R Shepherd3
1Chemistry Division, Naval Research Laboratory, Washington, DC 20375, United States.
Abstract:
The question of why different races appear more susceptible to hair contamination by external drugs remains controversial. This research studied susceptibility of head hair to external cocaine and methamphetamine when hair products have been applied. Three different chemical classes of ethnic hair products were applied to Caucasian, Asian, and African hair. Some products increased the methamphetamine and cocaine concentrations in all hair types. A unique finding of this research is that certain ethnic hair products can replace moisture as a diffusion medium, thereby increasing the susceptibility to contamination over 100-fold compared to petroleum-based products.
Related Concept Videos
Drug Excretion: Miscellaneous Routes
Accessory Structures of the Skin: Hair Growth and Types
Accessory Structures of the Skin: Hair and Hair Follicles
Hair is a keratinous filament growing out of the epidermis. It is primarily made of dead, keratinized cells. Hair strands originate at the epidermal penetration called the hair follicle. The hair shaft is the part...
Multipotency and Niche of Bulge Stem Cell
Drug toxicity: Idiosyncratic Reactions
Pharmaceutical Alternatives: Excipients and Impurities-Related Therapeutic Nonequivalence

